Complement haemolytic activity, circulating immune complexes and the morbidity of sickle cell anaemia

• Published in: APMIS : acta pathologica, microbiologica et immunologica Scandinavica Vol. 107; no. 7-12; pp. 699 - 702
• Main Authors: Anyaegbu, C. C., Okpala, I. E., Aken'Ova, A. Y., Salimonu, L. S.
• Format: Journal Article
• Language: English
• Published: Oxford, UK Blackwell Publishing Ltd 01.07.1999; Blackwell
• Subjects: Adolescent; Adult; Anemia, Sickle Cell - epidemiology; Anemia, Sickle Cell - immunology; Anemias. Hemoglobinopathies; Antigen-Antibody Complex - immunology; Biological and medical sciences; complement; Complement C3 - immunology; Complement C4 - immunology; Complement Factor B - immunology; Diseases of red blood cells; Female; Hematologic and hematopoietic diseases; Hemolysis; Humans; immune complex; Male; Medical sciences; Morbidity; Sickle; Human; Hemoglobinopathy; Sickle cell anemia; Immune response; Serine endopeptidases; Enzyme; Complement C3; Complement C4; Hemopathy; Genetic disease; Crisis; Peptidases; Hemolytic anemia; Complement Factor B; Hydrolases; Complication; Immune complex
• ISSN: 0903-4641; 1600-0463
• DOI: 10.1111/j.1699-0463.1999.tb01463.x

The aim of this study was to find out if the number of crises and complications of sickle cell anaemia (SCA) relate to complement function, or the levels of circulating immune complexes (CIC), complement factor B (Bf), C3 and C4. In 73 steady‐state HbSS patients and 50 HbAA control subjects, we determined the haemolytic activity of the alternative pathway of complement (AP50), of the classical pathway (CH50); and the serum concentrations of Bf, C3, C4 and CIC. By clinical examination of each patient and review of the medical records, we determined the number of complications of SCA which had occurred and the mean number of crises per year over a minimum period of 3 years. The mean±SD AP50 for the patients (14±2 U/ml) was significantly lower than the control value of 16±3 U/ml (p<0.001). AP50 had a significant inverse correlation with the number of crises (r=‐0.30, p<0.02). Mean±SD CIC in patients (0.45±0.38 g/1) was significantly higher than in controls: 0.24±0.15 g/1 (p<0.002). CIC snowed a significant direct correlation with the number of complications of SCA (r=+0.28, p<0.02). Mean±SD Bf in SCA patients (0.19±0.09) was higher than in controls (0.17±0.05). The difference reached marginal statistical significance (p=0.049). SCA patients and controls had no significant differences in CH50, C3 and C4. These parameters and Bf did not correlate with either the number of crises or complications. The mechanisms underlying the correlations observed in this study are yet to be fully elucidated.