Does the frequency of respiratory tract infections help to identify humoral immunodeficiencies in a primary health-care cohort?
BACKGROUND
Primary immune deficiency (PID) due to humoral defects is associated with recurrent respiratory tract infections (RTIs). Reliable clinical warning signs of PID would facilitate early diagnosis and thereby reduce long-term complications. The aim of the present study was to evaluate the accuracy of the warning sign, 'four or more antibiotic-treated RTIs annually for 3 or more consecutive years,' for detecting PID among adults in a primary health-care setting.


METHODS
Fifty-three cases with 'four or more antibiotic-treated RTIs annually for 3 or more consecutive years' were selected from a Swedish primary health-care registry of RTIs. In addition, 66 age- and sex-matched controls were selected having a maximum of one antibiotic-treated RTI during the period covered by the study. Levels of immunoglobulin (Ig) IgG, IgA, IgM, IgG subclasses, and IgG antibodies against Haemophilus influenzae and Streptococcus pneumoniae as well as the inflammatory markers, C-reactive protein, interleukin (IL)-6 and IL-8 were determined.


RESULTS
IgG subclass deficiencies (IgGsd) were found in 5/53 (9.4%) of the cases and in 7/66 (10.6%) controls. The most frequent deficiency was IgG3sd and this was found in three participants in the case group and seven in the control group. The mean level of IgG3 was lower in the control group (p = 0.02). The mean level of IL-8 was lower in the case group (p = 0.02).


CONCLUSIONS
The results show that physicians working in primary health care cannot solely rely on the frequency of antibiotic-treated RTIs as a warning sign for the detection of common humoral immune deficiencies.
From the Department of Infectious Diseases, Ryhov County Hospital Ryhov , Jönköping.
Per
P
Wågström
Malin
M
Bengnér
Charlotte
C
Dahle
Åsa
Å
Nilsdotter-Augustinsson
Thomas
T
Neumark
Lars
L
Brudin
Janne
J
Björkander
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D016022:Case-Control Studies; D015331:Cohort Studies; D005260:Female; D006801:Humans; D017099:IgG Deficiency / Q000150:complications* / Q000175:diagnosis / Q000453:epidemiology; D056724:Immunity, Humoral; D008297:Male; D008875:Middle Aged; D011320:Primary Health Care; D012141:Respiratory Tract Infections / Q000453:epidemiology / Q000276:immunology*
Clinical warning sign; immunoglobulin deficiency; primary health care; respiratory tract infections