Matrix Metalloproteinases and Their Tissue Inhibitors: an Evaluation of Novel Biomarkers in ANCA-Associated Vasculitis

Matrix metalloproteinases (MMPs) and their tissue inhibitors (TIMPs) may play an important role in both inflammation with subsequent fibrosis and in repair and healing in anti-neutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV). We evaluated the circulating levels of MMPs, including pregnancy-associated plasma protein A (PAPP-A), and TIMPs in patients with AAV. PAPP-A, MMP-2, MMP-3, MMP-7, MMP-9, TIMP-1, TIMP-2 and selected parameters were measured in 100 AAV patients (36 patients with active disease and 64 patients in remission) and 34 healthy subjects. The levels of MMP-2, MMP-3, MMP-7, MMP-9, TIMP-1, TIMP-2, and PAPP-A in AAV were all found to be different to those of the controls. The MMP-7 and PAPP-A concentrations were increased in active disease in comparison to the controls (MMP-7: 13 ±.7 vs. 2 ± 0.6 ng/ml, PAPP-A: 14 ± 18 vs. 6.8 ± 2.6 ng/ml, both P < 0.005). The MMP-2 and TIMP-2 levels were increased in remission when compared to the controls (MMP-2: 242 ± 50 ng/ml vs. 212 ± 26 ng /ml, TIMP-2: 82 ± 14 ng/ml vs. 68 ± 93 ng/ml) and to the active AAV (MMP-2: 242 ± 50 vs. 219 ± 54 ng/ml, TIMP-2: 82 ± 14 ng/ml vs. 73 ± 15 ng/ml, all P < 0.005). MMP-3, MMP-7, TIMP-1, and PAPP-A correlated with serum creatinine. The serum levels of MMPs, TIMPs and PAPP-A are all altered in AAV. MMP-2, MMP-7 and TIMP-2 appear to be promising markers in distinguishing active AAV from remission. MMP-3, MMP-7, TIMP-1, and PAPP-A are associated with kidney function in AAV. Further studies are needed to delineate the exact roles of circulating MMPs, TIMPs and PAPP-A in patients with AAV.

Serum hepcidin is increased in ANCA-associated vasculitis and correlates with activity markers

Hepcidin is a key regulator of iron metabolism and plays an important role in many pathologies. It is increased by iron administration and by inflammation, while erythropoiesis downregulates its expression. It decreases iron availability and thus contributes to anemia of chronic diseases. The aim of the study was to measure hepcidin as a marker and pathogenetic factor in ANCA-associated vasculitis (AAV). Hepcidin plasma concentration was measured by the immunological method in 59 patients with AAV and compared to patients with non-vasculitic etiology of chronic kidney disease, patients on hemodialysis (HD), with systemic lupus erythematodes (SLE) and to healthy controls and blood donors, and was correlated with the parameters of iron metabolism, inflammation, activity of the process and kidney function. Hepcidin concentration was increased in patients with AAV, SLE and HD and correlated positively with C-reactive protein, serum ferritin and creatinine, and negatively with hemoglobin and serum transferrin. In active form of AAV it correlated with the clinical scoring system (BVAS). Hepcidin can thus be considered as a pathogenetic factor of anemia in AAV and can be used for evaluation of inflammation in AAV and as an additional marker in active forms of the disease.

Toxocara spp. seronegativity in Czech patients with early form of multiple sclerosis - clinically isolated syndrome

BACKGROUND

Helminth infections were reported to slightly modulate the host immune system response and decrease the risk of an autoimmune disorder, but on the other hand any infection may activate the immune system and trigger autoimmune reaction. In this study, we aimed to measure eosinophil levels and antibodies against Toxocara spp. in patients with clinically isolated syndrome (CIS) and multiple sclerosis (MS).

METHODS

In total, 220 CIS patients and 62 MS patients were examined. Antibodies against Toxocara secretory/excretory antigens (TES) were measured with an ELISA method.

RESULTS

A total of 1,983 measurements of eosinophil levels were performed in CIS patients, out of which 95 results in 21 different patients were above the upper normal limit of the laboratory, but it was mostly only a relative increase. Two patients showed eosinophil levels above 20 % but both of them suffered from severe allergy. None of the CIS patients had any clinical signs of parasitic infections and the serological tests for antibodies against Toxocara were all negative. In all MS patients, eosinophil levels were in normal range. Antibodies against TES were detected in only 1 out of 62 (1.6%) MS patients.

CONCLUSIONS

Based on our results it does not seem that Toxocara infection represents a potential trigger of MS. Nevertheless, our study indirectly confirms the hypothesis that parasitic infection may protect from autoimmunity.

Novel flow cytometric method for the detection of podocalyxin-positive elements in urine of patients with glomerulonephritides - first promising results

Glomerulonephritides together create a heterogenic group of supposedly immunologically mediated diseases of glomeruli. They still belong among the most frequent causes of chronic renal failure. Detection of podocytes in urine might serve as an important marker of glomerulonephritides activity. The aim of this study was to develop a novel flow cytometric method for the detection of podocyte fragments and podocytes in urine and assess its possible use in clinical practice. We placed emphasis on the improvement of pre-analytic phase. To suppress the autofluorescence of the background, blocking solutions and magnetic separation were used. An additional surface marker CD10 (nephrilysin) was used together with routinely used podocalyxin (PCX) in order to achieve better identification of podocytes. Based on the surface marker expression, three different element types were identified in the urine samples: PCX+/CD10+ elements (EL) (supposedly podocytes), PCX-/CD10+ EL (supposedly parietal epithelial cells) and PCX+ EL. We examined a total of 36 patients who underwent renal biopsy (non-glomerular nephropathy, MGN, FSGS, IgAN, AAV and MPGN) and 27 healthy controls. Negative results were found in non-glomerular nephropathy and in MGN. In patients with FSGS and IgAN, the levels of urine elements were slightly increased. The highest levels of all elements were found in AAV and MPGN. Our first results suggest that flow cytometric detection may distinguish between glomerular and nonglomerular diseases and that the levels of urine elements might correlate with the degree of glomerular destruction.

Can adequate treatment influence the postembolization syndrome and cytokine release in patients undergoing iatrogenic renal artery embolization?

The complete renal artery embolization is an alternative to surgical nephrectomy in seriously ill patients. Iatrogenic embolization can be used in many different conditions. Refractory nephrotic syndrome represents a very rare indication for embolization. Complete renal artery embolization has usually been complicated by postembolization syndrome (PES) which is characterized by flank pain and fever. Possible immunologic contribution to the PES leads some authors to the administration of corticosteroids to the patients undergoing embolization. We report here a cohort of 13 patients undergoing complete embolization of total 21 kidneys due to refractory nephrotic syndrome non-responding to the various specific treatment regimes. We treated our patients undergoing renal artery embolization according to special protocol containing combination of antibiotic drugs and corticosteroids (CS) to diminish PES and evaluated its influence to the cytokine production. The incidence of PES was less frequent and milder in comparison with the historical group of patients. Significant decrease in plasma levels of tumor necrosis factor α during first post-embolization day (8.37 pre- vs. 5.74 pg/ml post-embolization, P=0.0002) could partially explain the reduction of PES symptoms. The procedure was not complicated by severe complications and represents an elegant alternative to surgical procedure. The accurate timing of the embolization remains a controversial point in this intervention.