Deficient activity of the alternative pathway of complement in beta thalassemia major
J. M. Corry, W. C. Marshall, L. A. Guthrie, A. G. Peerless and R. B. Johnston Jr
Patients with thalassemia major suffer frequent and serious infections,
especially after splenectomy. To explore the basis for this susceptibility,
we examined activity of the complement system in sera from 24 patients. All
sera had normal or increased activity of the classic complement pathway.
However, six of the 24 (three with and three without splenectomy) had
abnormal alternative pathway function, and mean alternative pathway
activity was significantly decreased in both splenectomized and
nonsplenectomized patients. Mean concentrations of C3, factor B, properdin,
and immunoglobulins were normal. Defective alternative pathway function,
especially in conjunction with asplenia, could contribute to the propensity
to infection that exists in thalassemia.