Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UMLS:C0024141 (systemic lupus erythematosus)
 44,322 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

A patient with systemic lupus erythematosus was studied whose blood serum on repeated occasions showed undetectable levels of haemolytic omplement (C). A detailed investigation of individual C components in the serum of the proposita and her family revealed the absence of functional C2 in the patient and half-normal values in the relatives. C4 levels in the family, but not in the patient, were above normal, whereas the levels of factor B were low in all cases. No abnormalities were noted in C3, C9, or C1INH. Tissue typing showed linkage of the C2-deficiency gene with the HLA-A10/B18 and A9/B18 haplotypes. No linkage with red cell antigens and no relationship with plasma kallikrein levels was found.
 ...
PMID:HLA-linked C2 deficiency in a Dutch patient with systemic lupus erythematosus. 46 9

Solubilization of preformed bovine serum albumin (BSA) rabbit anti-BSA complexes in serum with kinetic analysis, haemolytic complement function, complement proteins C1q, C4, C3 and complexes containing C1 inhibitor (C1 INH-C1r-C1s-C1 INH) were serially investigated in relation to disease activity in 25 patients with systemic lupus erythematosus (SLE). Clinical assessment of disease activity was expressed using a validated global index (SLEDAI). Markedly decreased capacity to solubilize immune complexes in serum was mainly found in sever disease. By serial analysis, evidence of fairly persistently impaired classical pathway function was found in most of the patients. In partial contrast, impaired alternative pathway function was more clearly associated with active severe disease. Immune complex solubilization during short incubation (5-10 minutes) correlated with classical and alternative pathway-mediated haemolysis. Solubilization during long incubation (40 minutes) was correlated with haemolytic alternative pathway function. In some patients gradual impairment of solubilization during short incubation, and reduced classical pathway haemolytic activity were detectable 2-4 months before clinical manifestations prompted therapeutical intervention. SLEDAI was negatively correlated with solubilization during prolonged incubation (40 minutes) and with haemolytic alternative pathway function, further emphasizing involvement of the alternative pathway in severe disease. The findings emphasize the importance of impaired complement function due to complement activation in SLE. Assays for immune complex solubilization or other complement functions appear to be useful for monitoring disease activity in SLE.
 ...
PMID:Kinetic analysis of immune complex solubilization: complement function in relation to disease activity in SLE. 158 69

Hereditary angioedema (HAE) is characterized by a deficiency in C1 inhibitor protein (C1 INH) and by clinical symptoms of episodic swelling of subcutaneous or mucosal tissue. It has rarely been reported in association with non-systemic lupus erythematosus (SLE) glomerulonephritis (GN). A recent report of two cases indicates the prognosis to be poor, with both patients progressing to chronic renal failure 8 and 20 years after diagnosis. This report describes the 5-year follow-up of a previously unreported case of an 8-year-old boy with HAE and non-SLE membranoproliferative glomerulonephritis (MPGN). The patient developed macroscopic hematuria, azotemia, and a vasculitic rash. Treatment included prednisone and cyclophosphamide, resulting in clinical improvement. The present report also summarizes the long-term follow-up of three previously reported cases of HAE and non-SLE GN, 25, 16, and 10 years after their initial presentation. Patients monitored for 25 and 16 years had MPGN and normal renal function and received no therapy. The third patient, monitored for 10 years, had segmental MPGN. This patient presented with urinary abnormalities and, after treatment with prednisone, had improvement in her hematuria. None of these four patients developed chronic renal failure. These observations indicate a variable outcome in patients with HAE and non-SLE GN.
 ...
PMID:Long-term follow-up of non-systemic lupus erythematosus glomerulonephritis in patients with hereditary angioedema: report of four cases. 159

C1 activation was assessed in several forms of glomerulonephritis by radioimmunoassay quantitation of circulating (C1INH)2 C1r-C1s complexes (INC). Eight patients with active systemic lupus erythematosus (SLE) and nephritis had elevated serum INC (mean = 15.3 vs control = 5.8, P less than 0.01). Their INC levels were normal during remission. Serum INC had a weak inverse correlation with serum C1q greater than 3 mg/dl (r = 0.42, P = 0.02). In longitudinal studies, serum INC also had a weak inverse correlation with serum C3 and C4. Only 1 of 10 patients with type I and 1 of 15 with type III membrano-proliferative glomerulonephritis (MPGN) had elevated serum INC. No patient with type II MPGN had elevated levels. Two of 10 patients with poststreptococcal glomerulonephritis (P-SGN) had elevated serum INC, but all normalized with convalescence. Patients with IgA nephropathy had normal serum INC. The data demonstrate the importance of C1 activation in SLE and P-SGN. The mechanism of complement activation in types I and III MPGN remains unclear; the data suggest, but do not prove, that C1-independent complement activation may occur in these patients.
 ...
PMID:Quantitation of (C1INH)2 C1r-C1s complexes in glomerulonephritis as an indicator of C1 activation. 302 4

