Calcium carbonate-enriched cheese to improve nutrition, compliance and phosphorus control in patients on kidney replacement therapy.

BACKGROUND: Patients on renal replacement therapy face many dietary limitations, and cheese is often limited because of its high phosphate content; we have developed cheese with added calcium carbonate (CaCO3) to provide patients with a nutritional opportunity while improving their phosphate control. METHODS: The present double-blind crossover study was aimed to compare the new modified cheese with an equivalent standard product in 16 patients. The increase in inter-dialysis phosphorus (ΔP) and pre-dialysis calcium were used as the primary endpoints for efficacy and safety. RESULTS: The median ΔP (and IQR) was significantly lower with the modified cheese compared with the standard product: 2.5 (1.9-2.9) mg/dL vs. 2.7 (2.2-3.4) mg/dL, respectively (p < 0.02). No difference was observed in pre-dialysis serum calcium levels. CONCLUSIONS: The described modified cheese may represent an interesting means of overcoming some of the dietary limitations in patients on dialysis to help them achieve better nutrition and quality of life.

PTPN22 R620W polymorphism in the ANCA-associated vasculitides.

OBJECTIVES: PTPN22 is involved in T-cell activation and its R620W single-nucleotide polymorphism (SNP) has been shown to predispose to different autoimmune diseases. The aims of this study were to investigate the role of the PTPN22 R620W SNP in conferring susceptibility to the ANCA-associated vasculitides (AAVs), and to explore potential associations between the PTPN22 genotype and the disease manifestations. METHODS: PTPN22 R620W SNP was genotyped in a cohort of 344 AAV patients [143 with granulomatosis with polyangiitis (Wegener's) (GPA), 102 with microscopic polyangiitis (MPA) and 99 with Churg-Strauss syndrome (CSS)] and in 945 healthy controls. RESULTS: The frequency of the minor allele (620W) was significantly higher in GPA patients than in controls [P = 0.005, χ(2 )= 7.858, odds ratio (OR) = 1.91], while no statistically significant association was found with MPA or CSS. Among GPA patients, the 620W allele was particularly enriched in ANCA-positive patients as compared with controls (P = 0.00012, χ(2 )= 14.73, OR = 2.31); a particularly marked association was also found with ENT involvement (P = 0.0071, χ(2 )= 7.258, OR = 1.98), lung involvement (P = 0.0060, χ(2 )= 7.541, OR = 2.07) and skin manifestations of all kinds (P = 0.000047, χ(2 )= 16.567, OR = 3.73). CONCLUSION: The PTPN22 620W allele confers susceptibility to the development of GPA (but not of MPA or CSS), and particularly of its ANCA-positive subset.

Membranous nephropathy in systemic lupus erythematosus: long-term outcome and prognostic factors of 103 patients.

OBJECTIVES: The objective of this study was to evaluate the clinical features, course, outcome, and prognostic indicators in lupus membranous nephritis (LMN) and to compare data of "pure" LMN vs "mixed" forms. METHODS: We retrospectively examined medical records and kidney biopsies of 103 patients with a diagnosis of LMN. RESULTS: Sixty-seven patients had "pure" LMN and 36 had "mixed" forms. Patients with mixed LMN had more frequent nephrotic syndrome (66.6 vs 44.7%, P = 0.05), low C3 (83.3 vs 62.6%, P = 0.05) and C4 (80.5 vs 52.2%, P = 0.005), anti-DNA positivity (86.0 vs 62.6%, P = 0.03), and a tendency toward a lower creatinine clearance (93 ± 29 vs 112 ± 50 mL/min, P = 0.07). Moreover, mixed membranous nephritis had a higher activity and chronicity index (6.5 ± 2.1 vs 1.4 ± 2.03, P = 0.005 and 2.4 ± 1.7 vs 1.4 ± 1.8, P = 0.0001, respectively). Methylprednisolone pulses and immunosuppressive therapy were more often used in patients with mixed forms (86.1 vs 60.6%, P = 0.016 and 83.3 vs 57.5%, P = 0.008, respectively). After a mean follow-up of 156.5 ± 104.5 months, there was no difference in the 2 subgroups concerning the number of patients achieving remission and patient/renal survival (94.5 vs 94.0% and 85.8 vs 86% at 10 years). At multivariate analysis, serum creatinine at presentation (P = 0.0013), chronicity index (P = 0.007), failure of achieving remission (P = 0.000001), and occurrence of nephritic flares (P = 0.00167) were independent predictors of chronic renal insufficiency. CONCLUSIONS: Despite the differences in clinical and histological presentation, a therapy tailored on the grounds of clinical and histological features may reduce the differences in the outcome of white patients with mixed and pure membranous nephritis.

