Tubular and interstitial expression of ICAM-1 as a marker of renal injury in IgA nephropathy

BACKGROUND: The upregulated renal expression of intercellular adhesion molecule 1 (ICAM-1) is associated with glomerular and interstitial infiltration of leukocytes. AIM: To test the hypothesis that renal expression of ICAM-1 may be predictive in the highly variable IgA nephropathy (IgAN). METHODS: ICAM-1 (CD54) in tubular epithelium and interstitial leukocytes, macrophages (CD14), and T cells (CD3) were assessed using avidin-biotin-peroxidase in renal biopsy specimens from 45 patients with IgAN and from 29 patients with no glomerulonephritis. RESULTS: In IgAN, tubular ICAM-1+ was seen in 25 of 45 (55%) biopsy specimens, associated with glomerular hypercellularity, glomerulosclerosis involving less than 50% of the glomerular area, interstitial cellular infiltration, tubular atrophy, and proteinuria (U = 44, p = 0.005). Interstitial ICAM-1+ leukocytes were correlated with glomerulosclerosis involving less and more than 50% of the glomerular area, tubular atrophy, interstitial fibrosis, and serum creatinine concentration (r = 0.6343, p < 0.001). In patients with an increase of 50% in the serum creatinine concentration, interstitial ICAM-1+ leukocytes and CD14+ and CD3+ cells were significantly more numerous than in patients with a stable creatinine concentration. In patients with no glomerulonephritis, tubular ICAM-1+ was seen in 7 of 29 (24%) biopsy specimens, inversely correlated with the number of normal glomeruli and associated with glomerulosclerosis covering more than 50% of the glomerular area, tubular atrophy, and creatinine. CONCLUSIONS: Tubular and interstitial expression of ICAM-1 can be a marker of tubulointerstitial disturbance in IgAN. Interstitial ICAM-1 may be an adverse predictor of disease progression.     

Microarray studies of gene expression in circulating leukocytes in kidney diseases

The molecular characterization of changes in mRNA expression in renal tissue during disease is hampered by the acquisition of sufficient mRNA to do genomewide expression profiling. In many renal diseases, such as systemic lupus erythematosus, IgA nephropathy, antineutrophil cytoplasmic autoantibody (ANCA) associated glomerulonephritis, and small-vessel vasculitis (ANCA disease), circulating leukocytes play a role in onset, progression, and severity of the condition. Circulating leukocytes are readily isolated and supply sufficient mRNA for analysis, allowing molecular investigation into their involvement in the disease process. Our laboratory has undertaken a systematic study of the genomewide expression profiles of the circulating leukocytes from patients with a variety of renal diseases (ANCA disease, IgA nephropathy, lupus nephritis, focal segmental glomerulosclerosis), using the Affymetrix high-density gene chip array technology. Analysis of the data showed clustering of expressed genes unique for each individual disease group. These results imply that significant gene expression changes occur in leukocytes that are circulating in patients with renal diseases. In addition, gene expression has been studied in leukocytes activated in vitro by mechanisms that mimic pathogenic events in vivo. The expression levels of genes identified in in vitro studies were compared with the patient leukocyte gene expression to determine whether similar pathological events were occurring in vivo.     

IgA nephropathy with myeloperoxidase anti-neutrophil cytoplasmic antibodies (MPO ANCA): a discrepancy between the histological activity and MPO ANCA

Anti-neutrophil cytoplasmic antibodies (ANCA) of the immunoglobulin (Ig)G type are associated with rapidly progressive glomerulonephritis. Such antibodies have been detected only rarely in patients with Henoch-Schönlein purpura (HSP) or IgA nephropathy (IgAN). We report a patient with biopsy-proven IgAN with fibrous crescents in whom high titers of IgG ANCA occurred and were confirmed to be anti-myeloperoxidase antibodies (MPO ANCA) by solid-phase enzyme-linked immunosorbent assay (ELISA) and inhibition studies. During a 1-year follow-up period, high titers of MPO ANCA persisted but creatinine clearance remained over 50 ml/min per 1.48 m.² This case suggests the lack of a reliable association between fulminant outcome of IgAN with crescents and high titers of IgG MPO ANCA, and indicates the involvement of subsets of IgG MPO ANCA which recognize important or unimportant epitopes of MPO in the pathogenesis.     

