Lymphocyte subsets, immunoglobulin levels, complement activity CH50, and phagocytic peroxide production in 19 Iranian patients with first episode of bacterial meningitis

BackgroundDespite the availability of potent antimicrobial drugs, bacterial meningitis remains a serious infection with significant morbidity and mortality. In many studies, pyogenic meningitis is reported in patients with immunoglobulin (Ig) and complement deficiencies. In the present study, a broad range of immunological tests were performed to determine the relative importance of primary immunodeficiency as a predisposing cause of first episode of pyogenic meningitis without any evidence of other major infections in past medical history.MethodsWe studied 19 patients with bacterial meningitis confirmed by smear, culture, and cerebrospinal fluid parameters. Immunological tests were performed within 1 to 21 days of diagnosis. Twenty healthy adults served as controls. Serum Ig levels (IgA, IgG, IgM, IgE) and total hemolytic complement (CH5O) as screening tests were done. Lymphocytes, neutrophils, and T-cells were enumerated. Nitroblue tetrazolium test was used for the assessment of neutrophil function.ResultsThirteen patients were male and six were female. The mean age of the patients was 27.8 ± 19 years (range 5–73 years). One patient had subnormal IgA levels; five patients had subnormal IgE levels; one patient had lymphopenia and low CD4, CD3, and CD19; and one patient had subnormal IgM and IgE levels with lymphopenia and low CD4, CD3, CD8, and CD19 counts. All patients had normal complement components (C3 and C4), CH50, and nitroblue tetrazolium test.ConclusionThe most common immunodeficiency in our study was Ig deficiency. Our results support the recommendation that immunological evaluation, especially Ig assay, should be used in patients with bacterial meningitis even in the first episode.