Long-term outcome of renal transplantation in patients with idiopathic membranous glomerulonephritis (MN).

BACKGROUND: Little information is available about the long-term outcome of renal transplanted patients with idiopathic membranous nephropathy (MN). METHODS: The outcomes of 35 first renal transplants performed between 1975 and 2008 in patients with MN were compared with those of 70 controls transplanted in the same period and matched for sex, age and source of donors. RESULTS: The mean post-transplant follow-up was 117 ± 86 months for MN patients and 123 ± 83 months for controls. At 15 years, patient survival was 96% in patients with MN and 88% in the controls (P = ns), while graft survival rates were respectively 40% and 69% (P = 0.06). MN recurred in 12 patients (34%), namely in 4/8 (50%) patients who received the kidney from related living donors and in 8/27 (29.6%) who received the kidney from a deceased donor. Recurrence led to graft failure in six patients, all deceased donor kidney recipients, within 54 ± 33 months. The other six grafts are functioning 134 ± 73 months after transplantation. Patients with recurrence were more frequently females (42% vs 4.3%, P = 0.02). The recurrence occurred earlier (4.8 ± 3.0 vs 45.6 ± 46.9 months, P = 0.05), and there was a trend to develop a higher proteinuria (7.1 ± 5.5 vs 3.67 ± 2.6 g/24 h, P = 0.1) in grafts eventually lost because of recurrence. CONCLUSIONS: The long-term patient survival was similar in renal transplant recipients with MN and in controls. The graft survival was lower in MN patients than in controls, although the difference was at borderline significance. Recurrence occurred in one-third of the patients and caused graft loss in half of them.

Rituximab monotherapy for remission induction of proliferative lupus nephritis flares: description of 3 cases.

BACKGROUND: The efficacy and safety of rituximab when not associated with other immunosuppressive therapy in induction of remission of proliferative lupus nephritis (PLN) has not until now been proven. METHODS: We report on 3 patients with PLN (class IV), 1 with a nephritic flare and 2 with a proteinuric flare (all with nephrotic syndrome (NS)) treated with 3 intravenous methylprednisolone pulses for 3 consecutive days and with rituximab at day 3 and day 18 associated with oral prednisone. At the beginning of the fourth month of therapy, mycophenolate mofetil was combined with prednisone. RESULTS: Three months after the beginning of therapy, renal function improved in the patient with the nephritic flare, and proteinuria fell to within the non-nephrotic range in all 3 patients. At the end of a follow-up of 24 months, the patient with the nephritic flare had normal renal function (serum creatinine from 1.7 to 1 mg/dL) and mild proteinuria (from 6 to 0.7 g/24 hours). The second patient was in complete remission (proteinuria from 5 to 0.127 g/24 hours) 27 months after the beginning of therapy. In the last patient, followed for 10 months, mild proteinuria persisted (from 6.6 to 0.7 g/24 hours). The therapy was well tolerated by all patients. No adverse effects occurred during the follow-up. CONCLUSION: Although our results must be confirmed by larger prospective studies, rituximab associated with methylprednisolone pulses without any other concomitant immunosuppressive drug seems to be effective and safe for induction therapy of severe flares of PLN.

No clear evidence of ACEi efficacy on the progression of chronic kidney disease in children with hypodysplastic nephropathy--report from the ItalKid Project database.

