Oxalate nephropathy associated with chronic pancreatitis.

BACKGROUND AND OBJECTIVES: Enteric overabsorption of oxalate may lead to hyperoxaluria and subsequent acute oxalate nephritis (AON). AON related to chronic pancreatitis is a rare and poorly described condition precluding early recognition and treatment. DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS: We collected the clinical characteristics, treatment, and renal outcome of 12 patients with chronic pancreatitis-associated AON followed in four French renal units. RESULTS: Before AON, mild to moderate chronic kidney disease was present in all patients, diabetes mellitus in eight (insulin [n = 6]; oral antidiabetic drugs [n = 2]), and known chronic pancreatitis in only eight. At presentation, pancreas imaging showed gland atrophy/heterogeneity, Wirsung duct dilation, calcification, or pseudocyst. Renal findings consisted of rapidly progressive renal failure with tubulointerstitial profile. Acute modification of glomerular filtration preceded the AON (i.e., diarrhea and diuretics). Increase in urinary oxalate excretion was found in all tested patients and hypocalcemia in nine (<1.5 mmol/L in four patients). Renal biopsy showed diffuse crystal deposits, highly suggestive of oxalate crystals, with tubular necrosis and interstitial inflammatory cell infiltrates. Treatment consisted of pancreatic enzyme supplementation, oral calcium intake, and an oxalate-free diet in all patients and renal replacement therapy in five patients. After a median follow-up of 7 months, three of 12 patients reached end-stage renal disease. CONCLUSION: AON is an under-recognized severe crystal-induced renal disease with features of tubulointerstitial nephritis that may occur in patients with a long history of chronic pancreatitis or reveal the pancreatic disease. Extrinsic triggering factors should be prevented.

Mycobacterial-immune reconstitution inflammatory syndrome: a cause of acute interstitial nephritis during HIV infection.

Kidney injury during HIV infection encompasses a wide variety of disorders, including acute interstitial nephritis. We report a case of acute granulomatous interstitial nephritis related to a mycobacterial-triggered immune reconstitution inflammatory syndrome (IRIS) in an HIV-infected patient. IRIS is an emerging health concern during HIV infection and should be considered in the diagnostic frame of acute renal failure during immune restoration.

Polyneuropathy, organomegaly, endocrinopathy, monoclonal protein, skin changes (POEMS) syndrome refractory to complete serum vascular endothelial growth factor (VEGF) blockade: insights from sequential VEGF monitoring.

Polyneuropathy, organomegaly, endocrinopathy, monoclonal protein, skin changes (POEMS) syndrome is a systemic condition related to plasma cell dyscrasia. Increased vascular permeability is responsible for some of the hallmarks of this disorder that may include renal microangiopathy. Several lines of evidence suggest that vascular endothelial growth factor (VEGF) is central to the pathogenesis of POEMS syndrome. Thus, specifically targeting VEGF over-expression seems to be a promising treatment. Anti-VEGF therapies are yielding conflicting results. We report on a patient with POEMS syndrome treated with bevacizumab, an anti-VEGF monoclonal antibody. Sequential monitoring of serum VEGF showed sustained normalization of serum VEGF levels, without any beneficial effect on the patient's condition. Indications of this treatment should be chosen carefully.

Alpha-interferon therapy for chronic hepatitis C may induce acute allograft rejection in kidney transplant patients with failed allografts.

