A little bit about ASO Titers

[Buster]

In reading through multiple posts, it seems there is a lot of confusion about titers and carriage of streptococcal infection. As a parent struggling to understand the medical information, I wanted to post what I've learned thus far and I hope it will be of use to you.

 

1) Titers need to be compared to a baseline. Direction is much more important than absolute value.

Some people produce very significant antibody responses, some don't. Some have high baselines, some don't. Since most often there isn't a test result from the prior month to compare against, most doctors (and labs) use a measure known as the "upper limit of normal" [uLN] as defining the baseline for ASO tests. Then if your single sample is > 130%-150% (depends on lab) of this baseline, they consider the test positive.

 

2) So this begs the question of what is the ULN for ASO? There are lots of studies here but what is important is that the studies have a very large range. For example in one study, kids not suspected of GABHS strep in the 5-10 year range, had

• 48% had titers below 100
  
• 6.8% had titers of 100
  
• 10.6% between 101-125
  
• 7.6% between 126-156,
  
• 22.1% between 157-195
  
• and 4.5% in 196-244
  

Unfortunately, even in this study, there didn't seem to be a second measurement taken within 1-2 weeks to look for rise/decline.

 

3) This begs the question of "what level of response consistitutes a positive?." Could a result of <100 still be an indication of a recent strep infection?

The answer appears to be yes, but only if you have a prior value done by the same lab, using the same technique. Most studies show that subjects will have a response 2-4x their baseline, this statistically could still fall within this "normal" range depending on the individual. So again, the importance is to look at trends and not absolute values.

 

4) What about falling titers? Does a high number indicate a current strep infection?

The answer seems to be no. There is just no good study about how fast ASO titers fall and what drives the rate of fall. Thus a single sample really gives no good indication of direction. Most studies agree that the rise is within a week of infection with a peak at 4 weeks, but there isn't a study of whether this peak remains if the initial infection goes untreated. So could someone with an untreated strep infection have a declining ASO titer? -- the answer appears to be yes.

 

For example, the most recent study by Kurlan [June 2008 - Pediatrics] has one subject that has positive throat cultures for 23 of 25 months but the ASO titers are falling within this entire time. What does this mean? No one knows.

 

5) Do all strains of strep produce an ASO reponse?

 

The best study I've found on this is Kaplan's 2003 paper "Immune Response to Group A streptococcal C5a Peptidase in Children: Implications for Vaccine Development." What this paper shows is that despite positive strep cultures on day 1, at a subsequent visit 4 weeks later,

• 46% of subjects presented no ASO rise,
  
• 55% presented no Anti-DNAseB rise,
  
• and 37% presented no rise of either ASO nor Anti-DNAseB
  

There also seems to be good research indicating that skin GABHS infections does not produce ASO response despite producing Streptolysin O.

 

What does this mean?

Does this mean that the test was bad? That some strains don't produce the streptolysin O protein? That some people don't mount a high immune response? That the individual is a strep carrier? That the strep was going on for some time and the ASO titers have already fallen? That skin GABHS infection differs from pharangytis GABHS? The answer is that the scientific community doesn't know. There has been no careful study of the decline rate of ASO titers and the entire field of "strep carriers" is not at all clear.

 

So summarizing,

• a rising ASO titer (regardless of absolute value) is an indication of GABHS strep; however, you need a baseline to be sure it is rising.
  
• A falling ASO titer indicates that there was strep, but no one knows when.
  
• A high ASO titer could be anything including that the titer is falling, rising, or just a high baseline. Statistically it is likely to be a falling titer.
  
• Most will treat a titer of > 400 IU's as a falling titer (i.e., that there was once a strep infection sometime in the past). But the exact time of the infection is not known.
  
• The interpretation of a low ASO titer is unclear. There could have been an infection and the titer has already fallen, the baseline for the person could be low, the individual may not respond with a strong immune response, the strain may not produce significant amounts of streptolysin O.
  

One final comment, Swedo does not require high ASO titers or even rising ASO titers to diagnose PANDAS. The titers are checked only when a positive strep culture is not available and you are retroactively looking for an indication of past infection. The flaw with using titers as an indication of prior strep infection is (as I stated above) that "low" values can still be associated with prior strep infections since the rate of ASO titer decline is not known, most people only have a single sample, and the ASO response is variable across individual and strep type.

