C1q and systemic lupus erythematosus

In this chapter we review the association between SLE and C1q. In the first part of the chapter we discuss the clinical associations of C1q deficiency, and tabulate the available information in the literature relating to C1q deficiency and autoimmune disease. Other clinical associations of C1q deficiency are then considered, and we mention briefly the association between other genetically determined complement deficiencies and lupus. In the review we explore the relationship between C1q consumption and lupus and we discuss the occurrence of low molecular weight (7S) C1q in lupus, which raises the possibility that increased C1q turnover in the disease may result in unbalanced chain synthesis of the molecule. Anti-C1q antibodies are also strongly associated with severe SLE affecting the kidney, and with hypocomplementaemic urticarial vasculitis, and these associations are also examined. We address the question of how C1q deficiency may cause SLE, discussing the possibility that this may be due to abnormalities of immune complex processing, which have been well characterised in a umber of different human models. There is clear evidence that immune complex processing is abnormal in patients with hypocomplementaemia, and this is compatible with the hypothesis that ineffective immune complex clearance could cause tissue injury, and this may in turn stimulate an autoantibody response. We have also considered the possibility that C1q-C1q receptor interactions are critical in the regulation of apoptosis, and we explore the hypothesis that dysregulation of apoptosis could explain important features in the development of autoimmune disease associated with C1q deficiency. An abnormally high rate of apoptosis, or defective clearance of apoptotic cells, could promote the accumulation of abnormal cellular products that might drive an autoimmune response. Anti-C1q antibodies have been described in a number of murine models of lupus, and these are also briefly discussed. We focus on the recently developed C1q "knockout" mice, which have been developed in our laboratory. Amongst the C1q deficient mice of a mixed genetic background high titres of antinuclear antibodies were detected in approximately half the animals, and around 25% of the mice, aged eight months had evidence of a glomerulonephritis with immune deposits. Large numbers of apoptotic bodies were also present in diseased glomeruli, and this supports the hypothesis that C1q may have a critical role to play in the physiological clearance of apoptotic cells.     

IgG autoantibodies to complement C1q in pediatric-onset systemic lupus erythematosus

The ribosomal internal transcribed spacer (ITS) region from individual Gyrodactylus specimens was amplified by polymerase chain reaction (PCR). The reaction amplified the entire ITS1-5.8S-ITS2 region of the ribosomal RNA gene cluster using primers that hybridize to the 3' terminus of the small subunit and the 5' terminus of the large subunit ribosomal RNA genes. The PCR products from Gyrodactylus salaris and Gyrodactylus thymalli were cloned and sequenced. The Gyrodactylus 5.8S gene was identified following comparative alignment of the G. salaris sequence and a Schistosoma 5.8S gene sequence. The ITS regions from G. salaris, G. thymalli, Gyrodactylus derjavini, and Gyrodactylus truttae were compared by restriction enzyme analysis and interspecific restriction fragment length polymorphisms were found. Gyrodactylus salaris and G. thymalli restriction fragment sizes were confirmed from sequence data. ITS amplification followed by Sau3AI digestion enables rapid and clear differentiation of G. salaris, G. derjavini, and G. truttae.     

Management of systemic lupus erythematosus: Part 1

This is the first of two articles examining the management of systemic lupus erythematosus. This week's article explores the history, aetiology, symptoms and treatment of the disease and next week, the importance of patient education programmes is described.     

Longterm ultraviolet-A1 irradiation therapy in systemic lupus erythematosus

OBJECTIVE: In a recent series of short term studies ultraviolet-A1 (UV-A1; 340-400 nm) dermal irradiation proved effective in reducing signs and symptoms of disease activity in patients with systemic lupus erythematosus (SLE). To determine if the effectiveness persisted with longterm therapy, we followed the progress of 6 of these patients for an average of 3.4 (range 2.4-4.5) yrs. The 6 had had significant decreases in signs and symptoms of disease activity during the first 12 weeks of the earlier studies while receiving 3 to 5 low dose UV-A1 irradiations weekly and were asked to continue into longterm therapy. METHODS: Longterm therapy consisted of 1 or 2 irradiations of 6-15 J/m2 (15-30 min, or about 1/8-1/4 minimal erythema dose) per week. We assessed their progress every 3 mo with the systemic lupus activity measures. RESULTS: Despite the smaller number of weekly treatments, the gains achieved during the initial 12 weeks of the early studies not only persisted but increased slightly. Tanning was moderate to absent, the therapy was well tolerated, and there was no apparent toxicity. CONCLUSION: UV-A1 radiation induced remissions in SLE persist with longterm therapy; 1 or 2 weekly exposures suffice; there appears to be no significant toxicity.     

