How soon should ASO titers start to drop?

[worriedmommy]

Can anyone tell me how long it takes to start to see a decline in ASO titers? My non-PANDAS son's ASO was 369 & Anti-DNase B was 346 on 5/5/10. He had a 5 day course of Zithromax and a 10 day course of Cephalexin in May. We just got the results of a follow up blood draw and his ASO is 302 & Anti-DNase B is 353. The pediatrician doesn't really know what to make of these titer numbers. My son started complaining of a sore throat last night and today has red spots on his throat. I'm taking him in for a culture tonight. I'm wondering if I should push for abx even if his rapid is negative? Do titers take a long time to fall, or is treatment needed until they're low?

 

(I should mention that we saw Dr. B earlier this month for my PANDAS daughter, and he stressed the importance of clearing all family memebers of strep, which is why I'm so focused on my son's titers. I'm going to call Dr. B on Monday, but would like to start abx ASAP with my son if needed.)

[Mary M]

My dd's titers were rising on abx. Dr K said something about the titers could be high for a while (no time frame beyond a while). I'd start abx if it were my child. We had our whole family tested this week with the intent to start anyone with elevated titers on abx ASAP.

[MomWithOCDSon]

My DS's titers have been climbing, despite being on abx consistently for the last several months. The pediatrician tells me that just being exposed to strep . . . as he undoubtably is at school . . . will cause that to happen, though the abx will prevent him from becoming symptomatic. In PANDAS kids, however, rising titers can sometimes be linked to increased behavioral challenges, so I don't like it, whether he actually "gets strep" or not!

[LNN]

I generally do not refer to the NIMH Pandas site, as it is far from complete in it's explanation of things, but here's an excerpt re: titers

 

 

What exactly is an anti-streptococcal antibody titer?

 

A. The anti-streptococcal antibody titer determines whether there is immunologic evidence of a previous strep. infection. Two different strep. tests are commercially available: the antistrepolysin O (ASO) titer, which rises 3-6 weeks after a strep. infection, and the antistreptococcal DNAase B (AntiDNAse- titer, which rises 6-8 weeks after a strep. infection.

 

Q. What does an elevated anti-streptococcal antibody titer mean? Is this bad for my child?

 

A. An elevated anti-strep. titer (such as ASO or AntiDNAse- means the child has had a strep. infection sometime within the past few months, and his body created antibodies to fight the strep. bacteria. Some children create lots of antibodies and have very high titers (up to 2,000), while others have more modest elevations. The height of the titer elevation doesn’t matter. Further, elevated titers are not a bad thing. They are measuring a normal, healthy response – the production of antibodies to fight off an infection. The antibodies stay in the body for some time after the infection is gone, but the amount of time that the antibodies persist varies greatly between different individuals. Some children have "positive" antibody titers for many months after a single infection.

 

Q. When is a strep. titer considered to be abnormal, or "elevated"?

 

A. The lab at NIH considers strep. titers between 0-400 to be normal. Other labs set the upper limit at 150 or 200. Since each lab measures titers in different ways, it is important to know the range used by the laboratory where the test was done – just ask where they draw the line between negative or positive titers.

 

It is important to note that some grade-school aged children have chronically "elevated" titers. These may actually be in the normal range for that child, as there is a lot of individual variability in titer values. Because of this variability, doctors will often draw a titer when the child is sick, or shortly thereafter, and then draw another titer several weeks later to see if the titer is "rising" – if so, this is strong evidence that the illness was due to strep. (Of course, a less expensive way to make this determination is to take a throat culture at the time that the child is ill.)

 

Q. Should an elevated strep. titer be treated with antibiotics?

 

A. No. Elevated titers indicate that a patient has had a past strep. exposure but the titers can not tell you precisely when the strep. infection occurred. Children may have "positive" titers for many months after one infection. Since these elevated titers are merely a marker of a prior infection and not proof of an ongoing infection it is not appropriate to give antibiotics for elevated titers. Antibiotics are recommended only when a child has a positive rapid strep. test or positive strep. throat culture.

 

I would recommend your own google search for more current info.

[Joan Pandas Mom]

My Son's ASO was 1014 in Mid Oct. Last time I checked about 1 1/2 ago it was down to 572, so it has been 6-7 months and it still isn't below normal. We had IVIG 3 weeks ago. I want to have it checked again soon.