 

Regards,

 

Buster

[hopefulinsc]

Thank you for the valuable information. We just heard back from the doctor relative to our daughter's blood work and throat culture. The throat culture came back negative and they indicated that the ASO titer and AS Dbnase (not sure if I wrote the 2nd one correctly came back within normal levels. The first time she was in fact diagnosed with strep, however, the culture was scant. They did prescribe antibiotics and all the symptoms went away. She was back to normal. This episode is much much milder than the 1st one and we are actually wondering if this was brought on by the HEP A booster shot that she received. The first time we went thru all the OCD symptoms. However, so far, this time around we are seeing confusion, memory impairment and hyperactivity. Otherwise, she's in good spirits (not so, the first time around). But, there is no doubt about the fact that something is definitely going on. Do you know if this can be brought on by immunizations? How does one find a doctor qualified to make a diagnosis? I feel like I know more about this than most doctors. She has been, up-to-this-point, a very happy, healthy little person (she's five, soon to be six).

 

Any feedback you can provide would be very appreciated.

 

In reading through multiple posts, it seems there is a lot of confusion about titers and carriage of streptococcal infection. As a parent struggling to understand the medical information, I wanted to post what I've learned thus far and I hope it will be of use to you.

 

1) Titers need to be compared to a baseline. Direction is much more important than absolute value.

Some people produce very significant antibody responses, some don't. Some have high baselines, some don't. Since most often there isn't a test result from the prior month to compare against, most doctors (and labs) use a measure known as the "upper limit of normal" [uLN] as defining the baseline for ASO tests. Then if your single sample is > 130%-150% (depends on lab) of this baseline, they consider the test positive.

 

2) So this begs the question of what is the ULN for ASO? There are lots of studies here but what is important is that the studies have a very large range. For example in one study, kids not suspected of GABHS strep in the 5-10 year range, had

• 48% had titers below 100
  
• 6.8% had titers of 100
  
• 10.6% between 101-125
  
• 7.6% between 126-156,
  
• 22.1% between 157-195
  
• and 4.5% in 196-244
  

Unfortunately, even in this study, there didn't seem to be a second measurement taken within 1-2 weeks to look for rise/decline.

 

3) This begs the question of "what level of response consistitutes a positive?." Could a result of <100 still be an indication of a recent strep infection?

The answer appears to be yes, but only if you have a prior value done by the same lab, using the same technique. Most studies show that subjects will have a response 2-4x their baseline, this statistically could still fall within this "normal" range depending on the individual. So again, the importance is to look at trends and not absolute values.

 

4) What about falling titers? Does a high number indicate a current strep infection?

The answer seems to be no. There is just no good study about how fast ASO titers fall and what drives the rate of fall. Thus a single sample really gives no good indication of direction. Most studies agree that the rise is within a week of infection with a peak at 4 weeks, but there isn't a study of whether this peak remains if the initial infection goes untreated. So could someone with an untreated strep infection have a declining ASO titer? -- the answer appears to be yes.

 

For example, the most recent study by Kurlan [June 2008 - Pediatrics] has one subject that has positive throat cultures for 23 of 25 months but the ASO titers are falling within this entire time. What does this mean? No one knows.

 

5) Do all strains of strep produce an ASO reponse?

 

The best study I've found on this is Kaplan's 2003 paper "Immune Response to Group A streptococcal C5a Peptidase in Children: Implications for Vaccine Development." What this paper shows is that despite positive strep cultures on day 1, at a subsequent visit 4 weeks later,

• 46% of subjects presented no ASO rise,
  
• 55% presented no Anti-DNAseB rise,
  
• and 37% presented no rise of either ASO nor Anti-DNAseB
  

There also seems to be good research indicating that skin GABHS infections does not produce ASO response despite producing Streptolysin O.

 

What does this mean?