Recognition and management of systemic lupus erythematosus

Systemic lupus erythematosus (SLE) is an inflammatory systemic disease that causes organ damage by the deposition of autoantibodies and complement activating immune complexes or by vascular occlusion due to procoagulant states associated with antiphospholipid antibodies. The vast majority of cases occur in women of childbearing age. SLE is diagnosed on the basis of its clinical manifestations and the demonstration of characteristic immunological phenomena, especially anti-nuclear antibodies. The prognosis in SLE has shown a distinct improvement over recent decades, the 5-year survival rate now approaching or exceeding 90%. The 15-year survival rate of 63 to 79%, on the other hand, underscores the need for further advances in diagnosis and treatment of the disease. Management of the disease includes regular monitoring of disease activity, avoidance of predisposing factors and close supervision of therapy. Drug therapy is guided by the activity and severity of the leading organ manifestations and ranges from nonsteroidal antirheumatic drugs to intensive treatment with cytotoxic agents. Corticosteroids remain irreplaceable for the control of acute flares. Antimalarials and azathioprine are important long term drugs for treating mild or moderate disease activity. Intravenous pulse cyclophosphamide is safer than other regimens and at least as effective as oral cyclophosphamide for severe lupus nephritis. It is also effective in the treatment of central nervous disease and of other organ-threatening manifestations. Recently, an intensified protocol which included cyclophosphamide induced long term treatment-free remission in 60% of patients. The toxicity of cyclophosphamide is considerable, but can be ameliorated by various measures. The value of several new immunosuppressants and other compounds remains to be determined.     

A case of lupus pancreatitis (?) in systemic lupus erythematosus

An immunochemical method for the quantitative determination of D and E fibrinogen degradation products has been studied; the use of a new type of agarose-gel is suggested, in order to obtain a sensitivity in the nanograms range.     

Hypertension and renal disease in systemic lupus erythematosus

A retrospective analysis of 235 patients at the National Institutes of Health who met at least five criteria for systemic lupus erythematosus (SLE) indicated that 45% were hypertensive. Approximately two thirds of these hypertensive patients had creatinine clearances of more than 60 ml/min and nonnephrotic range proteinuria. Only 16% of normotensive patients had creatinine clearances of less than 60 ml/m9n. A subgroup of 36 patients with SLE and with biopsy-proved diffuse renal disease were studied. For these patients, the presence of hypertension could not be correlated with the degree of proteinuria or hematuria, with the level of serum complement, or with the presence of casts, focal necrosis, crescent formation, or interstitial inflammation. Hypertensive patients had a median age of 24.5 years; the majority had creatinine clearances of more than 60 ml/min. In SLE, hypertension is not necessarily associated with advanced renal disease, and high blood pressure may occur relatively early in the course of the disease.     

Differential expression of CR3, Fc epsilon RII and Fc gamma RIII on polymorphonuclear leukocytes in gingival crevicular fluid

