Clinical and immunological studies in a case of selective complete C1q deficiency
Berkel, A.I.; Loos, M.; Sanal, O.; Mauff, G.; Güngen, Y.; Ors, U.; Ersoy, F.; Yegin, O.
Clinical and Experimental Immunology 38(1): 52-63
1979
ISSN/ISBN: 0009-9104 PMID: 527255 Document Number: 150387
A 10-y- old male with recurrent skin lesions and chronic infections had a selective deficiency of Clq [q fragment of complement component 1] after functional analysis of all C components. The aAddition of highly purified human Clq to the patient's serum restored Cl activity, indicating the presence of Clr and Cls and absence of Clq. Titration of highly purified Clq with patient serum as a source of Clr and Cls resulted in a linear dose-response curve. The undetectable CH50 [total hemolytic C] activity temporarily returned to normal within a few hours of plasma infusion, but Cl titers were still only 1-3% of normal. Following plasma administration, the peak of Clq activity was reached after 30 min and returned to undetectable levels within 24 h. The patient serum was not anti-complementary when incubated with normal serum. Nine family members, including the parents and 2 healthy siblings, were subjected to C studies and HLA typing. Cl titers and CH50 activity were normal in all except the paternal grandmother, who showed reduced levels of all C components. There was no linkage for the gene of Clq deficiency and HLA antigens. Among various laboratory studies performed, anti-smooth muscle antibodies, immune complexes and anti-HBsAg [hepatitis B surface antigen] antibody were positive. The child died of a disease compatible with septicemia. Post-mortem tissue studies by light, EM and fluorescent microscopy showed the presence of mesangioproliferative glomerulonephritis.