A pedigree of C1 inhibitor (C1 INH) deficiency associated with positive LE cell and an elevated titer of DNA antibodies and antinuclear factor (ANF) and nephropathy was presented. The proband of this family was diagnosed as having definite systemic lupus erythematosus (SLE) after a clinical course of several year since her first visit to our hospital and because of the lack of hemolytic activity of complement (CH50), in spite of the absence of idiopathic edema, C1 INH levels were 1.2 mg/dl (3.8% NHS) determined as antigen and 65 site forming unit (SFU) (5.8% NHS) determined by hemolytic assay in her blood. Her mother and brother had characteristic idiopathic edema of her face, larynx, hand and bowel and they had low levels of C1 INH of 1.8 mg/dl (5.8% NHS) and 4.8 mg/dl (15.5% NHS) respectively in their blood. On the basis of these findings, this family was diagnosed as having a pedigree of hereditary angioneurotic edema (HANE) which is supposedly an inherited autosomal positive trait. Actually, however, the proband's serological and hematological indices became positive and progressed year by year, which implies that SLE was absent for the first several years. It might be said that this interesting clinical course indicates that SLE appeared chronologically as a hereditary deficiency in one of the complement components in this case. In concurrence with the general observation that recurrent viral infections due to the deficiency of complement components are presumed to be responsible for SLE-like disease. Her levels of several kinds of anti-virus antibodies were high. Methylprednisolone helped normalize her level of C1 INH and ameliorate the clinical course.
 ...
PMID:A case of hereditary angioneurotic edema associated with systemic lupus erythematosus. 377 20

Congenital deficit of the inhibitor of C1 esterase (C1 INH) usually presents by oedema of the lower limbs, abdomen and glottis (sometimes lethal), which explains its clinical denomination of angioneurotic oedema. The association of this condition with disseminated lupus erythematosis has been reported in 4 cases and with discoid lupus in 4 cases. Antinuclear factors were found in all these cases but there were only two documented cases of nephropathy (one diffuse proliferative glomerulonephritis and one local glomerulonephritis). The association of a deficit of C1 INH and membrano-proliferative glomerulonephritis has only been reported in 2 cases (one lobular glomerulonephritis and one glomerulonephritis with dense basal membrane deposits). Our case had C1 INH deficiency and proliferative lupic glomerulonephritis in the absence of other clinical and immunological signs of DLE. Nephropathy was not looked for in 9 cases of association of C1 INH deficiency and C3-shearing autoantibody (C3 NEF). A common genetic mechanism for these associations seems very improbable. The aptitude of patients with C1 INH deficiency to synthesise autoantibodies under the influence of infections factors, for example, could explain the higher incidence of lupus and glomerulopathies in these patients.
 ...
PMID:[Hereditary deficiency of C1 esterase inhibitor. Lupus and glomerulonephritis]. 686 19

A dysfunctional C1 inhibitor (C1 INH) from a family in whom the propositus presented with systemic lupus erythematosus but without angioedema previously was shown to have diminished inhibitory activity toward isolated C1r and C1s, and intact C1. The mutation was identified as replacement of Ala443 (P2) with Val. This study further analyzed the reactivity of this mutant and characterized two mutants with Ser or Asp at this position. Ser at P2 does not interfere with binding of target proteases. However, the mutant with Asp at this position is unable to bind C1r and beta factor XIIa, and also has a decreased rate of reaction with C1s and kallikrein. Therefore, alteration of polarity alone had no effect on binding, while a bulky and/or charged side chain was not tolerated. Although defective in inhibition of C1r and C1s, the P2 A-->V mutant had acquired the ability to complex with trypsin. It also completely retained the ability to complex with kallikrein and factor XIIa. None of the 10 individuals expressing this mutant protein has ever had angioedema. This observation, combined with normal inhibition of contact system proteases and defective inhibition of complement proteases, suggests that angioedema is caused by bradykinin generated from contact system activation.
 ...
PMID:Role of the P2 residue of complement 1 inhibitor (Ala443) in determination of target protease specificity: inhibition of complement and contact system proteases. 921 20

The presence of anti-C1-inhibitor (anti-C1-INH) autoantibodies is a hallmark of acquired C1-inhibitor deficiency. However, only scarce data are available on their prevalence, diagnostic value, and/or significance in systemic lupus erythematosus (SLE). In a multicentre study, we determined the levels of autoantibodies to C1-inhibitor in sera from 202 patients with SLE and 134 healthy controls. Additional clinical and laboratory parameters, such as organ involvement, as well as anti-C1q, anti-double-stranded DNA antibody, erythrocyte sedimentation rate, C-reactive protein, C3 and C4 serum complement levels have been studied in patients. The level of anti-C1-INH IgG was significantly higher (p = 0.034) in SLE patients, than in the controls. A high anti-C1-INH level of > or =0.4 U/ml (mean of controls + 2 SD) was found in 17% of the patients, but in only 4% of the controls (p = 0.0003). The SLEDAI score was significantly higher (p = 0.048) and the duration of SLE was significantly longer (p = 0.0004) among patients with elevated anti-C1-INH levels compared with patients without this autoantibody (median disease duration 8 vs. 17 years, respectively). Anti-C1-INH level was not correlated with any other laboratory parameter or organ manifestation of the disease. These findings indicate that the anti-C1-INH level is higher in SLE patients than in healthy controls and furthermore, the anti-C1-INH level correlates with the duration and activity of the disease.
Lupus 2010 Apr
PMID:C1-inhibitor autoantibodies in SLE. 2007 76