Leukocyte gene expression signatures in antineutrophil cytoplasmic autoantibody and lupus glomerulonephritis

Leukocytes play a major role in the development and progression of autoimmune diseases. We measured gene expression differences in leukocytes from patients that were antineutrophil cytoplasmic autoantibody (ANCA) positive, patients with systemic lupus erythematosus (SLE) or rheumatoid arthritis (RA), and healthy donors to explore potential pathways for clinical intervention. Leukocyte gene expression profiles were determined on Affymetrix U133A/B chips in 88 autoimmune patients, 28 healthy donors, and healthy donor leukocyte cell subtypes that were activated in vitro. Comparison of gene expression in leukocytes identified differentially expressed signature genes that distinguish each donor source. The microarray expression levels for many signature genes correlated with the clinical activity of small vessel vasculitis in the ANCA patients; a result confirmed by quantitative real time-polymerase chain reaction for 16 relevant genes. Comparison with in vitro-activated leukocyte subtypes from healthy donors revealed that the ANCA signature genes were expressed by neutrophils while the SLE signature genes were expressed in activated monocytes and T cells. We have found that leukocyte gene expression data can differentiate patients with RA, SLE, and ANCA-related small vessel vasculitis. Monitoring changes in the expression of specific genes may be a tool to help quantify disease activity during treatment.     

VCAM-1, ICAM-1, and E-selectin in IgA nephropathy and Schönlein-Henoch syndrome: differences between tissue expression and serum concentration

The tissue expressions of vascular cell adhesion molecule 1 (VCAM-1), intercellular adhesion molecule 1 (ICAM-1) and endothelial leukocyte adhesion molecule 1 (E-selectin-1) were investigated in biopsy specimens from 28 patients with different stages of IgA nephropathy (IgAN) and 20 patients with acute renal failure (ARF) or chronic renal diseases (amyloidosis, Alport's glomerulopathy) by immunohistochemistry. The results were compared with the serum levels of the three adhesion molecules. VCAM-1 expression was significantly increased on parietal/tubular epithelial cells in IgAN and ARF. Significantly elevated circulating VCAM-1 levels were measured in IgAN and amyloidosis, but did not correlate with renal function (creatinine clearance). Significantly increased glomerular endothelial/epithelial ICAM-1 expression was found in IgAN and ARF. Intense mesangial ICAM-1 expression was found in mild stages of IgAN and in Sch?nlein-Henoch syndrome. Circulating ICAM-1 was not significantly elevated in IgAN and different renal diseases. VCAM-1 and ICAM-1 expressions of interstitial infiltrating cells were significantly higher in severe than in mild IgAN and associated with an increased infiltration of inflammatory leukocytes. Patients with IgAN and different renal diseases had decreased mesangial and almost absent interstitial E-selectin expression as compared with controls. The circulating E-selectin levels were significantly elevated in ARF. In conclusion, the tissue expression of adhesion molecules in IgAN reflects a continuous inflammatory renal activity. However, only increased circulating VCAM-1 serum levels correlated significantly with the histological state of renal inflammation and could be used as a disease marker.     