Does this mean that the test was bad? That some strains don't produce the streptolysin O protein? That some people don't mount a high immune response? That the individual is a strep carrier? That the strep was going on for some time and the ASO titers have already fallen? That skin GABHS infection differs from pharangytis GABHS? The answer is that the scientific community doesn't know. There has been no careful study of the decline rate of ASO titers and the entire field of "strep carriers" is not at all clear.

 

So summarizing,

• a rising ASO titer (regardless of absolute value) is an indication of GABHS strep; however, you need a baseline to be sure it is rising.
  
• A falling ASO titer indicates that there was strep, but no one knows when.
  
• A high ASO titer could be anything including that the titer is falling, rising, or just a high baseline. Statistically it is likely to be a falling titer.
  
• Most will treat a titer of > 400 IU's as a falling titer (i.e., that there was once a strep infection sometime in the past). But the exact time of the infection is not known.
  
• The interpretation of a low ASO titer is unclear. There could have been an infection and the titer has already fallen, the baseline for the person could be low, the individual may not respond with a strong immune response, the strain may not produce significant amounts of streptolysin O.
  

One final comment, Swedo does not require high ASO titers or even rising ASO titers to diagnose PANDAS. The titers are checked only when a positive strep culture is not available and you are retroactively looking for an indication of past infection. The flaw with using titers as an indication of prior strep infection is (as I stated above) that "low" values can still be associated with prior strep infections since the rate of ASO titer decline is not known, most people only have a single sample, and the ASO response is variable across individual and strep type.

 

Regards,

 

Buster

[lurker]

Hopeful,

 

Many of us here, myself included, feel that our children have reacted to vaccines. My son's tic disorder began three days after a DTaP booster. It took three months to go away. Now every time he gets sick, we will see low grade symptoms resurface. (Nothing has been close to even 10% of the aftermath of that shot.) He had walking pneumonia and got a tic; he had a tummy ache and fever and got a tic. He gets the tic about three days before I know he is sick (It's not fun being me for those three days either ). It appears that when his immune system is activated, he tics.

 

My kid doesn't have PANDAS, but I can promise you this -- if he got strep, he would tic. As for your daughter, I really do think it could be the shot. Consider yourself lucky her reaction wasn't as severe this time. And, as I like to remind myself every now and again, vaccines are a lot easier to avoid than strep!

[hopefulinsc]

Lurker:

 

I have seen no information on line relative to whether these OCD symptoms and/or tics produce and permanent lasting effects in terms of any brain damage. Do you have any ideas or information on this subject?

 

The worse that we experienced, and we are hoping we are now on the tail end of this episode, is the regressive behavior and hyperactivity.

 

I know what you mean about "wacko". I think I'm aging prematurely with all of this. The first time around, I couldn't eat, or sleep and was totally preoccupied with this. It's terrible and I hope the medical field is trying to work on figuring this out. I can't believe that the pediatricians don't even know anything about this. I think that there are probably many children going undiagnosed due to ignorance on the part of the pediatricians.

 

Hopeful in sc

 

Hopeful,

 

Many of us here, myself included, feel that our children have reacted to vaccines. My son's tic disorder began three days after a DTaP booster. It took three months to go away. Now every time he gets sick, we will see low grade symptoms resurface. (Nothing has been close to even 10% of the aftermath of that shot.) He had walking pneumonia and got a tic; he had a tummy ache and fever and got a tic. He gets the tic about three days before I know he is sick (It's not fun being me for those three days either ). It appears that when his immune system is activated, he tics.

 

My kid doesn't have PANDAS, but I can promise you this -- if he got strep, he would tic. As for your daughter, I really do think it could be the shot. Consider yourself lucky her reaction wasn't as severe this time. And, as I like to remind myself every now and again, vaccines are a lot easier to avoid than strep!

[Buster]

I've gotten a lot of questions regarding ASO titers and there seems to be some confusion about titers and PANDAS. Hope the following helps:

 

1) Is PANDAS a reaction to elevated ASO or AntiDNAseB titers?

The research indicates no. ASO and AntiDNAseB are responses (antibodies) to exotoxins from Group A Beta-Hemolytic Streptococci. PANDAS is thought to be a reaction to another antibody that's created in response to the streptococci. The theory from Cunningham and Kirvan is that there is a monoclonal antibody that is created that targets a particular carbohydrate sequence on the streptococci. This monoclonal antibody is supressed in most people but for some reason it is not supressed in PANDAS kids.

