Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:3.4.21.69 (APC)
 16,337 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The cause of the thrombotic tendency in nephrotic patients is unknown. Recent reports of thrombotic complications in patients with deficiencies of protein C or protein S (natural inhibitors of coagulation) have raised the possibility that decreased levels of these proteins may play a role in the hypercoagulable state of nephrotic patients. We measured the levels of protein C, total protein S, and free protein S antigens in 42 patients (21 nephrotic and 21 non-nephrotic) with one of four types of glomerular pathology: diabetic nephropathy (DM), focal glomerular sclerosis (FGS), membranous glomerulonephritis (MGN), and chronic renal failure due to hypertension (CRF). Protein C and total protein S antigen levels were significantly higher in FGS and MGN than they were in DM or CRF. Free protein S levels were lower in DM than they were in MGN. Protein C, total protein S, and free protein S levels did not significantly correlate with either serum albumin or degree of proteinuria. The mean levels of the three proteins did not differ between nephrotic and non-nephrotic patients. Free protein S and protein C were, however, significantly correlated (P less than .005 and P less than .002, respectively) with the type of glomerular pathology, independent of differences in age, sex, serum albumin, or degree of proteinuria. These data suggest that abnormalities of free protein S and protein C are related to the nature of the underlying renal disease, rather than to the degree of proteinuria.
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PMID:Protein S and C antigen levels in proteinuric patients: dependence on type of glomerular pathology. 252 34

C4b-binding protein (C4BP), a regulatory component in the complement system, binds to an anticoagulant vitamin K-dependent plasma protein S (PS) which acts as a cofactor of activated protein C. We raised monoclonal antibodies against C4BP and PS, and developed two different one-step sandwich enzyme immunoassay (EIA) systems for human total C4BP (assay A) and PS-C4BP complex (assay B) by using a solid phase monoclonal antibody and a horseradish peroxidase-labeled monoclonal antibody (Fab'). The reaction time of the assay was 45 min in both EIA systems: 30 min for the immunoreaction and 15 min for the color reaction. The sensitivities were 12 and 20 mg/l in assays A and B, respectively. Linearity was obtained between 31 and 500 mg/l in both EIA systems. Assay A could detect both uncomplexed C4BP and PS-C4BP complex with equal efficiency so that total C4BP level was not affected by PS. The levels of total C4BP and PS-C4BP complex were found to significantly increase in sera from patients with membranous nephropathy and decrease with liver cirrhosis in comparison with the levels in normal subjects. On the other hand, a difference in the total C4BP and PS-C4BP complex levels was not shown between IgA nephropathy and normal subjects. Affinity column analysis and difference of total C4BP and PS-C4BP complex levels showed that most of C4BP in sera exists as PS-C4BP complex.
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PMID:One-step sandwich enzyme immunoassays for human C4b-binding protein (C4BP) and protein S-C4BP complex using monoclonal antibodies. 775 11

We present a patient with membranous glomerulonephritis, several clinical complications of the antiphospholipid syndrome and ulcerative colitis, but without lupus anticoagulant and antiphospholipid/cofactor antibodies. Immunological studies--other antibodies--were negative and failed to show enough criteria for any autoimmune diseases. Evaluation of her laboratory tests for hereditary thrombophilia revealed a heterozygous form of the Leiden mutation that might be associated with widespread vasculopathy. An interesting possibility is that the inherited activated protein C resistance could be an additional risk factor for vaso-occlusive manifestations appearing as a clinical sign of cardiovascular diseases and nephropathy.
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PMID:Membranous glomerulonephritis in a patient with inherited activated protein C resistance. 1130 13