Third Component of Complement (C3) and Fourth Component of Complement (C4) in Discoid and Systemic Lupus erythematosus

Abstract

In 54 patients with lupus erythematosus – 6 with systemic, 19 with disseminated discoid, and 29 with localized discoid lupus erythematosus determination of the 3rd and 4th components of complement (C3 and C4) was performed in a prospective study. In relation to 42 healthy persons, the mean value of C3 proved significantly reduced in systemic lupus erythematosus, and the mean value of C4 was significantly reduced in systemic as well as in disseminated discoid lupus erythematosus. When C3 and C4 were related to disease activity, a depression of complement was found parallel to an increase in disease activity in all three forms of lupus erythematosus. Compared with other serological tests, C3 and C4 afforded the best serological evaluation of the disease activity. Alterations in the clinical condition in 8 of the patients with discoid lupus erythematosus were preceded by changes in C4. A single determination of C4 was diagnostic in 8% of the patients with discoid lupus erythematosus.

Discoid lupus erythematosus and monoclonal gammopathy

“…DLE is not usually associated with any other disease process, although O'Loughlin et al (1978) pointed out that the patients with generalized DLE are more likely to have arthralgias, Raynaud's phenomenon, and fever than are patients with lesions localized to the head and neck. Lupus erythematosus-like skin lesions have been noted in several patients with familial complement deficiency (Osterland, Espinoza & Parker, 1975;Douglass et al, 1976), and significant reduction in C4 has been demonstrated in patients with generalized DLE (Risum, 1973)-OUT patient i, in addition to having a drug-induced Coombs-positive haemolytic anaemia, had total haemolytic complement that was too low to measure, with normal C3 and greatly reduced C4. He had a pronounced and persistent elevation of an IgG / monoclonal protein (more than 3 g/dl), greater than 10",, abnormal plasma cells in the bone marrow, but without progression to anaemia, lytic bone lesions, hypercalcaemia, or renal failure, fulfilling the criteria for 'smouldering' multiple myeloma (Kyle & Grcipp, 1980).…”

Silent lupus nephritis among patients with discoid lupus erythematosus

“…Moreover this could detect "silent lupus nephritis" in this population. In this regard, it should be emphasized that complement consumption as mainly revealed by low C4 was occasionally reportd in DLE (7) as well as DDLE (2,8). On the other hand.…”

Generalized Discoid Lupus Erythematosus With Benign Monoclonal Gammopathy

“…From the clinical and laboratory results, this patient could be classified as displaying generalized DLE or DLE with slight systemic symptoms. The raised ESR, moderate leukopenia, slight anemia, occasional slight fever, decreased complement values in sera and the negative immunoglobulin deposits at the dermoepidermal junction of the normalappearing skin are understandable as signs of g. DLE (1,2,6).…”

“…Generalized or widespread discoid lupus erythematosus (g. DLE) may often show slight or moderate general symptoms, some of which are recognized as the clinical and laboratory findings of systemic lupus erythematosus (SLE). Among these are slight fever, arthralgia, transitory proteinuria, raised erythrocyte sedimentation rate (ESR), positive antinuclear factor (ANF), leukopenia, and decreased serum complement (1)(2)(3). Therefore in some cases, it may be very difficult to differentiate g. DLEfrom SLE.…”