 

2) What amount of streptococcus is necessary to cause a detectable rise in ASO and AntiDNAseB?

This is unknown. Some people respond with high antibody counts while others have low counts. It is just not understood. Studies in 2003 by Shet and Kaplan indicate that ASO rises in 53% of patients with culturable strep, AntiDNAseB rises in 45% of patients with culturable strep, and either ASO or AntiDNAseB rises in 60% of patients with culturable strep (i.e., 40% don't have such a rise).

 

3) Does an elevated ASO or AntiDNAseB indicate a persistant strep infection?

Apparently not. Some people keep high AntiDNAseB for years. The rate of fall is just not known.

 

4) Is a high ASO or AntiDNAseB bad?

It is unclear, it indicates the body is still producing antibodies to antigens from strep, but PANDAS is likely related to a different antibody and it is not at all clear if the rise/fall of this antibody is linked to the ASO or AntiDNAseB titer.

 

5) Is there a test for this antibody associated with PANDAS?

Not yet. There remains considerable debate about the antibody and whether the antibody causes inflammation or just interference with basal ganglia function. Swedo and others thought the debate over PANDAS would end when the antibody was discovered. Unfortunately, others have not properly repeated Kirvan and Cunningham's experiment and others have had difficulty correctly identifying PANDAS patients.

 

 

Regards,

 

Buster

Edited December 30, 2010 by Buster

[Chemar]

Hi Buster

 

you may want to link to this thread in the essential threads sticky so others can easily find it.

 

thanks for the helpful info

[browneyesmom]

Bumping - great info within!

[Priscilla]

Thanks Buster. I have also noticed some reports of titers rising after abx. I was thinking about how Lyme antibodies can rise after abx due to the changing of the organism (possibly migration???) Got me wondering if an intracellular strain of Strep lurking could cause the same response (increase in titers after abx) Any thoughts??

[Buster]

Hi Priscilla,

 

Abx do not remove the antibodies so the ASO or AntiDNAseB will still rise. Abx can limit the # of antibodies by helping the immune system by slowing the advancement of bacterial infection. Those who have ASO rise will have the rise 1-4 weeks after the initial infection and have a rise in AntiDNAseB 6-8 weeks post infection. The rate of fall is not known (literally no studies).

 

Please recall that ASO and Anti-DNAseB are responses exotoxins of the strep, not to the strep itself.

 

Regards

 

Buster

 

Thanks Buster. I have also noticed some reports of titers rising after abx. I was thinking about how Lyme antibodies can rise after abx due to the changing of the organism (possibly migration???) Got me wondering if an intracellular strain of Strep lurking could cause the same response (increase in titers after abx) Any thoughts??

[Priscilla]

Hi Priscilla,

 

Abx do not remove the antibodies so the ASO or AntiDNAseB will still rise. Abx can limit the # of antibodies by helping the immune system by slowing the advancement of bacterial infection. Those who have ASO rise will have the rise 1-4 weeks after the initial infection and have a rise in AntiDNAseB 6-8 weeks post infection. The rate of fall is not known (literally no studies).

 

Please recall that ASO and Anti-DNAseB are responses exotoxins of the strep, not to the strep itself.

 

Regards

 

Buster

 

Thanks Buster. I have also noticed some reports of titers rising after abx. I was thinking about how Lyme antibodies can rise after abx due to the changing of the organism (possibly migration???) Got me wondering if an intracellular strain of Strep lurking could cause the same response (increase in titers after abx) Any thoughts??

