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Is There a Temporal Relationship Between Outdoor Alternaria alternata Spore Counts and Specific IgE Alternaria alternata Levels?
Saturday, March 5, 2016
South Exhibit Hall H (Convention Center)
Hani Hadi, MD, Jay M. Portnoy, MD FAAAAI, Charles S. Barnes, PhD FAAAAI, Vincent Staggs, PhD
Rationale:

Outdoor spore counts exhibit significant seasonal variation. We hypothesize a temporal relationship between outdoor Alternaria spore levels and measured sIgE levels. 

Methods:

Data on outdoor spore levels were collected for Alternaria alternata between March and November, 1998 to 2012.  Collections were made from a fifth floor rooftop in Kansas City.  Spores were collected with a Burkard device and slides read by NAB certified counters using the 12 traverse method in four hour increments. Patient Alternaria IgE blood levels were retrieved from a clinical laboratory database from January 2000 to September 2012.  IRB approval was obtained.  We looked for a relationship for the time period 2000-2012. Patients with sIgE < 0.35 were excluded. Units of time were defined in weeks.

Data was analyzed using SAS. Average weekly Alternaria counts and IgE results were log-transformed. The logarithmic correlation between average counts and sIgE were computed for the same week up to twelve weeks prior. Twelve weeks was chosen as the cutoff, otherwise one would be in part of the season where measurements for three months would have already been made.

Results:

Correlation between weekly Alternaria spore levels and sIgE levels ranged from -0.009 to +0.205 during the twelve week period. Alternaria counts 2 weeks prior exhibited a significant positive correlation (0.205) with subsequent positive sIgE levels (p <0.001).

Conclusions:

There is a correlation between outdoor Alternaria counts two weeks prior and measured sIgE Alternaria levels.  This correlation may justify more rigorous studies to determine possible association between Alternaria spore counts and sIgE levels.