BACKGROUND: In hepatitis C virus (HCV) positive kidney transplant (KT) patients, the use of alpha-interferon (alphaIFN) is contraindicated due to the risk of acute rejection (AR). Conversely, if these HCV(+) KT patients lose their allograft, re-transplantation might be contemplated provided alphaIFN therapy has been attempted. METHODS: Between 01/01/1989 and 31/12/1994, 261 kidney transplantations were performed; of these 174 were HCV(-) (group I) and 87 were HCV(+) (group II). RESULTS: At last follow-up (2006), in group I, the number of patients with a functioning graft, the number of patients who died with a functioning graft, and the number of patients who lost their graft before or after month (M) 12 were 92 (52.8%), 14 (8%), 20 (11.5%) and 48 (27.7%), respectively. In group II, the corresponding figures were 22 (25.3%; P < 0.0001), 8 (9.1%; ns), 9 (10.3%; ns) and 48 (55.3%; P < 0.0001). In group I, 19 of 48 (39.5%) patients with failed allografts after M12 underwent transplantectomy (TX) compared to 14 of 48 (29%; ns) in group II. In group II, 11 of 48 (23%) patients were offered alphaIFN therapy after their allograft failed: of these, four (36.3%) developed AR during alphaIFN therapy leading to TX. Histology, in addition to chronic allograft lesions, showed acute cellular and vascular lesions. In patients who were not offered alphaIFN therapy, TX was performed less frequently, i.e. in only six cases (16.2%). CONCLUSIONS: We conclude that even alphaIFN-treated KT patients with a failed allograft can experience acute allograft rejection that requires transplantectomy during therapy.

Steroid-responsive nephrotic syndrome in a child with juvenile idiopathic arthritis.

Renal disease is rare in children with juvenile idiopathic arthritis, although a number of associated nephropathies have been described, including mesangial glomerulonephritis. We report the presence of mesangial glomerulonephritis, revealed by a nephrotic syndrome, in a paediatric patient with juvenile idiopathic arthritis. Short-term steroid treatment induced a rapid remission of the nephrotic syndrome, but the presence of anti-nuclear antibodies, 1:320 in a homogeneous pattern, irregular deposits of C1q in a renal biopsy, and a mother with episodes of cutaneous lupus suggested an uncertain renal evolution for this infant.

Leflunomide treatment for polyomavirus BK-associated nephropathy after kidney transplantation.

Polyomavirus-associated nephropathy (PVAN) affects 1-10% of kidney-transplant (KT) patients, with graft failure/loss in approximately 90% of cases. Reducing immunosuppression is the key treatment option, but addition of leflunomide may improve BK Virus (BKV) clearance and graft survival. In a prospective open-labeled study, 12 KT patients with biopsy-proven PVAN were treated with reduced immunosuppression and leflunomide. BKV viremia and graft function were followed. PVAN was diagnosed at 6 months (3-192) post-transplant; median serum creatinine concentration (sCC) was 189 micromol/l (92-265). After 16 months (8-30) of follow-up, the sCC was 150 micromol/l (90-378, NS). Renal function improved in six cases (50%), remained stable in two (16.6%) and deteriorated in four (33.4%), with graft loss in two (17%). Clearance of BKV viremia was observed in five (42%) cases. Side effects included anemia in six cases leading to leflunomide withdrawal in two patients, and mild thrombocytopenia. In KT patients diagnosed with PVAN, leflunomide plus reduced immunosuppression improved graft function in 66.6%, cleared BKV viremia in 42%, and resulted in side effects in 17%. This limited efficacy contrasts with other reports and falls short of expectation. We conclude that active screening, earlier diagnosis and intervention remain the cornerstones of treatment.

Rituximab therapy for acute humoral rejection after kidney transplantation.

A pilot study was performed on eight consecutive renal-transplant (RT) patients presenting with acute humoral rejection (AHR) to assess the efficacy of monoclonal anti-B cell antibodies, such as rituximab (375 mg/m weekly) for 3 to 5 consecutive weeks, in addition to plasma exchange (PE), steroids, mycophenolate mofetil, and tacrolimus. AHR was associated with increased serum creatinine, the appearance of donor-specific alloantibodies (DSA), and the presence of C4d in a transplant biopsy. After a follow-up of 10 months (range 7-23), patient and graft survivals were 100% and 75%, respectively. Renal function improved in six cases in which serum creatinine decreased from 297+/-140 to 156+/-53 micromol/L (P=0.015); graft loss occurred in two cases; and four patients had infectious complications. At last follow-up, DSA had disappeared or decreased in four cases. Rituximab therapy, in addition to PE, might be of benefit for RT patients presenting with AHR.