 

 

I understand the abx don't remove antibodies, and may help supress infection progression "if" there is still an infection (may be even property of some abx). I guess it just gets complicated when there hasn't been ANY sign of infection for at least 3-4 months, and antibodies are elevated (our case). Of course as you said, we don't know how long it takes for them to fall, but the severe exacerbation of symptoms was not until 3-4 mos post illness, and it was the ASO that was elevated. Then I get stumped on why abx work so well, symptoms resurge when off abx, then they work again. So as speculated, either the antibody production doesn't shut down (even in the absence of infection), or the infection persists, in our case, with No signs or symptoms of infection. Then a child could be doing ok, and exacerbate without a strep illness. Again, either glitch in antibody production, or a low lying chronic infection resurfacing. (So just thinking outloud online) I am wondering if it is an infection, why has it become so hard to erradicate, even after months of abx- has this strep morphed into a "superbug", and enabled itself to hide from abx, then trigger this immune response again and again. I know we don't have all the answers we want (if we did, we wouldn't be here). Just my PANDAS mom mind spinning again. Thanks

[Buster]

Hi Priscilla,

 

There are five main theories why antibiotics might be effective (despite negative throat culture for GABHS):

1. Antiinflammatory properties
   
2. Intracellular strep
   
3. Immunomodulating properties
   
4. non-strep based infection
   
5. someone else in house is a carrier
   

 

1. Azithromycin in particular is antiinflammatory and so you might be seeing that effect.
   
2. Certain M-strains of GABHS have been shown to go intra-cellular. This means the bacteria is acting more like a virus. As the cell bursts (or is destroyed by a macrophage) the bacteria can reenter the blood stream and the immune system responds again. This is one possible explanation of a chronically elevated titer. It also could help explain why Augmentin XR is being effective.
   
3. Azithromycin is immunomodulating (shifting Th2 to Th1). Th1 tends to target intracellular infections.
   
4. There may be another infection (such as mycoplasma pneumonia) that is being contained by the abx. When the abx stop, the infection returns.
   
5. Finally, what you might be seeing is recolonization from an active carrier in the house (i.e., that when you stop abx you are essentially getting recolonization or a ping-pong effect). This is why we tend to recommend checking all in the house if you are seeing a canary effect.
   

 

Best regards,

 

Buster

 

 

I understand the abx don't remove antibodies, and may help supress infection progression "if" there is still an infection (may be even property of some abx). I guess it just gets complicated when there hasn't been ANY sign of infection for at least 3-4 months, and antibodies are elevated (our case). Of course as you said, we don't know how long it takes for them to fall, but the severe exacerbation of symptoms was not until 3-4 mos post illness, and it was the ASO that was elevated. Then I get stumped on why abx work so well, symptoms resurge when off abx, then they work again. So as speculated, either the antibody production doesn't shut down (even in the absence of infection), or the infection persists, in our case, with No signs or symptoms of infection. Then a child could be doing ok, and exacerbate without a strep illness. Again, either glitch in antibody production, or a low lying chronic infection resurfacing. (So just thinking outloud online) I am wondering if it is an infection, why has it become so hard to erradicate, even after months of abx- has this strep morphed into a "superbug", and enabled itself to hide from abx, then trigger this immune response again and again. I know we don't have all the answers we want (if we did, we wouldn't be here). Just my PANDAS mom mind spinning again. Thanks

[Priscilla]

Hi Priscilla,

 

There are five main theories why antibiotics might be effective (despite negative throat culture for GABHS):

1. Antiinflammatory properties
   
2. Intracellular strep
   
3. Immunomodulating properties
   
4. non-strep based infection
   
5. someone else in house is a carrier
   

 

1. Azithromycin in particular is antiinflammatory and so you might be seeing that effect.
   
2. Certain M-strains of GABHS have been shown to go intra-cellular. This means the bacteria is acting more like a virus. As the cell bursts (or is destroyed by a macrophage) the bacteria can reenter the blood stream and the immune system responds again. This is one possible explanation of a chronically elevated titer. It also could help explain why Augmentin XR is being effective.
   
3. Azithromycin is immunomodulating (shifting Th2 to Th1). Th1 tends to target intracellular infections.
   
4. There may be another infection (such as mycoplasma pneumonia) that is being contained by the abx. When the abx stop, the infection returns.
   
5. Finally, what you might be seeing is recolonization from an active carrier in the house (i.e., that when you stop abx you are essentially getting recolonization or a ping-pong effect). This is why we tend to recommend checking all in the house if you are seeing a canary effect.
   

