How fast Do ASO titers come down w/o abx

[Santi]

My son's ASO titers have come down from 984 to 852 in 14 days on low dose Azithro. Its obvious to me that the abx helped. Nevertheless I wonder if they would have come down this much and this fast w/o abx. Does anyone have insight on this? Andrea

[Buster]

Hi Santi,

 

There is no good controlled study on the rate of decline of ASO titers. However, IgG has a half-life of 21-28 days. On the assumption that you got a sample of ~1000 at or near the peak of the ASO response (i.e., 4 weeks post infection) and your body is able to stop the infection (either with or without antibiotics), then the values would be expected to be:

• 840 at one week
  
• 707 at two weeks
  
• 594 at three weeks, etc
  

If the sample was taken before the peak, then the rate of decline will obviously vary.

 

Hope that helps.

 

Buster

 

 

My son's ASO titers have come down from 984 to 852 in 14 days on low dose Azithro. Its obvious to me that the abx helped. Nevertheless I wonder if they would have come down this much and this fast w/o abx. Does anyone have insight on this? Andrea

Edited March 19, 2010 by Buster

[Santi]

My son's ASO titers have come down from 984 to 852 in 14 days on low dose Azithro. Its obvious to me that the abx helped. Nevertheless I wonder if they would have come down this much and this fast w/o abx. Does anyone have insight on this? Andrea

Thanks for this info. I will ponder over it a while. Sounds like it is possible for titers to come down fast naturally. Andrea

[Buster]

My son's ASO titers have come down from 984 to 852 in 14 days on low dose Azithro. Its obvious to me that the abx helped. Nevertheless I wonder if they would have come down this much and this fast w/o abx. Does anyone have insight on this? Andrea

Thanks for this info. I will ponder over it a while. Sounds like it is possible for titers to come down fast naturally. Andrea

 

Let me be more specific. Yes, it is possible for titers to drop quite rapidly with or without antibiotics. Antibiotics slow an infection so the body's immune system can catch up. Antibiotics (especially at low dose) do not "kill" bacteria. Only the immune system kills bacteria. Azith is bacteriostatic which means it prevents replication of bacteria -- it doesn't kill it -- it just slows it down.

 

So as long as you have an intact immune system your ASO will come down. However, for lot of people, they can't quite kill off the bacteria faster than it can replicate. For these folks antibiotics are a life saver (literally).

 

Let me know if there is something deeper in your question -- happy to answer or point you at papers.

 

Buster

Edited March 19, 2010 by Buster

[Santi]

My son's ASO titers have come down from 984 to 852 in 14 days on low dose Azithro. Its obvious to me that the abx helped. Nevertheless I wonder if they would have come down this much and this fast w/o abx. Does anyone have insight on this? Andrea

Thanks for this info. I will ponder over it a while. Sounds like it is possible for titers to come down fast naturally. Andrea

 

Let me be more specific. Yes, it is possible for titers to drop quite rapidly with or without antibiotics. Antibiotics slow an infection so the body's immune system can catch up. Antibiotics (especially at low dose) do not "kill" bacteria. Only the immune system kills bacteria. Azith is bacteriostatic which means it prevents replication of bacteria -- it doesn't kill it -- it just slows it down.

 

So as long as you have an intact immune system your ASO will come down. However, for lot of people, they can't quite kill off the bacteria faster than it can replicate. For these folks antibiotics are a life saver (literally).

 

Let me know if there is something deeper in your question -- happy to answer or point you at papers.

 

Buster

Hi Buster,

 

Thanks for the specifics, I'm a bit slow at this still. My son's behaviors are returning since we took him off abx. I really want to put him back on 500mg Azith.asap But you mention this abx does not kill bacteria but helps immune system ward off bacteria. Am I understanding correctly? I can't wait to get him back on I just want to make the right move. Andrea

[Buster]

My son's behaviors are returning since we took him off abx.

That's not good. If he has PANDAS, then you likely have another source of strep in the house. Go get the family throat cultures.

 

I really want to put him back on 500mg Azith.asap But you mention this abx does not kill bacteria but helps immune system ward off bacteria. Am I understanding correctly?

No, antibiotics do not kill bacteria nor do they "ward off" bacteria. Yup, prophylactic antibiotics do not prevent colonization nor prevent infection. They just slow down both. You must have an intact immune system for prophylaxis to have any effect. By the way, you can't believe how many doctors don't know this.

 

Even while on antibiotics, you can still get strep colonization. However, the antibiotics slow the speed at which the colonization/infection can spread so you body can generally kill off the strep without having to mount a full out assault.

 

This means that there will be some antibody rise but not severe.

 

This is the real problem here, prophylaxis (i.e., preventative use of antibiotics) don't stop an immune reaction, they just minimize how much the body has to create an immune reaction.

 

In PANDAS and Sydenham Chorea, this is thought to be effective because these diseases have three components:

1. the initial strep infection
   
2. the creation of the abnormal antibody by the immune system
   
3. a breach of the blood-brain-barrier -- likely due to inflammation
   

So the antibiotics are likely preventing #3 and minimizing #2 and shortening the window of #1. So if your child has symptoms correlated with streptococcal infections, prophylactic antibiotics will likely minimize the symptoms and minimize the duration and may prevent the response entirely by keeping inflammatory cytokines low so that the blood-brain barrier is not breached.

 

If your child has something other than PANDAS then the above will likely have no effect.

 

Regards,

 

Buster

[CandKRich]

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Edited August 12, 2013 by CandKRich