[Efficiency of rituximab treatment for recurrence of membranous glomerulopathy after renal transplantation]. / Rémission prolongée induite par le rituximab d'une récidive de glomérulonéphrite extramembraneuse.

Idiopathic membranous glomerulonephritis (MGN) is a rare cause of end-stage renal failure, which can lead to chronic hemodialysis. This glomerulopathy can recur after renal transplantation despite immunosuppressive therapy. To date, there is no confirmed therapy for treatment of renal grafts after recurrence of MGN. Herein, we report on a 27-year-old man who underwent cadaveric renal transplantation for MGN in September 2001. At 2 months posttransplant, a renal biopsy showed membranous deposition on immunofluorescence staining evocative of recurrence of MGN. Proteinuria developed progressively and, at one year, was estimated at 7.65 g/24 h, with hypoalbuminemia of 24 g/l. This persisted despite symptomatic treatment with anti-proteinuric agents (enalapril 20 mg/day and irbesartan 75 mg/day) and atorvastatin (10 mg/day). By March 2004, his proteinuria was 11 g/day; therefore, therapy with rituximab (monoclonal anti-CD20) at 375 mg/m(2) weekly was initiated for four consecutive weeks, followed by the same dosage every four months for one year. Biological controls performed two weeks after the fourth infusion of rituximab showed a fall in proteinuria, assessed at 1 g/24 h, with albuminemia of 29 g/l and normalized lipidic results. A renal biopsy performed 6 months after the first infusion was unchanged. Follow-up at 30 months showed consistent remission of membranous nephropathy, demonstrated by a serum creatinine level of 150 mumol/L, microalbuminuria of 107 mg/24 h and normal albuminemia of 43.7 g/l. There were no side effects; in particular, no infectious complications occurred, despite CD19 lymphocytes being still negative after 30 months. Monoclonal CD-20 antibodies have shown efficacy against MGN compared to conventional therapies in native kidneys. It has recently been shown that CD20 mRNA is overexpressed in the renal interstitium in patients suffering from MGN and that the interstitial infiltrates is mainly composed of B-cell lymphocytes in these patients. These data may explain the efficiency of rituximab in these circumstances.

Renal function and histology in kidney transplant patients receiving tacrolimus and sirolimus or mycophenolate mofetil.

OBJECTIVE: The aim of this study was to assess the effects of tacrolimus in combination with either sirolimus (n = 10) or mycophenolate mofetil (n = 7) on renal function and renal histopathologic factors 6 and 12 months after kidney transplantation. MATERIALS AND METHODS: Renal function was assessed by the glomerular filtration rate (as measured by the inulin clearance rate) and by determining renal functional reserve. A renal allograft biopsy was performed at the time of transplantation and 6 and 12 months later. RESULTS: Serum creatinine levels tended to be higher in the sirolimus group 12 months after transplantation. In contrast, inulin clearance and renal functional reserve were similar in both groups 6 and 12 months after transplantation. With respect to histopathologic findings, only mononuclear-cell interstitial inflammation was significantly higher in the sirolimus group than in the mycophenolate mofetil group 12 months after transplantation. However, the progression of tubular atrophy, interstitial fibrosis, and vascular fibrous intimal thickening within the first postoperative year was significantly greater in the sirolimus group. CONCLUSIONS: In the long term, the addition of sirolimus to treatment with tacrolimus in de novo renal transplant patients might more adversely affect renal allograft survival than might the addition of mycophenolate mofetil to tacrolimus therapy.

Long-term results in renal transplant patients with allograft dysfunction after switching from calcineurin inhibitors to sirolimus.