 

Best regards,

 

Buster

 

 

I understand the abx don't remove antibodies, and may help supress infection progression "if" there is still an infection (may be even property of some abx). I guess it just gets complicated when there hasn't been ANY sign of infection for at least 3-4 months, and antibodies are elevated (our case). Of course as you said, we don't know how long it takes for them to fall, but the severe exacerbation of symptoms was not until 3-4 mos post illness, and it was the ASO that was elevated. Then I get stumped on why abx work so well, symptoms resurge when off abx, then they work again. So as speculated, either the antibody production doesn't shut down (even in the absence of infection), or the infection persists, in our case, with No signs or symptoms of infection. Then a child could be doing ok, and exacerbate without a strep illness. Again, either glitch in antibody production, or a low lying chronic infection resurfacing. (So just thinking outloud online) I am wondering if it is an infection, why has it become so hard to erradicate, even after months of abx- has this strep morphed into a "superbug", and enabled itself to hide from abx, then trigger this immune response again and again. I know we don't have all the answers we want (if we did, we wouldn't be here). Just my PANDAS mom mind spinning again. Thanks

 

 

ok, so not to bug you, again I am working this out in my mind trying to process and eliminate- just sharing in case anyone would want to know. Here is what I am thinking (just for us)

 

1- zith didn't really work for us, couldn't give it much chance because her her stomach too much

 

2- REELING ME IN- this is what I am wondering about for us- history of pneumonias, studies on alveolar macrophages show phagocytosis and internalization of the strep. Repeated bouts of pneumonia started after a prolonged diagnosis on a strep throat infection as a baby. Strep antibodies were elevated, and Augmentin XR is effective

 

3- Not using zith so I am crossing this off

 

4- Possibility of lingering mycoplasma- but strep antibodies elevated with sudden exacerbation-leans me more towards strep

 

5- Could be possible, but never a problem before 8 yrs old- understandably something has triggered this process, now maybe more sensitive

 

Also we have done ivig with success, even off abx for 2 months. But 2 months after last infusion she had a 2 day fever and cough, then relapsed. That is why we have restarted abx. Immunomodulation should have been achieved with ivig, would ivig help fight an intracellular strep?? Hard to say, but the arrow is pointing towards the possibility of a resistant strep. Thanks for your input, again, I am just thinking out loud, trying to narrow down the list of what could be going on here. The list of causes in the PANDAS/PITAND world seems to be growing, as if dealing with the illness isn't enough. I appreciate your time, don't feel obligated to entertain me, I do appreciate your input though. Hope you have a HAPPY NEW YEAR full of positive change. Thanks for all you do.

[Buster]

1- zith didn't really work for us, couldn't give it much chance because her her stomach too much

 

Typically zith is way easier on the stomach than Augmentin XR.

 

2- REELING ME IN- this is what I am wondering about for us- history of pneumonias, studies on alveolar macrophages show phagocytosis and internalization of the strep. Repeated bouts of pneumonia started after a prolonged diagnosis on a strep throat infection as a baby. Strep antibodies were elevated, and Augmentin XR is effective

Certainly possible. When you say Strep Antibodies were elevated did you have a baseline? Usually GABHS isn't accompanied with a cough.

 

 

4- Possibility of lingering mycoplasma- but strep antibodies elevated with sudden exacerbation-leans me more towards strep

 

I'd recommend being careful about putting too much stock in ASO or Anti-DNAseB unless you have a prior reading 2 weeks earlier. ASO and AntiDNAseB are measured from a rise in titer, not from stable values.

 

5- Could be possible, but never a problem before 8 yrs old- understandably something has triggered this process, now maybe more sensitive

That is exactly the point. The immune system is now primed. Think of it like someone with an allergy. Now that the body has learned an abnormal recipe for response, it's primed.

[norcalmom]

Just wanted to share a couple things we've found with my son over the past 18 months. DS did not culture positive, or have high titers for strep. We do believe he had peri-anal strep, which would not cause rise. HOWEVER he has astronomically high IgG for mycoplasma 2430 (normal under 100) but IgM for mycolplasma is inside the normal range. From what I have found about these titers, there is even less information on them than strep titers. According to my doctors (one local, and Dr K) the high IgG doesn't mean anything. Means he had an infection, and it could stay high for over a year. IgM indicates that there is no active infection, however the studies I've read seem to debate if a prc (pcr?) test would be better.