Lipid peroxidation in IgA nephropathy and the effect of lipo-prostaglandin E1

BACKGROUND: Lipid peroxidation (LPO) plays a role in glomerulonephritis pathogenesis. The role of LPO in IgA nephropathy (IgAN) and the effect of prostaglandin E1 on it, is not determined. METHODS: Levels of malondialdehyde (MDA), superoxide dismutase (SOD) and vitamin E (vitE) were measured in 42 patients with IgAN and in 31 healthy controls. Clinical nephropathy parameters such as daily proteinuria (DP), serum creatinine (Cr) and Cr clearance were obtained. Forty-two IgAN patients were divided into two subgroups according to renal pathology severity. Twenty-one patients with IgAN received lipo-prostaglandin E1 (PGE1) treatment and the other 21 patients received saline as a control. RESULTS: The serum activity of SOD and vitE in IgAN patients was significantly lower than in healthy controls, while the MDA level was higher in the patient groups. DP-related positively to MDA, while it related negatively to SOD and vitE. Cr clearance related negatively to MDA, while it related positively to SOD and vitE. In the moderate pathological group, the MDA level was significantly higher and the SOD activity was lower than in the mild pathological group. The MDA level in the PGE1 treated group was lower than in the control group, but the activity of SOD and vitE did not differ significantly from the control group. DP declined and Cr clearance increased in the PGE1 treated group, while no significant change in serum Cr was noted. CONCLUSIONS: LPO in IgAN was evident and was at least attributed to the decline in antioxidant ability. LPO could play a role in IgAN pathogenesis, and PGE1 is able to ameliorate the LPO in IgAN patients.     

PDGF-B gene single-nucleotide polymorphisms are not predictive for disease onset or progression of IgA nephropathy

BACKGROUND: Few genetic factors have been identified that determine susceptibility to and progression of IgA-nephropathy (IgAN). Given that IgAN is usually characterized by mesangioproliferative glomerulonephritis and that PDGF-B is of central pathophysiological relevance in this process, we analyzed four single-nucleotide polymorphisms (SNPs) of the PDGF-B gene to evaluate a possible association of these SNPs with disease onset and progression, histological grading and responses to ACE inhibitor (ACEi) therapy. METHODS: The total study population consisted of 195 IgAN patients (127 from southern Italy and 68 from northern Germany) and 200 healthy controls (100 from each region). All four SNPs were in Hardy-Weinberg equilibrium and genotype distributions did not differ between patients and controls in either region. RESULTS: SNP distribution in Italian patients reaching end-stage renal disease (n=45) also was not significantly different from patients maintaining a serum creatinine below 1.2 mg/dl (n=60) during 5.6 +/- 5.5 years of follow-up. Furthermore, we failed to detect significant effects of any SNP on the slope of 1/serum creatinine, proteinuria level or the antiproteinuric response to ACEi. Additionally, particular PDGF-B genotypes did not correlate with histological grading using the Lee classification. CONCLUSION: We conclude that none of the four PDGF-B SNPs is related to the onset of IgAN in two different populations and that none of them has a major influence on the course of IgAN.     

Renal interstitial tenascin immunostaining and immune cell infiltration in IgA nephropathy

SUMMARY: Interstitial expression of tenascin and interstitial leucocyte infiltration were examined by an indirect immunoperoxidase method using monoclonal antibodies against tenascin, CD45 (all leucocytes), CD45RO (T cells) and CD68 (monocytes/macrophages) on renal biopsy specimens from 25 patients with mesangial proliferative IgA-positive glomerulonephritis (IgAN). Ten biopsy kidney specimens, which were removed because of renal trauma, were used as the control group. In patients with IgAN, the mean interstitial expression of tenascin was significantly higher than in the control group. Strong tenascin staining was detected in areas with interstitial damage. In patients with IgAN there were positive correlations between the interstitial expression of tenascin and the relative interstitial cortical volume, as well as serum creatinine. In the IgAN patents, a significant increase in the total number of interstitial CD45-immunopositive cells, CD45RO-positive and CD68-positive cells was seen compared with the control group. In patients with IgAN, immunostaining of tenascin did not correlate with the number of T-cells, monocytes/macrophages or all leucocytes in the renal interstitium. These results suggest that in patients with IgAN the interstitial accumulation of tenascin did not depend on the type or the density of interstitial inflammatory infiltrates.     