BACKGROUND: Switching from calcineurin inhibitors (CNIs) to sirolimus might improve renal function in chronic renal transplant patients. METHODS: In a prospective study, we assessed long-term efficacy and safety parameters in 43 renal transplant recipients who were switched from a CNI (cyclosporin A, 65%; and tacrolimus, 35%) to sirolimus for either chronic allograft dysfunction (n = 38) or recurrent cutaneous cancers (n = 5). A kidney biopsy was done in 79% of patients prior to conversion, and showed either chronic allograft nephropathy (n = 26) or CNI nephrotoxicity (n = 7). Conversion was either abrupt or progressive, with CNI withdrawal over 3 weeks. All patients also received steroids with or without mycophenolate mofetil or azathioprin. Patient data were recorded at baseline (D0), at 1 (D30) and 6 months (D180), and at 1, 1.5 and 2 years post-conversion. RESULTS: After a mean post-conversion follow-up of 27+/-1.5 months, 58% of the patients were still on sirolimus. The survival of intent to treat patients and grafts was 95.3 and 93%, respectively. Overall, there was significant improvement in renal function, creatinine clearance increasing from 49.4+/-14.9 to 53+/-16.3 ml/min at D30 (P = 0.01), and to 54.7+/-20 ml/min at D180 (P = 0.01). Thereafter, creatinine clearance was not different from baseline, i.e. 54.7+/-21.7, 52.8+/-20 and 51.7+/-20.3 ml/min at years 1, 1.5 and 2, respectively. We divided the patients into two groups: responders (n = 29), those with an increase in creatinine clearance at 6 months post-conversion compared with D0, and non-responders (n = 14), those with a decrease in creatinine clearance at 6 months post-conversion compared with D0. In univariate analysis, factors predictive of response included proteinuria at D0 and the magnitudes of the differences between D30 and D0 for serum creatinine and lactate dehydrogenase. The conversion was associated with (i) significant decreases in serum calcium, phosphorus and uric acid, and in haemoglobin levels; (ii) significant increases in serum alkaline phosphatase, total cholesterol, parathyroid hormone, and the number of patients on statin and recombinant erythropoietin therapies; and (iii) the appearance of de novo proteinuria of >1 g/day in 28% of patients (P < 0.0009), which was >2 g/day in 12% of the entire cohort. Kidney biopsies in 17 patients 2 years after conversion showed the same Banff scores as observed at baseline. We identified three independent predictive factors for a renal response to the switch: absence of proteinuria, presence of antihypertensive therapy at D0 and serum lactate dehydrogenase level at D30. CONCLUSION: Conversion from CNIs to sirolimus in renal transplant patients with chronic allograft nephropathy was associated with improved renal function; however, 33% of the patients developed overt proteinuria.

Evolution of hepatitis C virus quasispecies in renal transplant patients with de novo glomerulonephritis.

Long-term renal allograft survival in kidney transplant recipients infected by hepatitis C virus (HCV) may be influenced by the occurrence of de novo glomerulopathy associated with this virus. Therefore, we studied the evolution of HCV quasispecies in kidney transplant recipients infected by HCV with or without de novo glomerulopathy. The hypervariable region 1 (HVR-1) of the virus envelope was analyzed by cloning and sequencing 20 clones per sample to assess complexity and diversity from six kidney transplant patients who developed de novo glomerulopathy (group I) matched to six kidney transplant recipients without glomerular disease (group II), according to age, time since renal transplantation, and HCV genotype. Two sera were analyzed for each patient: one at the time of renal transplantation and the other at the time of appearance of de novo glomerulopathy, or after a similar duration since transplantation in group II. Overall, there was a significant increase of HCV viremia after the transplantation. This increase did not differ significantly between group I (+0.5 log copies/ml) and group II patients (+1 log copies/ml). The intersample diversity of HCV was similar in the two groups. Complexity and viral diversity were also similar at the time of transplantation. By contrast, complexity, diversity, and the proportion of nonsynonymous substitutions per nonsynonymous site were significantly higher after transplantation in group I patients. Our findings suggest a higher immune response and/or a particular cytokine production in patients developing de novo glomerulopathy rather than a direct effect of HCV on renal cells.