 

He's been on Azith for over a year. Which SHOULD have cleared any mycoP. Full dose for most of the time. At the beginning he had some stomach issues, which he fairly quickly adjusted to. Things that helped with this were - I broke the dose in two. gave half in morning, half at night. Also, I give the one in the morning with food, or food within a half an hour or so. Mostly I think he jsut got used to it. I can give him a full does now on an empty stomach and it doesn't bother him (I still break it up tho). We went to a gastroenterologist and got a bunch of tests when we first went on Zith, no yeast, c-diff or celiacs, but did discover low IgG at that time..I am glad I decided to leave him on this antibiotic.

 

DS does not have ANY history of strep throat. According to our medical records, his sister had it once. He did however have pnemonia at age 6. And, also he makes only one antibody of the 14 serotypes tested for strep pnemoniae. And yes, he went thru some "phases" between 6 and 10ys that were probably missed exacerbations.

 

DS is pitand. He will react to viruses. Although, no exacerbation was as bad as the one that I think was initially caused by the perianal strep. AND I find he reacts differntly to differnt things. For example, he had a stomach flu last spring, that only cause a 3 day exacerbation, where a slight cold set him off for weeks.

 

Now that I know a little more about mycolplasma (walking pnemonia) I realize that slight cold, could have been mycop. One of the hallmarks is an unproductive cough. (which, as Buster noted, is not usually present in strep throat). I think we just got lucky that that was the antibiotic our doc first prescribed.

 

DS is now almost 4 months post IVIG. He is doing well, but still has one very annoying OCD thing and is subclinical with irritability and some other stuff, but a mom would noticel). Prior to ivig he had the gammut of symptoms - tics, compulsion, insomnia, bedwetting, OCD...the list goes on. HIs numbers have improved since ivig, pretty much correlating to his severity. the blood draws prior to ivig were at baseline, not in exacerbation.

 

prior to ivig [b3 mos. ]Post ivig[/b]

IgG 680 low 801 normal!

IgG sub1 386 low 396 still low all other subclasses normal before and after

CamK II 176 high 131 borderline low pandas/high normal range

Antilyso. 640 high 160 normal!

Anti Dop 1 1000 normal 2000 borderline high. all other cunningham tests exactly the same before an after. In normal range.

 

We tested him for Lyme and mycoP AFTER ivig, so don't have any before data. Lyme was inconclusive. We have an appointment with LLMD in one week. This LLMD has experience with mycoP, and other intercellular bacteria, and in addition to full lyme eval, will be asking about perhaps adding another antibiotic or switching. I really just want to run out and get another ivig - since his improvement seems to have stopped, and Dr K said if he slides back or stops, another ivig might be in order. But, my gut is telling me that DS's key is the mycoplasma-doesn't make strep pneumonie antibodies - lowish IgGand sub 1 - autoimmune issues. And the solution might be another ivig, or might be switch or adding an antibiotic.

 

And, if we do another ivig, I'm going to wait until the brunt of cold an flu season is past.

 

Hope that helped anyone with PITAND or possible "walking pneumonia" issues. I think that both strep and mycoP are so ubiquitous that our kids should be tested for both at initial screening, not just the strep. Of course it has taken decades just to get proof for strep connection, I'm not holding my breath! And, since the initial infection - can be MONTHS before first exacerbation, we ALL probably missed whatever the fist trigger was. It isn't until later that the infection and the pandas symptoms come concurrently. This is way everyone should be consulting with either a pandas expert..that will be checking for immune disorder and other infections, or pandas friendly doc that understands that absence of strep or titers...doesn't mean the child doesn't have pandas, or, another another underlying infection.

[pandakid11]

HI

The thing that doesn't make sense is that by going off anti-biotics, the PANDAS symptoms get worse. Why? It has

to be the titers that are causing this, no? Thanks

 

 

 

 

In reading through multiple posts, it seems there is a lot of confusion about titers and carriage of streptococcal infection. As a parent struggling to understand the medical information, I wanted to post what I've learned thus far and I hope it will be of use to you.

