title: Patients' age and the dynamics of IgM for L. pneumophila sg1.
abstract: METHODS
  The results of IgM L. pneumophila sg1 test in 304 adults and 270 children performed at NIPH-NIH in 2004-2007 were analyzed to determine the effects of patients' age and the interval between collected sera on the results and the interpretation.
  
  
  RESULTS
  Significant difference in the level of IgM, depending on the age of the patients (P0 = 0.0084) was found. Positive results (in total 20.4% of patients) were the most frequently observed in patients aged 19-29 years (42.5%), and the least--in patients 60 y.o. and < 2 y.o. (7%). Average and median levels of IgM in these two groups (+60 y.o. and < 2 y.o.) were similar and significantly different from the results in the other groups. From 44 adults and 33 children > or = 2 sera were collected. There was a significant difference in the interval between collecting the first and second serum sample in adults (mainly 3-5 weeks) and children (mainly 2-4 weeks). Significant increase of IgM levels was observed in children when the interval between 1 and 2 sample didn't exceed 4 weeks, while in adults this change was also observed at > 5 weeks (25% of patients). No significant differences in the analysis of the IgM ratio in children (1.25-14) and adults (1.5-26) was found, but longer persistence of IgM in adults than in children was observed.
  
  
  CONCLUSIONS
  Demonstrated trend of faster decline in the level of IgM among children than in adults indicated that in suspected case of legionellosis in children, the serum sample should be taken up to 4-5 weeks after the onset, and at intervals of 1-2 weeks maximum.
authors.forename: Katarzyna
authors.initials: K
authors.lastname: Pancer
mesh_terms: D000293:Adolescent; D000328:Adult; D000367:Age Factors; D000368:Aged; D000907:Antibodies, Bacterial / Q000097:blood*; D002648:Child; D002675:Child, Preschool; D005260:Female; D006801:Humans; D007075:Immunoglobulin M / Q000097:blood*; D007223:Infant; D016952:Legionella pneumophila / Q000276:immunology*; D007876:Legionellosis / Q000097:blood / Q000276:immunology*; D007877:Legionnaires' Disease / Q000097:blood / Q000276:immunology*; D008297:Male; D008875:Middle Aged; D011044:Poland; D014481:United States; D055815:Young Adult
chemical_list: D000907:Antibodies, Bacterial; D007075:Immunoglobulin M