Selective antibody deficiency and its relation to the IgG2 and IgG3 subclass titers in recurrent respiratory infections

Selective antibody deficiency with normal immunoglobulins [SADNI] may be identified as part of distinct primary or secondary immunodeficiency disorders. The clinical manifestations include recurrent, often severe or prolonged, upper or lower respiratory tract infections. To evaluate SADNI in patients with recurrent sinopulmonary infections and its relation to IgG subclass deficiencies. Methods: In a case-control study, anti-pneumococcal antibody titer and IgG2, IgG3 levels before injection of pneumococcal vaccine and anti-pneumococcal antibody titer at least 4 weeks the vaccination were measured in 46 patients and 54 controls. The results were compared using student's t-test. There was a significant correlation between age and anti-pneumococcal antibody titers before and after vaccination in patients. No significant relation was found between pre and post vaccination pneumococcal antibody titer and IgG2 and IgG3 in cases and controls [p>0.05]. The mean of anti-pneumococcal antibody before and after vaccination were significantly different in cases and controls and were higher in control group [p=0.01, p=0.001, respectively]. Anti-pneumococcal antibody titers in 97.8% of cases and 100% of controls group were normal [>3.4 micro g/ml]. 34.8% of cases and 9.1% of controls had low titers of anti-pneumococcal antibody [<20 micro g/ml] while 18.7% of cases and no controls failed to respond to vaccine. Evaluation of anti-pneumococcal antibody titer in patients with recurrent, chronic and severe respiratory infections with normal immunoglobulin levels seems to be necessary as early diagnosis. Treatment of such a cases could prevent later sequelae such as mastoiditis and bronchiecstasia

Antineutrophil cytoplasmic antibodies in patients with pulmonary tuberculosis

Mycobacterium tuberculosis is a major cause of mortality and morbidity worldwide. Infection with this bacterium is known to induce the development of autoantibodies of which a few are also known to be diagnostic markers for some other diseases. antineutrophil cytoplasmic antibodies [ANCA's] are among those autoantibodies used in clinical setting for diagnosing systemic vasculitic syndromes. Multiple studies investigated ANCA positivity in diseases other than small vessel vasculitis. This study was performed to determine the prevalence of ANCA in pulmonary tuberculosis [TB] which may lead to the false diagnosis of Wegener's granulomatosis [WG] or vice versa. In a case-control study, 32 consecutive smear positive pulmonary TB patients and 32 normal individuals were studied. All cases and controls were screened for ANCA by indirect immunofluorescent assay [IIF], and MPO and PR3 were also tested by ELISA. A prenuclear pattern [P-ANCA] was detected in 25% of the cases and 6.25% of the controls and a cytoplasmic pattern [C-ANCA] was deserved in 3.1% of both the cases and the controls by IIF assay. ANCA specificities tested by ELISA in cases revealed that 75% of the cases had anti-MPO and 12.5% had anti-PR3, while in the in controls, 3.12% had anti-MPO and none had anti-PR3. The positive ANCA significantly correlated with TB [p<0.01]. ANCA's may be observed in both TB and systemic vasculitic syndromes such as WG. Tuberculosis and WG share some clinical features. Therefore, in countries with a high prevalence of TB, one has to distinguish between these two diseases especially when no sign of extrapulmonary involvement is observed