Anti-neutrophil cytoplasmic antibody-associated glomerulonephritis in children

Two cases of anti-neutrophil cytoplasmic antibody (ANCA)-associated necrotizing and crescentic glomerulonephritis are reported. A 12-year-old girl and a 10-year-old boy presented with polyarthritis, anaemia, haematuria, proteinuria, impaired renal function, anorexia, nausea, marked loss of weight and lethargy. The boy also had a vasculitic rash and anterior uveitis. Both children had diffuse cytoplasmic ANCA identified by indirect immunofluorescence and confirmed by specific enzyme-linked immunosorbent assay. Renal biopsies showed severe focal and segmental necrotizing glomerulonephritis with 100% crescents. They were treated with plasma exchange, prednisolone, cyclophosphamide and heparin. Within 1 month of commencing treatment, both had normal serum creatinine concentrations and ANCA was not detectable. Renal biopsies 6 weeks following commencement of treatment revealed quiescent disease, although up to 40% of glomeruli were sclerosed or had fibrous crescents. Following cessation of cyclophosphamide and heparin after 7 months and reduction in steroid dose, a biopsy at 10 months in the boy revealed quiescent disease, but the girl had recurrent disease associated with reappearance of a low titre of ANCA and small cellular crescents in 20% of the glomeruli. These cases reflect the potential usefulnes of ANCA determination for categorizing paediatric patients, helping in the selection of therapy and as a possible marker of disease activity, similar to the experience in adults.     

Treatment of Immunoglobulin A Nephropathy Recurrence Post–Renal Transplant

Immunoglobulin A nephropathy (IgAN) is the most commonly occurring glomerulonephritis. Recurrence of disease in the transplanted kidney can significantly reduce allograft survival rates. Currently, there is no definitive management plan for IgAN recurrence in a transplant that reduces the rate of decline of allograft function and prolongs time to dialysis or re-transplantation. Herein we present a 48-year-old man who had received a renal transplantation in 2006 following his diagnosis of IgAN. In 2015, the patient was noted to have an elevated blood pressure and proteinuria (urinary protein:creatinine ratio [uPCR] 170 mg/mmol). A transplant biopsy confirmed recurrent IgAN. A year later, he presented with dipstick hematuria, nephrotic-range proteinuria (uPCR 820 mg/mmol), and a serum creatinine of 90 to 140 μmol/L. A second biopsy revealed mesangioproliferative glomerulopathy consistent with crescentic IgAN. An optimal management plan is currently unknown for recurrent crescentic IgAN in the transplanted kidney. We decided to treat this patient with oral cyclophosphamide daily and high-dose prednisolone. The treatment has so far yielded a positive response and managed to preserve allograft function without significant adverse effects for our patient. Our case illustrates the importance of timely biopsies to identify recurrence of disease and highlights an effective therapeutic option for recurrent IgAN with crescent formation in a transplant.     

A typical Wegeners granulomatosis -- but not pauci-immune!

We present a the case of 58-year old man who was admitted to hospital with typical clinical features (bloody nasal discharge, arthralgia, acute kidney injury with a nephritic syndrome) consisting with Wegeners granulomatosis (WG). CT-scan showed pulmonary nodules and antineutrophil cytoplasmatic antibodies (ANCA) were elevated. A kidney biopsy showed a crescentic glomerulonephritis, but not pauci-immune-immune with a histopathological staining of a mesangioproliferative IgA-glomerulonephritis. The patient was put on prednisolone and i.v. cyclophosphamid (CYCLOPS-protocol (1). The anti-proteinase-3 antibody titer decreased and the CT-scan showed decreased activity of Wegener's granulomatosis (BVAS 26 dropped to 2) and the patient`s serum creatinine level was stable. The exact nosological relation of mesangial IgA-nephropathy to WG is still unclear. This case underlines that knowledge of renal histology is essential in the management of patients with renal disease, especially in patients with hematuria and/or proeinuria with positive ANCA.     

A case of MPO ANCA associated glomerulonephritis with interstitial pneumonitis complicated with lung tuberculosis and pericarditis

