ANTIBODY TO C(1)OVER-BAR-INHIBITOR IN A PATIENT RECEIVING C(1)OVER-BAR-INHIBITOR INFUSIONS FOR TREATMENT OF HEREDITARY ANGIONEUROTIC-EDEMA WITH SYSTEMIC LUPUS-ERYTHEMATOSUS REACTS WITH A NORMAL ALLOTYPE OF RESIDUE-458 OF C(1)OVER-BAR-INHIBITOR

Patients with hereditary C4 deficiency are likely to have severe lupus erythematosus. A patient with hereditary angioneurotic edema (HANE) a nd systemic lupus erythematosus (SLE) had a chronic deficiency in C4 b ecause the hereditary deficiency in <C(1)over bar -inhibitor> allowed the C1 in her serum to become activated and then inactivate C4. An att empt was made to repair the Cb deficiency as well as the deficiency in <C(1)over bar -inhibitor> by giving infusions of human <C(1)over bar -inhibitor> in the hope of inducing remissions of both HANE and SLE. D uring treatment, antibody to <C(1)over bar -inhibitor> developed in th e patient; this cleared when the Infusions were stopped. During subseq uent treatment with danazol alone, measurable <C(1)over bar -inhibitor > developed in the patient's serum, but levels of C4 were never signif icantly increased. Antibody to normal <C(1)over bar -inhibitor> was no t expected to develop in the patient because she is heterozygous for t his autosomal dominant trait. A normal allotype (VAL or MET 458), whic h would have been in the preparation used but which the patient does n ot synthesize because she can produce only one allotype (MET 458), app ears to have been immunogenic. The antibody isolated from the patient' s serum reacted with <C(1)over bar -inhibitor> from a normal individua l known to be homozygous for 458-VAL but not with one from a homozygot e for MET-458.