BACKGROUND: Chronic kidney diseases (CKD) tend to progress to end-stage renal failure (ESRF). As it has been demonstrated that angiotensin-converting enzyme inhibitors (ACEi) have a renoprotective effect in adults with proteinuric disease and may be effective in reducing hyperfiltration and proteinuria, they are also frequently used as anti-progression agents in paediatric patients with CKD despite the lack of data confirming their role in the nephropathies peculiar to children. The aim of this study was to investigate whether patients with hypodysplastic CKD (the most common cause of ESRF in children) treated with ACEi show a significantly slower decline in creatinine clearance (Ccr). METHODS: The analysis was based on the information available in the database of the ItalKid Project, a nationwide, population-based registry of chronic renal insufficiency (CRI) in children in Italy. Of the 822 patients with CRI due to hypodysplasia, we selected those who had been continuously treated with ACEi; the control patients were identified from the same diagnostic group and matched for gender, age and baseline Ccr. RESULTS: Progression was analysed as the slope of Ccr in a total of 164 patients: 41 cases and 123 matched controls. There were no significant between-group differences in blood pressure, duration of follow-up or pre-study slope of Ccr (-0.31+/-2.26 vs -0.33+/-3.58 ml/min/1.73 m2/year; P=NS). After an average of 4.9+/-2.3 years, the mean slope of Ccr was 40% lower in the ACEi-treated cases in comparison to controls (-1.08+/-2.08 vs -1.80+/-4.42 ml/min/1.73 m2/year), however, this difference was not statistically significant (P=0.31). CONCLUSIONS: We conclude that ACEi treatment does not significantly modify the naturally progressive course of hypodysplastic nephropathy in children and further studies are necessary before such treatment is routinely proposed for anti-progression purposes in children with CKD.

Human chromosome 21 gene expression atlas in the mouse.

Genome-wide expression analyses have a crucial role in functional genomics. High resolution methods, such as RNA in situ hybridization provide an accurate description of the spatiotemporal distribution of transcripts as well as a three-dimensional 'in vivo' gene expression overview. We set out to analyse systematically the expression patterns of genes from an entire chromosome. We chose human chromosome 21 because of the medical relevance of trisomy 21 (Down's syndrome). Here we show the expression analysis of all identifiable murine orthologues of human chromosome 21 genes (161 out of 178 confirmed human genes) by RNA in situ hybridization on whole mounts and tissue sections, and by polymerase chain reaction with reverse transcription on adult tissues. We observed patterned expression in several tissues including those affected in trisomy 21 phenotypes (that is, central nervous system, heart, gastrointestinal tract, and limbs). Furthermore, statistical analysis suggests the presence of some regions of the chromosome with genes showing either lack of expression or, to a lesser extent, co-expression in specific tissues. This high resolution expression 'atlas' of an entire human chromosome is an important step towards the understanding of gene function and of the pathogenetic mechanisms in Down's syndrome.

Molecular characterization and expression analysis of Mtmr2, mouse homologue of MTMR2, the Myotubularin-related 2 gene, mutated in CMT4B.

Charcot-Marie-Tooth type 4B (CMT4B) is caused by mutations in the myotubularin-related 2 gene, MTMR2, on chromosome 11q22. To date, six loss of function mutations and one missense mutation have been demonstrated in CMT4B patients. It remains to be determined how dysfunction of a ubiquitously expressed phosphatase causes a demyelinating neuropathy. An animal model for CMT4B would provide insights into the pathogenesis of this disorder. We have therefore characterized the mouse homologue of MTMR2 by reconstructing the full-length Mtmr2 cDNA as well as the genomic structure. The 1932 nucleotide open reading frame corresponds to 15 coding exons, spanning a genomic region of approximately 55 kilobases, on mouse chromosome 9 as demonstrated by fluorescence in situ hybridization analysis. A comparison between the mouse and human genes revealed a similar genomic structure, except for the number of alternatively spliced exons in the 5'-untranslated region, two in mouse and three in man. In situ hybridization analysis of mouse embryos showed that Mtmr2 was ubiquitously expressed during organogenesis at E9.5, with some areas of enriched expression. At E14.5, Mtmr2 mRNA was more abundant in the peripheral nervous system, including in dorsal root ganglia and spinal roots.