The main target organs of myeloperoxidase (MPO) antineutrophil cytoplasmic antibodies (ANCA)-related disease are the kidney and lung. This report describes a 71-year-old man with rapidly progressive glomerulonephritis (RPGN) and interstitial pneumonitis associated with MPO ANCA. The patient was admitted to our hospital because of bloody sputum, low grade fever and appetite loss on October, 1998. He was diagnosed as having interstitial pneumonitis from the findings of chest X-ray and CT examinations. Moderate proteinuria and hematuria, renal dysfunction(serum creatinine: 5.6 mg/dl, BUN: 58.0 mg/dl) and positivity for MPO ANCA were noted. He was negative for anti-glomerular antibody and PR3-ANCA. Renal biopsy was performed and revealed crescentic glomerulonephritis without deposition of immunoglobulins. Therefore, the diagnosis of pauci immune type RPGN was made. Pulse therapy with methylprednisolone(1.0 g/day x 3 days) following oral administration of prednisolone (60 mg/day) found marked improvement of renal function maintenance and interstitial pneumonitis, respectively. However, he died because of lung tuberculosis and acute tuberculous pericarditis during treatment with prednisolone. In this case, MPO ANCA might have been directly associated with both RPGN and interstitial pneumonitis. Furthermore, chronic lung disease, such as interstitial pneumonitis, is important as a preceding disease of RPGN. MPO ANCA-related disease is more frequent in aged persons, therefore particular attention should be paid during their treatment with an immunosuppressant.     

Serum cystatin C as an endogenous parameter of the renal function in patients with normal to moderately impaired kidney function

BACKGROUND: Cystatin C is a proteinase inhibitor with a low molecular weight. The serum levels of cystatin C are mainly dependent on glomerular filtration rate (GFR) making cystatin C an endogenous parameter of GFR. The aim of the study was to elucidate the applicability of serum cystatin C as a parameter of GFR in patients with normal to moderately impaired kidney function and to estimate a reference interval for serum cystatin C. PATIENTS AND METHODS: Forty-six patients (25 males and 21 females) aged 22 to 83 years with various kidney diseases and 250 blood donors (164 males and 86 females) aged 19 to 64 years were included. Cystatin C was measured by an automated particle-enhanced nephelometric immunoassay, serum creatinine by an enzymatic and by Jaffé method, urine creatinine by an enzymatic method, and GFR by 99mTc-DTPA clearance. RESULTS: Serum levels ofcystatin C and creatinine showed increments with decreasing values of 99mTc-DTPA clearance and a linear relationship was found between 99mTc-DTPA clearance and l/serum cystatin C, l/serum creatinine (enzymatic method), and creatinine clearance. Comparison of the non-parametric receiver-operating characteristic (ROC) plots for serum cystatin C (area under the curve (AUC) = 0.996; SE = 0.005), serum creatinine (enzymatic method) (AUC = 0.899; SE = 0.044), serum creatinine (Jaffé method) (AUC = 0.870; SE = 0.051), measured creatinine clearance (AUC = 0.959; SE = 0.025), and estimated creatinine clearance (0.950; SE = 0.029) revealed significant differences for serum cystatin C and serum creatinine (enzymatic and Jaffé method) (p values: 0.03 and 0.01). No significant differences were demonstrated between serum cystatin C and measured and estimated creatinine clearance (p value: 0.14 and 0.12). The non-parametric reference interval for serum cystatin C was calculated to be 0.51-1.02 mg/l (median: 0.79 mg/l; range: 0.33 - 1.07 mg/l). CONCLUSION: Serum cystatin C seems to be a better parameter of GFR than serum creatinine in adults with various types of kidney disease with normal to moderately impaired kidney function.     

Crescentic glomerulonephritis in Wegener's granulomatosis: morphology, therapy, outcome

Fourteen patients with Wegener's granulomatosis (WG) and severe renal and extrarenal involvement were studied (serum creatinine on admission 5.8 +/- 3.4 mg/dl). Renal histology showed a necrotizing, crescentic glomerulonephritis in all patients. Despite advanced renal disease on admission cyclophosphamide, steroids (in 13 patients) and plasma exchange (in 9 patients) caused a rapid and sustained improvement of renal function. Four patients required intermittent hemodialysis over a period of one week. After 2 weeks of treatment serum creatinine values below 2 mg/dl (n = 4) indicated a nearly complete recovery of renal function in the long-term follow up (mean serum creatinine achieved after 12 months therapy: 1.1 +/- 0.1 mg/dl (n = 4). Therefore serum creatinine values observed after 2 weeks of therapy, appear to be of prognostic value with regard to renal outcome. No relapse of active WG or progressive renal deterioration was observed during follow-up (22 +/- 13 months) except in one patient with persisting renal impairment. Three patients died (staphylococcus sepsis, intracerebral hemorrhage during hypertensive crisis, pulmonary embolism) during the first two months of therapy. The decline of serum creatinine seemed to be a better indicator of successful therapy than the decrease of anticytoplasmatic antibody (ANCA), erythrocyte sedimentation rate (ESR) and hematuria. On admission ANCA titer neither correlated with serum creatinine, the degree of renal involvement, nor was it of prognostic value. ANCA, serum creatinine and hematuria normalized within 2 to 8 months, whereas ESR and proteinuria remained elevated. Our data indicate a good prognosis of WG even with advanced renal involvement and generalized vasculitis provided aggressive treatment is performed early.     

