And the association between MAC and disease activity:
1: Clin Immunol Immunopathol 1995 Mar;74(3):283-8 Related Articles, Books, LinkOut
The value of complement activation products in the assessment of systemic lupus erythematosus flares.
Porcel JM, Ordi J, Castro-Salomo A, Vilardell M, Rodrigo MJ, Gene T, Warburton F, Kraus M, Vergani D.
Department of Immunology, King's College Hospital, London, United Kingdom.
Complement activation products (CAP) have been reported as sensitive markers of disease activity in systemic lupus erythematosus (SLE). We have measured seven parameters of the complement system (C3, C4, factor B, C3a, C4a, iC3b, and the terminal complement complex-TCC-) in 61 SLE patients to study their interrelationship and relative efficacy as diagnostic indicators of lupus activity. Disease activity was judged according to a clinical index (SLEDAI) to be active in 22 and inactive in 39 patients. Subjects with active SLE showed increased levels of C3a, C4a, and TCC compared with those of stable lupus and normal controls, and plasma concentrations of these CAP manifested a positive correlation with disease activity scores. However, values of factor B and iC3b did not correlate with lupus flares. Serum C3 levels were a better reflection of the degree of SLE activity than were C4 levels. The anaphylatoxins were extremely sensitive markers of disease activity but they lacked enough specificity, and iC3b was not at all informative for this purpose. On the whole, TCC concentration was the most useful parameter (77% sensitivity, 80% specificity) to monitor lupus activity, correlating the best with the activity scoring system, and thus offers a better laboratory marker of lupus severity than conventional measurements of complement.
PMID: 7859418 [PubMed - indexed for MEDLINE]
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1: Rheumatology (Oxford) 1999 Oct;38(10):933-40 Related Articles, Books, LinkOut
Complement activation in patients with systemic lupus erythematosus without nephritis.
Mollnes TE, Haga HJ, Brun JG, Nielsen EW, Sjoholm A, Sturfeldt G, Martensson U, Bergh K, Rekvig OP.
Department of Immunology and Transfusion Medicine, Nordland Central Hospital, Bodo, Norway.
OBJECTIVE: To study the association between disease activity and complement activation prospectively in patients with systemic lupus erythematosus (SLE). PATIENTS AND METHODS: Twenty-one SLE patients were examined monthly for 1 yr. Disease activity, autoantibodies, conventional complement tests and the following complement activation products were investigated: C1rs-C1inh complexes, C4bc, Bb, C3a, C3bc, C5a and the terminal SC5b-9 complement complex (TCC). RESULTS: Modest variation in disease activity was noted. None of the patients had nephritis. Flare was observed at 27 visits. Four patients had anti-C1q antibodies in conjunction with modestly low C1q concentrations. The complement parameters were rather constant during the observation period. Slightly to moderately decreased C4 (0.05-0.10 g/l) was found in 10 patients and severely decreased C4 (<0.05 g/l) in seven patients. Decreased C4 was not associated with increased complement activation. Complement activation products were either normal or slightly elevated. TCC was the only activation product correlating significantly with score for disease activity at flare. None of the variables tested predicted flares. CONCLUSION: Complement tests are of limited importance in routine examination of SLE without nephritis, although TCC is suggested to be one of the most sensitive markers for disease activity.
PMID: 10534542 [PubMed - indexed for MEDLINE |