 

1) Titers need to be compared to a baseline. Direction is much more important than absolute value.

Some people produce very significant antibody responses, some don't. Some have high baselines, some don't. Since most often there isn't a test result from the prior month to compare against, most doctors (and labs) use a measure known as the "upper limit of normal" [uLN] as defining the baseline for ASO tests. Then if your single sample is > 130%-150% (depends on lab) of this baseline, they consider the test positive.

 

2) So this begs the question of what is the ULN for ASO? There are lots of studies here but what is important is that the studies have a very large range. For example in one study, kids not suspected of GABHS strep in the 5-10 year range, had

• 48% had titers below 100
  
• 6.8% had titers of 100
  
• 10.6% between 101-125
  
• 7.6% between 126-156,
  
• 22.1% between 157-195
  
• and 4.5% in 196-244
  

Unfortunately, even in this study, there didn't seem to be a second measurement taken within 1-2 weeks to look for rise/decline.

 

3) This begs the question of "what level of response consistitutes a positive?." Could a result of <100 still be an indication of a recent strep infection?

The answer appears to be yes, but only if you have a prior value done by the same lab, using the same technique. Most studies show that subjects will have a response 2-4x their baseline, this statistically could still fall within this "normal" range depending on the individual. So again, the importance is to look at trends and not absolute values.

 

4) What about falling titers? Does a high number indicate a current strep infection?

The answer seems to be no. There is just no good study about how fast ASO titers fall and what drives the rate of fall. Thus a single sample really gives no good indication of direction. Most studies agree that the rise is within a week of infection with a peak at 4 weeks, but there isn't a study of whether this peak remains if the initial infection goes untreated. So could someone with an untreated strep infection have a declining ASO titer? -- the answer appears to be yes.

 

For example, the most recent study by Kurlan [June 2008 - Pediatrics] has one subject that has positive throat cultures for 23 of 25 months but the ASO titers are falling within this entire time. What does this mean? No one knows.

 

5) Do all strains of strep produce an ASO reponse?

 

The best study I've found on this is Kaplan's 2003 paper "Immune Response to Group A streptococcal C5a Peptidase in Children: Implications for Vaccine Development." What this paper shows is that despite positive strep cultures on day 1, at a subsequent visit 4 weeks later,

• 46% of subjects presented no ASO rise,
  
• 55% presented no Anti-DNAseB rise,
  
• and 37% presented no rise of either ASO nor Anti-DNAseB
  

There also seems to be good research indicating that skin GABHS infections does not produce ASO response despite producing Streptolysin O.

 

What does this mean?

Does this mean that the test was bad? That some strains don't produce the streptolysin O protein? That some people don't mount a high immune response? That the individual is a strep carrier? That the strep was going on for some time and the ASO titers have already fallen? That skin GABHS infection differs from pharangytis GABHS? The answer is that the scientific community doesn't know. There has been no careful study of the decline rate of ASO titers and the entire field of "strep carriers" is not at all clear.

 

So summarizing,

• a rising ASO titer (regardless of absolute value) is an indication of GABHS strep; however, you need a baseline to be sure it is rising.
  
• A falling ASO titer indicates that there was strep, but no one knows when.
  
• A high ASO titer could be anything including that the titer is falling, rising, or just a high baseline. Statistically it is likely to be a falling titer.
  
• Most will treat a titer of > 400 IU's as a falling titer (i.e., that there was once a strep infection sometime in the past). But the exact time of the infection is not known.
  
• The interpretation of a low ASO titer is unclear. There could have been an infection and the titer has already fallen, the baseline for the person could be low, the individual may not respond with a strong immune response, the strain may not produce significant amounts of streptolysin O.
  

One final comment, Swedo does not require high ASO titers or even rising ASO titers to diagnose PANDAS. The titers are checked only when a positive strep culture is not available and you are retroactively looking for an indication of past infection. The flaw with using titers as an indication of prior strep infection is (as I stated above) that "low" values can still be associated with prior strep infections since the rate of ASO titer decline is not known, most people only have a single sample, and the ASO response is variable across individual and strep type.

 

Regards,

 

Buster