[Comparative characteristics of the complement system in patients with C3-glomerulopathy and atypical hemolytic uremic syndrome of chronic course who suffered an acute episode of thrombotic microangiopathy].

AIM: To compare changes in the complement system in C3-glomerulopathy (C3-GP) and atypical hemolytic uremic syndrome (aHUS) after the relief of an acute episode of thrombotic microangiopathy. MATERIALS AND METHODS: The study included 8 patients diagnosed with C3-GP and 8 with aHUS in remission. The blood levels of the complement system components were determined: C3, C4, C3a, C5a, factor H (CFH), factor B (CFB), membrane-attacking complex (MAC), antibodies to C3b (anti-C3b-AT), the level of hemolytic activity (CH50), the content of factor D (CFD) in the urine. RESULTS: C3 and CH50 levels were within the reference range in both groups, however, in the C3-GP group they were at the lower limit, and C3 level was significantly lower than in the aHUS group: 0.56 [0.44; 0.96] vs 1.37 [1.16; 2.52] (p=0.003). CFB increased level was detected in both groups, but in the C3-GP group it was significantly lower than in the aHUS group - 275.1 [222.1; 356.6] vs 438.7 [323.3; 449.3] (p=0.010). C3a, C5a and MAC levels were increased in both groups, but the maximum was in the C3-GP group, and the MAC level in the C3-GP group was 2 times higher than that in aHUS, and these differences reached statistical significance - 123 555±6686 vs 5603±1294 (p=0.036). CFH and CFD levels was increased in both groups, but their highest values was in the aHUS group. CONCLUSION: Alternative complement pathway activation signs were present in both groups of patients with complement-mediated nephropathies, regardless the stage of the disease. In C3-GP, alternative complement pathway activation was more pronounced than in aHUS after the relief of an acute episode of thrombotic microangiopathy.

[Changes in the complement system in membranoproliferative glomerulonephritis]. / Izmeneniia v sisteme komplementa pri membranoproliferativnom glomerulonefrite.

AIM: To compare the clinical manifestations membranoproliferative glomerulonephritis (MPGN) in its idiopathic variant, lupus nephritis (LN), and C3 glomerulopathy (C3-GP), by comparing them with changes in the complement system. SUBJECTS AND METHODS: The clinic of nephrology followed up 42 patients with different types of MPGN in 2013 to 2015. The study included 35 patients divided into 3 groups: 1) 8 patients with C3-GP, 2) 13 with idiopathic MPGN; 3) 14 with Class IV LN. The investigators studied the blood and urine levels of components and markers for activation of the classical and alternative pathways (C3 and C4, С3а, C5a, CFH, CFB, and CFD) of the terminal complement complex (TCC). RESULTS: The detection rate of C3-GP was 19%. The patients with C3-GP were noted to have the lowest blood concentration of S3 and the highest urinary level of С3а, C5a, TCC, CFH, CFB, and CFD. C3 nephritic factor was detected in 2 patients from the C3-GP (dense deposit disease) group. CONCLUSION: Alternative complement pathway dysregulation caused by genetic or autoimmune factors plays a leading role in the pathogenesis of C3-GP.

[Complement System Abnormalities in Patients with Atypical Hemolytic Uremic Syndrome and Catastrophic Antiphospholipid Syndrome].

Background: The role of the alternative complement pathway (AP) abnormalities in the pathogenesis of aHUS is well studied. Clinical and morphological manifestations of atypical HUS and catastrophic APS are often similar. However, studies on the state of AP in patients with CAPS are virtually absent. Aims: The aim of our study was to assess the state of AP in patients with CAPS and aHUS. Patients and methods: The study enrolled 67 patients (pts) with a diagnosis of CAPS (28 pts) and aHUS (39 pts). Studies of the complement system are made of 10 pts with CAPS and 20 aHUS. Factor H, I, B, D content, functional activity of factor H, and complement components C3, C4 was determined in serum by ELISA kit. Results: Patients with CAPS and aHUS showed similar changes in complement biomarkers. The factor H level in the serum was significantly higher than the standard value. However, the specific activity of factor H reduced, mean rate 59% for aHUS and 26% for CAPS. The median value of factor D was twice higher than the normal range in both groups, indicating the activation of the AP. Conclusions: There are indications of an AP activation not only in pts with aHUS but in CAPS pts too. We suppose that the activity of factor H is a more sensitive indicator of complement system changes than factor H level. Patients with CAPS and aHUS have similar clinical and laboratory characteristics. However, CAPS is more severe, with the involvement of a larger number of vascular beds. Perhaps this is due to the double damaging effects on the endothelium ­ of antiphospholipid antibodies (aPL) and activated complement. So we hypothesize that CAPS can be called aPL-mediated TMA in pts with a complement system defect.

