What exactly does high Dnase test mean?

[h202]

Hi - I'm new here but have been spending a ton of time reading the forum for the last few weeks as we look like we have a pretty classic PANDAS case.  Some quick background:  Son is 6 years old, ADHD but generally well controlled under medication with good feedback during the first 6 months of kindergarten.  On February 7, we got a call from school - our son was acting like a wild animal, uncontrollable, angry and violent, non responsive, and we needed to pick him up NOW.  We had *never* seen violent behavior before.  Since then, we've had countless similar incidents at school, i spent 3 weeks full time in class with him to no avail, we tried a bunch of different adhd/ssri med combos, all to no avail.  He hasn't attended school in 2 months now.  Over time, behaviors at home also became significant (anger, violence, defiance, obstinance, hyperactivity, lack of focus, separation anxiety, etc).  He has had a tic since infancy where he squeezes his fists and makes a grimaced face for a couple seconds.  This picked up when he was 4-5, but not more than a few times a day for a few seconds.  In October/November, the tic picked up a LOT and he would spend 20 minutes at a time squeezing his fists, grimacing, and making blasting noises. This would happen several times a day, and people started noticing outside the home.  Over xmas holiday, he started doing a throat clearing thing, then a tongue clicking thing in February.  The tongue clicking persists, and the fist clenching is a huge part of his day. Assuming PANDAS, we aren't sure if it started in October (when the tic increased, separation anxiety started, and he had his first ever tantrum in his whole life), or in February (when we got the call from school about the violent behavior).  His diagnosis was delayed, because we had changed his ADHD medication in january.. So when his behavior went crazy in feb, we assumed it was a medication side effect.  It wasn't until we tried a bunch of other adhd meds, and ultimately came back to his original med with no improvement two months later, that  we concluded his overnight behaviors weren't medication induced.  His psychologist (who met him last year when we were confirming ADHD, but otherwise saw no concerns) was ready to diagnose him with ASD two weeks ago, based on newly developed defiance, rigidity, lack of eye contact, anger, etc.  His pediatrician was stumped, and referred us to a psychiatrist.  Psychiatrist was the first to suggest PANDAS.  Pediatrician immediately agreed it was worth pursuing. We did bloodwork for strep and mycoplasma.  Myco was negative.  ASO was 328 (<250 range) and DNase was 1300 (<376 range).  It's hard to remember, but son probably had a sore throat at some point in dec or january.  Based on the bloodwork, his pediatrician started him on augmentin 8 days ago, and a 5 day steroid blast.  The blast was moderately rough (anger and underlying tension), but we felt like the next day he woke up pretty good and feel like the last three days have been markedly improved.  We all came up negative on a strep swab (him too).  

His pediatrician is no expert, but had one patient who was under the care of Dr. Murphy in St. Pete (we are in florida).  We are seeing Dr. Murphy this week.  The ped choose augmentin and prednisone as a best guess first step pending our appointment with Dr. Murphy.  We are so lucky that we were able to address this so quickly.  

So now my specific question:  Son probably was exposed to strep no later than january.  There's no way he's had exposure since then (not attending school).  His DNase numbers are very high (1300).  What does that mean exactly?  Ignoring PANDAS, would you still expect it to be so elevated 3 months after a strep infection?  Does a number that high indicate something besides strep is going on?  Our ped acted like she'd never seen a number that high.  Can someone just explain a little about what a high number means?  I'm interested in devil's advocate position (that a number this high could be totally normal three months after an infection, and not indicative of anything to do with PANDAS), and also the PANDAS view.  Like, do non-PANDAS kids' titers drop within 2 months of infection, and a lingering elevated number means the strep infection is doing something unusual?  Obviously, i will ask dr. murphy but just curious of your views.  

 

[MomWithOCDSon]

To a great extent, the medical science is beyond me.  But as a recall, the actual magnitude of the titer count (whether anti-dnase-b or ASO) matters as some "highs" are, in the end, essentially statistically insignificant while others are truly indicative of something amiss.

My recollection is that the anti-dnase-b titer test measures a strep infection exposure that was at least 4 to 6 weeks in the past; if your son's exposure was 3+ months ago, then the fact that his titer level is still "high" by his doctor's standards would suggest that, potentially, some molecular mimicry has taken place in which the strep has exchanged some molecular material with body tissue, tricking the immune system to continue to produce antibodies to attack the "invader" which is actually "self."  This is my simplistic understanding of what can happen in this autoimmune condition.

For the "devil's advocate" view and some decidedly more scientific responses on these topics, I would drop "anti-dnase-b" and/or "molecular mimicry" into the forum search box and then thumb through the resulting topic threads.  These topics have been discussed in some detail during previous years here, but it's been a while.  And it's fairly complex, at least for someone like me.  But there is a wealth of information here, if you have the time and inclination to dig through it!

Good luck!

 

[bobh]

I agree with MomWithOCDSon that autoimmunity could easily explain lingering titres.  I have  heard that some high readings can stick around longer than a couple of months after supposed infection is over and dealt with - but whether that is a separate thing from the auto-immunity, I don't know.

The devil's advocate would mock molecular mimicry, and that mocking would be hard to refute, as it has not often been "captured in the wild" (i.e. been proven in people), and not for PANDAS.  Rheumatic heart disease is one related example where is has been shown, however.  In other words, the devil's advocate would say "show me" - and as far as I know, this is a theory around PANDAS/PANS, not a well-established certainty.

[Rachel]

The medical community has a hard time believing Molecular Mimicry. However, when you have a child that is not able to stand, walk, has all over body pain, nonstop headache, scalp pain, hoarse voice, vocal tics and a doctor from MAYO suspects postinfectious encephalitis then it's time to figure out what the illness really is. The Cunningham Panel can determine if the antibodies are present but only needs to be done when a child is in a flare in (my personal opinion). My son was diagnosed with Postural Orthostatic Tachycardia Syndrome (POTS) in October 2011. POTS can be caused by a virus. He had mycoplasma walking pneumonia in January 2011. Two years later testing revealed high Igg levels of mycoplasma, HHV6, Parvovirus, and a 500 strep DNASE level. My son suffered with his symptoms for several years and they did not appear overnight. The testing (Cunningham Panel) is available to prove that the antibodies do attach themselves to neural receptors. Thank goodness we have a few doctors that recognize what this illness is but it needs to be called neural receptors autoimmune encephalitis.