ABSTRACT
30 patients with bronchiectasis, were included in this work to study serum immunoglobulins IgG, IgA, IgM and complement C3 concentration levels, and other immunological markers [C-reactive protein, rheumatoid and antinuclear factors] and also to look for the associated bacterial pathogen. 30 normal individuals were selected as a control group. It was found that 80% of patients had a significant elevation in at least one of immunoglobulin level which was related mainly to the degree of severity of the disease. On the other h and, a nonsignificant change in complement C3 was observed. 60% of the cases were seropositive for C-reactive protein, 33.3% showed positive rheumatoid factor, while 6.6% were seropositive for antinuclear factors. Gram-negative organisms were found in the sputum of 70% of patients. These immunological changes are supposed to be due to persistent antigenic stimulation and hyperimmune responses or the endotoxin of Gram-negative organisms isolated may be of aetiological significance in the development of autoantibodies and elevation of immunoglobulin levels