Monday, January 30, 2012

Special Needs Kids: Diagnosing Immunodeficiency

by Stefani Bush-from Complex Child emagazine

It’s 3am.  The silence of the room is interrupted by the urgent beeping of the thermometer in your child’s mouth.  No sigh of relief in sight…another fever…another illness…antibiotics aren’t working, and you’re at your wit’s end.  Morning slowly creeps in and you’re on your way to the pediatrician, again.  “This is the third illness in five weeks, this can’t be normal,” you cry.  But your words fall on deaf ears and a laid back response of, “Kids get sick, there’s nothing to worry about.”   Or is there????

A Pattern of Illness

I can’t tell you how many times this scenario played out during my son’s first year.  Typically, my son, Will, would be sick for an average of two to three weeks out of each month, and there was hardly ever more than two weeks between illnesses.  Had I known the warning signs, we would have been able to minimize the frequency and severity of his illnesses, and he would have been able to spend more time laughing and playing like most children his age.

It took determination to prove to our original pediatrician that something WAS wrong.  I obtained all of Will’s medical records, ER records, lab work, and hospitalizations, and graphed them all out.  There was an obvious pattern to his illnesses, and had the pediatrician not brushed them off, it would have saved a lot of time, suffering, and money.

Once we were referred to an immunologist, there was no doubt that Will had some type of Primary Immunodeficiency Disease (also known as PIDD or PI), but figuring out which one was an altogether different story, as there are over 150 different types.  Nevertheless, we were finally on the road to making his life better and that meant the world to us.

When our daughter Sasha was born, she had many health issues, so we moved our care to a new pediatrician’s office.  This pediatrician not only understood immune deficiencies, but he even had a few patients with PIDD.  When Sasha’s illnesses revealed a pattern by three months, there was no hesitation to begin daily preventative antibiotics as a precaution.  When she showed no improvement by nine months, we consulted the same immunologist who was caring for Will.  Treatment began earlier for her because she had a sibling with the disease, we knew what we were looking for, and we were educated about the “warning signs.”

10 Warning Signs of Primary Immunodeficiency Disease

Traditionally, a well known awareness tool used to help identify potential cases of PIDD or PI is the 10 Warning Signs, as noted on the Jeffery Model Foundation’s website:
  1. Four or more new ear infections within 1 year.
  2. Two or more serious sinus infections within 1 year.
  3. Two or more months on antibiotics with little effect.
  4. Two or more pneumonias within 1 year.
  5. Failure of an infant to gain weight or grow normally.
  6. Recurrent, deep skin or organ abscesses.
  7. Persistent thrush in mouth or fungal infection on skin.
  8. Need for intravenous antibiotics to clear infections.
  9. Two or more deep-seated infections including septicemia.
  10. A family history of PI.
However, a recent article published in April 2011 in the journal Pediatrics discusses a study conducted in Europe.1  This study concluded that this standard is too broad, and that specifically family history, sepsis, and failure to thrive are the most important “red flags” that physicians should go by when deciding whether or not to test for PIDD.

While I am not a physician, these results give me great pause.  After researching the article and discussing the study with the Immune Deficiency Foundation (IDF) and medical professionals, there are some key points I’d like to highlight regarding this study.

First of all, the data from this report is not based on American individuals.  The study was conducted in the UK, which has distinctive demographic differences from the US.  Their study population contains a substantial percentage (30%) of individuals whose community has a known high incidence of parental consanguinity (shared bloodlines).  It is therefore reasonable to expect a much higher positive correlation with family history than in our “unrelated” parent population in the US.  This would in turn make family history much more likely to be predictive in the UK than in the US.  A negative family history certainly does not exclude PIDD.   According to IDF surveys, only about 20% of US families report having a family history of the disease.  With some of the more serious disorders associated with a genetic defect, however, the percentage can be somewhat higher.  Family history is important, but can’t be relied upon in most instances.

Secondly, nearly 70% of the more than 150 types of PIDD are antibody or B-cell deficiencies, and most of this article appears to deal with T-lymphocyte, complement and neutrophil deficiencies.  In this case, the recommendations are based on observations that considered only 30% of children with PIDD.  For example, many children with Common Variable Immune Deficiency, one of the most common types of PIDD, may never exhibit symptoms as severe as sepsis or failure to thrive, and thus might be missed by the benchmarks of the study.

Finally, this study was based on patients at pediatric hospitals, which would have excluded many patients whose disease was being managed outside of the hospital setting.  The UK referral system is much more controlled than in the US, with designated tertiary pediatric immunodeficiency centers seeing the bulk of candidate patients for PIDD.  As a result, it is conceivable that patients whose symptoms were less severe might not have been included in the study.

Had Will and Sasha been held to the suggested standard in this particular study, it would have taken a significantly longer period of time to test and diagnose Will because he did not meet any of their three criteria.  Sasha, however, met two of the three criteria almost immediately.

Tracking Infections and IDF Guidelines

The upshot of the above discussion is this:  we need to be aware of disconcerting patterns and characteristics of our children’s illnesses, regardless of what any study suggests.  As such, it is my personal experience that a very useful benchmark is the, “Is it Just An Infection?” set of guidelines set forth by the Immune Deficiency Foundation, which highlights five properties that immunocompromised individuals are likely to display.  Indeed, Will had three of the five initially (and later had four) and Sasha had all of the characterizations listed below:
  • Recurrent: Do the same symptoms keep coming back?
  • Persistent:  Do the symptoms never seem to completely clear?
  • Severe:  Is the infection severe enough to require hospitalization or intravenous antibiotics?
  • Unusual:  Is the infection caused by an uncommon organism?
  • Runs in the Family:  Is there a family history of early infant death or of susceptibility to infection?
As parents, we need to not discount those signs and symptoms that fall outside the realm of normal, but rather be proactive.  If your child exhibits some or all of the properties listed above, alert your pediatrician.

Once you bring this information to the attention of the pediatrician, the next step will be basic diagnostic immune function testing. It is hard to suggest which testing is appropriate given the vast number of PIDDs out there.  There are a variety of different testing approaches a physician might take.  For more information, please see this online publication on testing from IDF.

Don’t Delay the Diagnosis!

Sadly, our story is not unique.  According to the Immune Deficiency Foundation, the time from onset of symptoms to diagnosis averages between 9.2 and 12 years.   While we can’t cure most of the Primary Immunodeficiency Diseases out there, we can still identify them earlier, provide effective treatments, attempt to blunt some of the damage by using preventative therapies, and improve the quality of life for those affected.

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