Hereditary complement deficiency and lupus: report of four Tunisian cases.

The aim of the study was to assess the clinical and immunological profile of lupus erythematosus (LE) patients with inherited complement deficiency (ICD). A laboratory-based study was conducted in which all LE patients with hypocomplementemia were included. ICD was assessed by hemolytic and antigenic assays.

Pediatric systemic lupus erythematosus with C1q deficiency.

Hereditary deficiency of each component of the classical pathway is associated with increased susceptibility to lupus erythematosus (LE). Both the severity of the disease and the strength of this association are greatest for homozygous C1q deficiency, which is extremely rare. In fact, more than 90% of all individuals with deficiency of this component have LE.