Polymorphonuclear leukocytes (PMNLs) are the most numerous cell population among the cellular infiltrates in gingival crevicular fluid (GCF) and play important roles in the host-defensive system in the gingival crevices. We determined the percentage of neutrophils, eosinophils and basophils in total PMNLs by light microscopic observation using Randolph-methylene blue staining, then assessed flow cytometric differences in the expression of CR3, Fc gamma RIII, Fc epsilon RII, LFA-1 alpha, and LFA-1 beta on PMNL in GCF and peripheral blood (PB) from 21 patients with adult periodontitis (AP) and 13 healthy donors. Percentages of basophils and eosinophils were higher in GCF than in PB. In both AP patients and healthy subjects, expression of CR3 and Fc epsilon RII was higher while Fc gamma RIII was lower in GCF than in PB. The statistical analysis showed that the expressions of Fc gamma RIII and Fc epsilon RII on GCF PMNLs were lower in AP patients than in healthy subjects. Expressions of LFA-1 alpha and beta on GCF were similar to those on PB PMNLs. PB PMNLs stimulated in vitro with Porphyromonas gingivalis culture supernatant and fMLP displayed an expression pattern of CR3, Fc gamma RIII and Fc epsilon RII on GCF PMNLs. However, C5a and IL-1 failed to induce changes in Fc gamma RIII and Fc epsilon RII. The results indicate that GCF neutrophils are activated, present enhanced adhesion and a decreased IgG-binding ability which would reflect that they are at the terminal stage of activation, and that GCF contains a larger eosinophil fraction than in PB. Moreover, these GCF eosinophils appear to be activated.     

Deforming arthropathy or lupus and rhupus hands in systemic lupus erythematosus

OBJECTIVE: Although deforming arthropathy in systemic lupus erythematosus (SLE) is characterised by a number of manifestations, definitive criteria for the different forms have not yet been established. To define deforming arthropathy and its different types a study was undertaken of 176 SLE patients. METHODS: Using as criterion any deviation from any of the metacarpus finger axes 17 patients (16 women, one man) were identified with clinical deforming arthropathy. These patients were evaluated according to a standardised protocol that covered all known characteristics of deforming arthropathy. By means of "Jaccoud's arthropathy index" three different forms were identified. RESULTS: Three patients had an erosive form of deforming arthropathy (or rhupus hand) such as those seen in frank rheumatoid arthritis (RA), eight patients were identified as having Jaccoud's arthropathy (or lupus hand), and the remaining six patients had mild deforming arthropathy. Jaccoud's arthropathy is characterised by severe deformation of the hands (ulnar deviation, swan neck deformities, and Z deformity of the thumb) and feet with multiple non-erosive subluxations, mild aching and little or no evidence of synovitis. All patients, but one, fulfilled just four criteria of the ACR classification and joint symptoms were always found to precede the diagnosis of SLE. Furthermore a remarkable association of Jaccoud's arthropathy with fetal loss, thrombosis--both venous and arterial--and the presence of antiphospholipid antibodies was found. CONCLUSIONS: These data suggest that Jaccoud's arthropathy represents a subset of SLE. Subdivision of deforming arthropathy into several clinical forms can facilitate the clinical management of this disorder.     

Clinical relevance of calreticulin in systemic lupus erythematosus

Calreticulin is an abundant intracellular protein which is proposed to have numerous biological functions. However, there is increasing evidence to suggest that calreticulin plays a multifunctional role as an autoantigen present in patients with systemic lupus erythematosus. In this review we detail some of the recent evidence which indicate that calreticulin may play a supportive role in the formation of the autoantigen complex-Ro/SS-A. In addition, several proposed mechanisms of release and surface expression of calreticulin are described in relation to SLE mediated responses to the autoantigen. In particular, the generation of autoantibodies to specific regions of the protein and the ability of calreticulin to interfere with complement mediated inflammatory processes.     

Immunogenetic bases of systemic lupus erythematosus in humans

INTRODUCTION: Systemic lupus erythematosus (SLE) is an autoimmune disease of unknown pathogenesis. Familial studies and concordance rates among affected twins suggest that human SLE has a strong genetic basis. CURRENT KNOWLEDGE AND KEY POINTS: Recent studies have emphasized that SLE, like other autoimmune diseases, is a complex genetic trait with contributions of both major histocompatibility complex (MHC) associated genes and multiple non-MHC genes. Recent significant advances have been made in the genetic analysis of complex traits, which allow the identification of new candidate genes in SLE. Among the genes reviewed in this article, some polymorphisms of Fc gamma receptor genes and other genes or loci localized on the long arm of the human chromosome 1 appear to be very promising. FUTURE PROSPECTS AND PROJECTS: The identification of new susceptibility genes in SLE will certainly provide important insights into the breakdown of self-tolerance mechanisms leading to autoimmune diseases. To achieve this objective, the recruitment of a large number of genetic traits of multiplex families presenting with SLE is therefore essential. More than 125 multiplex families have been collected to date in France.