[Anticoagulative and anticomplementary activity of endogenous inhibitor preparation from hepatopancreas of red king crab (Paralithosed camtschaticus) towards human blood].

Serpins (SERine Protease INhibitors)--is large and diverse group of proteins with similar structures, which can inhibit both serine and cysteine proteases by an irreversible suicide mechanism. A novel serpin from hepatopancreas of Red King Crab (Paralithosed camtschaticus) was obtained and was studied its effect on the process of human blood plasma clotting. The investigated serpin shows a noticeable anticoagulative activity, which increases dramatically in the combined action with heparine. Though the inhibitor has almost no effect on thrombin, it inhibits C1s (C1-esterase). We studied the action of the serpin from P. camtschaticus on C1s via its competitive inhibition by C1 inhibitor and the novel enzyme. The calculated inhibition constant of the serpin from P. camtschaticus towards C1s is 2.02 +/- 0.71 M. Unlike C1 inhibitor, the novel serpin from P. camtschaticus doesn't suppress fibrinolysis and at the same time prevents blood clotting. These features may be of interest for medical purposes.

[Influence of serum IgG antibodies to Chlamydia trachomatis on the functional activity of complement components].

The immunoenzyme analysis and the method for the determination of IgG-containing immune complexes, carrying C1q component of the complement, were developed. In human blood sera the functional activity of components C3, complex C1r2s2, the content of C1 inhibitor and complement-activating immune complexes were determined. The comparative analysis of the activity of components C3 and C1r2s2, as well as between the content of C1 inhibitor and the activity of complex C1r2s2 for seropositive and seronegative sera, was made. Pronounced correlation for seropositive sera was observed. In addition, for seropositive sera correlation between an increase in IgG immune complexes and a drop in the functional activity of complex C1r2s2, as well as a drop in the functional activity of complex C1r2s2 and a growth in the titers of IgG antibodies to Chlamydia trachomatis, were established. The decreased functional activity of key complement components, simultaneously with the presence of complement-activating immune complexes and high titers of specific antibodies could be the diagnostic criteria of carrier state.

[Determination of the functional activity, amount of C1 inhibitor, and autoantibodies as a tool for differential diagnosis of angioedema]. / Opredelenie funktsional'noi aktivnosti, kolichestva C1 ingibitora i autotel k nemu kak instrument differentsial'noi diagnostiki otekov.

Aetiology of angioedema (and therefore the scheme of its treatment) can be different. Angioedema may be subdivided into four categories: hereditary and acquired angioedemas, allergies and vasculitis. To establish the reason of the hereditary and acquired form of angioedema analyses of functional activity of complement components, quantities and activity of C1 inhibitor, presence (or absence) autoantibodies to C1 inhibitor allow. Sorption of the puried enzymes of activated subcomponent C1s or plasmin on micropanels allows to connect specifically in cells of plate C1 inhibitor from serum and with the help conjugate of antibodies against C1 inhibitor with a horse-radish peroxidase to determine quantity of connected functionally active C1 inhibitor. Addition of this test-system ELISA system for determination of quantitative contents of C1 inhibitor in serum, and also systems for definition IgG, IgA and IgM autoantibodies against C1 inhibitor finishes creation of a necessary set of methods of differential diagnostics.

[A drop of mink complement kills a mouse]. / Kaplia komplementa norok ubivaet mysh'.

The phenomenon of fast death of mice after parenteral administration of mink serum was explained by high activity of mink complement in particular by unusually high activity of its alternative pathway of activation. The presence of antibodies to mouse erythrocytes in mink serum was necessary precondition for their lysis under action of mink complement by classical and alternative pathways. However, removal of these antibodies resulting in cancellation of hemolysis did not effect toxicity of mink serum for nice in vivo. Partial decomplementization of mink serum zymosan completely prevented death of animals.