Antibodies to proteinase-3 and myeloperoxidase in systemic vasculitis

AIM: To investigate occurrence and diagnostic significance of antibodies to proteinase-3 (aPR-3) and myeloperoxidase (aMPO) in systemic vasculitis (SV). MATERIAL AND METHODS: A total of 98 patients with different forms of SV were examined: nonspecific aortoarteritis (NAA, n = 18), nodular polyarteritis (NP, n = 18), Wegener granulomatosis (WG, n = 20), obliterating thrombangiitis (OT, n = 21), and hemorrhagic vasculitis (HV, n = 21). Eight patients with primary antiphospholipid syndrome (PAPS) and 20 donors comprised a control group. aPR-3 and aMPO were detected by solid-phase enzyme immunoassay using kits ORGenTec Diagnostica GmbH. RESULTS: aPR-3 were detected in 1 (5.6%) patient with NP and in 3 (14.3%) patients with HV. aPR-3 were detected in 13 (65%) of 20 patients with WG being significantly more frequent not only vs controls (0%) but in some forms of SV and PAPS (p < 0.05). Mean aPR-3 level in 13 WG patients was significantly higher than in 4 patients (1 with NP and 3 with HV) the sera of whom also contained aPR-3. 84.6% patients with WG had higher concentrations of aPR-3, this is significantly more frequently than in the comparison group. In NP and HV these autoantibodies were encountered in the serum only in moderate or low concentrations in patients with high clinicolaboratory activity of the disease. In WG patients there was no correlation between aPR-3 presence, form of the disease and basic clinical manifestations, but mean values of index of clinical activity of vasculitis were significantly higher in patients with aPR-3 than in those free of them. Concentration of aPR-3 in an active phase of the disease was significantly higher than in patients in remission. Moreover, aPR-3 were detected in 83.3% cases in active vasculitis and in 37.5% patients without it. Detection of aPR-3 in WG group was associated with mean sensitivity and good specificity. In examination of the patients in an active phase specificity rose but sensitivity fell. Optimal results were obtained in estimation of aPR-3 level. Thus, in moderate or high concentration, aPR-3 have good sensitivity and high specificity for diagnosis of WG, in a high titer (> 15 U/ml) they are highly sensitive and specific for this vasculitis. aMPO were detected in 1 of 18 patients with NP, in 1 of 21--with OT, in 3 of 21--with HV and in 2 of 21--with NAA. None patients with WG or PAPS had aMPO. aMPO were detected in NP and HV in high activity of inflammation. Part of the patients had affected kidneys. CONCLUSION: Thus, WG is characterized by the presence and high concentration of aPR-3. In the latter case aPR-3 have high (100%) sensitivity and specificity for diagnosis of WG. Detection of aPR-3 can be used as an additional laboratory test for diagnosis of WG and estimation of its activity.     

Tumor necrosis factor-alpha and kidney damage in rheumatoid arthritis

AIM: To investigate clinical significance of tumor necrosis factor-alpha (TNF-alpha) and kidney damage in patients with rheumatoid arthritis (RA). MATERIAL AND METHODS: 94 patients (84 women and 10 men, mean age 45.2 +/- 11.9 years and the disease duration 7.5 +/- 6.5 years) with RA and 20 donors were examined. In 37(39.4%) and 57(60.6%) patients radiological stages I-II and III-IV, respectively, were determined. TNF-alpha and C-reactive protein (CRP) were measured by ELISA. RESULTS: Serum levels of TNF-alpha in patients with RA appeared significantly higher than in donors (10.9 +/- 22.1 pg/ml vs 0.6 +/- 2.0 pg/ml, p < 0.001). 33 (35.1%) of 94 patients had TNF-alpha levels above 6.6 pg/ml. High serum levels of TNF-alpha correlated significantly with the presence of nephrotic syndrome (r = 0.22, p = 0.03) caused by secondary amyloidosis. There were no correlations between high levels of TNF-alpha and sex, age, disease duration, stages and clinical activity in patients with RA. Positive correlation was found between high levels of TNF-alpha and ESR (r = 0.30, p = 0.003), CRP (r = 0.37, p = 0.0001). CONCLUSION: Thus, TNF-alpha may be involved in pathogenesis of amyloidosis in RA.     