The role of sulfatides in autoimmunity in children with various glomerular disease]

Previous studies have suggested that autoimmunity to a number of kidney antigens may exist in glomerular disease. Our own work suggested that sulfatide which is one of the major acidic glycolipids of human kidney may be antigenic. Glycolipids were isolated from lipid extract of human kidney using thin-layer chromatography (TLC). As the major acidic glycolipids, sulfatide, CDH-sulfate, GM3, GD3 were identified. Acidic fraction of lipid extract were chromatographed and then tested for antigen by immunostaining. Sera from patients with IgA nephropathy (IgAN) and Henoch-Sch?nlein purpura nephritis (HSPN) contained antibody to the sulfatide of human kidney as determined by the direct binding of antibody to TLC. In addition, we measured the presence of sulfatide antibodies by enzyme linked immunosorbent assay (ELISA) in sera of patients with various glomerular disease: IgAN, HSPN, mesangial proliferative glomerulonephritis, membranoproliferative glomerulonephritis (MPGN), focal and segmental glomeruosclerosis (FSGS), membranous nephropathy (MN), minimal change nephrotic syndrome (MCNS), acute post streptococcal glomerulonephritis (PSAGN), and lupus nephritis (LN). IgM class sulfatide antibody were demonstrated in many cases of them. The incidence of IgA class sulfatide antibody in HSPN and IgAN was significantly high, and also the high incidence of IgG class sulfatide antibody occurred in IgAN. On the other hand, we evaluated cellular hypersensitivity to sulfatide in IgAN, HSPN, and FSGS using an active E-rosette assay. Positive results occurred in IgAN and HSPN. It was suggested that delayed hypersensitivity to sulfatide may generate an autoimmune inflammatory process. It has been reported that laminin binds specifically to sulfatide. Autoimmunity to sulfatide may disturb the laminin binding and consequently interfere with renal function. These results suggested sulfatide antigen may play important role in occurrence and aggravation of glomerular disease.     

Expression of mRNA for functional molecules in urinary sediment in glomerulonephritis

Recent studies have suggested that gene expression studies using urinary sediment might be a non-invasive approach to assessing activity and pathogenesis in glomerulonephritis. However, little information is available regarding the mRNA expression patterns of functional molecules, such as T-bet, GATA-3, FOXP3, and retinoic acid-inducible gene-I (RIG-I), in urinary sediment, from patients with immunocomplex-mediated glomerulonephritis. Fourteen lupus nephritis (LN) patients, 13 IgA nephropathy (IgAN) patients, and 12 healthy controls were enrolled in the study. The mRNA expressions of T-bet, GATA-3, FOXP3 and RIG-I in urinary sediment were measured using real time quantitative polymerase chain reaction. We also studied the expression of RIG-I in kidney tissue specimens obtained from LN and IgAN patients. Significant differences in the expression patterns of GATA-3, FOXP3 and RIG-I, and marginal differences in T-bet expression, were observed between the three study groups. Immunofluorescent staining for RIG-I was observed in the tissue specimens from the LN patients, but not in those from the IgAN patients. The mRNA expression patterns of T-bet, GATA-3, FOXP3 and RIG-I in urinary sediment differ according to diagnostic category. These results suggest that the measurement of these target gene expressions might be a useful, non-invasive method for clinical monitoring and studying of pathogenesis in glomerulonephritis.