Antibodies to phospholipids and the vascular endothelium in nodular polyarteritis

Clinical significance of antibodies to phospholipids (aPL) and vascular endothelium (aVE) was evaluated in 20 patients (9 women and 11 men aged 36 +/- 10.8 years) with nodular polyarteritis (NP) corresponding to classification criteria of the USA Rheumatology College. Antibodies to cardiolipin (aCL) (IgG and IgM) and to beta 2-glycoprotein (beta 2-GP1) (IgG) were titered by solid-phase enzyme immunoassay. Total serum level of aVE (IgG + IgM + IgA) was measured by solid-phase enzyme immunoassay using Eahy. 926 endothelial hybrydoma cell culture. Anticardiolipin antibodies were detected in 11 (55%) of 20 patients, 3 of these had IgG aCL, 4 IgM aCL, and 4 both antibody isotypes. Serum titers of all aCL were moderate in all cases. No antibodies to beta 2-GP1 were detected in any of the patients. Total serum endothelial activity varied from 0 to 89.7% in patients with NP. Mean aVE level was 24.45 +/- 21.2%, which was significantly higher than in donors (p < 0.001). In 4 (26.7%) of 15 patients with NP total level of aVE surpassed the upper threshold normal value. The presence of aCL directly correlated with the presence of reticular livedo (r = 0.54, p < 0.05), but not with any other clinical laboratory manifestations of the disease, including thrombotic complications (deep thrombosis of lower limb veins, stroke, myocardial infarction), renal involvement, increased erythrocyte sedimentation rate, increased concentrations of von Willebrand factor antigen and C-reactive protein, or angiitis activity. Vascular endothelial antibodies directly correlated with renal involvement (r = 1.00, p < 0.01), distal gangrene of the limb (r = 0.83, p < 0.01), and angiitis activity (r = 0.78, p < 0.001), with high level of von Willebrand factor antigen and increased erythrocyte sedimentation rate (r = 0.66 and r = 0.64, respectively; p < 0.01), but not with aCL (r = 0.43, p > 0.05) of any isotype (aCL IgG r = -0.01; r = 0.34; p < 0.05). All patients with aVE had aCL in the serum (aCL IgG in 1, aCL IgG and IgM in 1, and aCL IgM in 2 patients). The results indicate different significance of a CL and aVE in NP; the mechanisms of realization of their pathogenetic potential are still to be investigated.     

Clinico-immunological aspects of renal lesions in rheumatoid arthritis

The aim of this study was to examine the incidence of different renal lesions in rheumatoid arthritis (RA) and to determine their relationships with the type of previous drug therapy and with the specific features of immune disorders. Ninety four patients, 84 (89.9%) females and 10 (10.6%) males) with RA whose mean age was 45.2 +/- 11.9 years and duration of the disease 7.5 +/- 6.5 years were examined. Most of them had degrees 2 and 3 PA (62.7 and 24.4%, respectively). Systemic manifestations were encountered in 60 (63.8%) patients. Eighty one patients took nonsteroidal antiinflammatory drugs (NSAID) continuously: 18 patients for a year, 32 for 5 years, 14 for 6 to 10 years, and 17 for over 10 years. All the patients underwent clinical, laboratory, and instrumental study of partial functions of the kidney. Immunological study involved solid-phase immunoassay of IgA and IgM rheumatoid factor, von Willebrand factor antigens (WF:Ag), C-reactive protein. The serum concentrations were measured by the Mancini method. Changes in urinalysis and/or signs of decreased glomerular and tubular functions were found in 69 (73.%) patients, 25 (26.6%) had arterial hypertension. Tubular dysfunctions were more common [31 (32.9%) patients]. Signs of early renal failure were detected in 20 (21.2%) patients. There were no cases of acute renal failure. Amyloidosis, glomerulonephritis, pyelonephritis were diagnosed in 5 (5.3%), 16 (17%), and 13 (13.8%) patients, respectively. The above renal lesions were concurrent in some patients. Renal lesion correlated with the progression and severity of RA, the presence of systemic manifestations, and age. There was no relationship of both 5- and 10-year use of NSAID to the symptoms of renal disease. The use of these drugs for over 10 years was concurrent with the signs of chronic renal failure and arterial hypertension. Analyzing immunological disorders showed an association of increased erythrocytic sedimentation rates and WF:Ag with amyloidosis, that of higher IgA concentrations with proteinuria and tubular dysfunctions. It is concluded that renal lesion is common in RA, there is a predominance of tubular interstitial changes. In rare cases nephropathy is characterized by a benign course and fails to result in uremia. The symptoms of renal diseases are largely associated with RA progression and severity and the patients' age. Prolonged continuous use of NSAID may contribute to the development of renal failure. Different immune mechanisms are involved in the pathogenesis of glomerular and tubular nephropathy in RA.