[Oxalate nephropathy due to malabsorption syndrome]. / Oxalaatnefropathie door malabsorptiesyndromen.

Enteric oxalate nephropathy is caused by hyperoxaluria. Factors which contribute to excessive oxalate absorption are an abundance of free fatty acids in the intestine due to malabsorption, changes in the microbiome, and bowel inflammation. We present two cases that illustrate different pathophysiological aspects of this disease. The first patient was a 70-year-old male who developed oxalate nephropathy through malabsorption caused by chronic pancreatitis. It is plausible that the oxalate nephropathy was set off by antibiotic treatment which influenced the microbiome. The second patient was a 63-year-old male who underwent a Roux-en-Y gastric bypass. The associated malabsorption resulted in oxalate nephropathy. Kidney biopsies from both patients showed typical oxalate crystals. Therapeutic regimens using calcium supplementation, steroids, and a low oxalate diet are rational treatments, which have proven to prevent deterioration of renal function in some patients.

Total Laparoscopic Colocolpopoiesis in a Kidney Transplant Recipient With Frasier Syndrome.

BACKGROUND: The absence of a normal functioning vagina can have a profound impact on women's quality of life and psychological well being. Frasier syndrome is a rare autosomal recessive disorder which presents with male pseudohermaphroditism with gonadal dysgenesis, renal failure in early adulthood and increased risk of developing gonadoblastoma. Kidney transplant recipients are reported to have a high complication rate after colorectal surgery, most probably resulting from immunosuppressive therapy. CASE: A 25-year-old female kidney transplant recipient with Frasier syndrome consulted our department to discuss the possibilities of surgically constructing a functional vagina. She successfully underwent a total laparoscopic colocolpopoiesis without any complications. A sigmoid segment of 16 cm long was isolated laparoscopically and transferred caudally in a dissected pouch between bladder and rectum on its vascular pedicle. There was no short-term morbidity and no complications up to 3 years postoperatively. She experienced no neovaginal symptoms and was able to engage in neovaginal penetration by means of vibrator or neovaginal dilatator. CONCLUSIONS: The positive results in this patient lead us to recommend laparoscopic colocolpopoiesis in kidney transplant patients who are seeking vaginoplasty. We advocate considering a total laparoscopic approach whenever rectosigmoid colocolpopoiesis is indicated, even after a kidney transplantation.

Circulating lymphocyte subsets in different clinical situations after renal transplantation.

Phenotypic characterization of T and B lymphocytes allows the discrimination of functionally different subsets. Here, we questioned whether changes in peripheral lymphocyte subset distribution reflect specific clinical and histopathological entities after renal transplantation. Sixty-five renal transplant recipients with either histologically proven (sub)clinical acute rejection or chronic allograft dysfunction, or without abnormalities were studied for their peripheral lymphocyte subset composition and compared with 15 healthy control individuals. Naive, memory and effector CD8(+) T-cell counts were measured by staining for CD27, CD28 and CD45RO/RA. In addition, we studied the CD25(+) CD4(+) T-cell population for its composition regarding regulatory Foxp3(+) CD45RO(+) CD127(-) cells and activated CD45RO(+) CD127(+) cells. Naive, non-switched and switched memory B cells were defined by staining for IgD and CD27. We found a severe decrease in circulating effector-type CD8(+) T cells in recipients with chronic allograft dysfunction at 5 years after transplantation. Percentages of circulating CD25(+) CD127(low) CD4(+) regulatory T cells after transplantation were reduced, but we could not detect any change in the percentage of CD127(+) CD45RO(+) CD4(+) activated T cells in patients at any time or condition after renal transplantation. Regardless of clinical events, all renal transplant recipients showed decreased total B-cell counts and a more differentiated circulating B-cell pool than healthy individuals. The changes in lymphocyte subset distribution probably reflect the chronic antigenic stimulation that occurs in these transplant recipients. To determine the usefulness of lymphocyte subset-typing in clinical practice, large cohort studies are necessary.

Precursor T-lymphoblastic lymphoma presenting as primary renal lymphoma with acute renal failure.

We report a case of acute renal failure (ARF) and bilateral nephromegaly in a patient with a history of Crohn's disease and treatment with azathioprine. Kidney biopsy revealed diffuse renal infiltration by precursor T-cell lymphoblastic lymphoma (T-LBL). At the time of diagnosis, no extrarenal manifestations of the lymphoma were detectable and therefore the lymphoma was categorized as primary renal lymphoma (PRL). Thus far, precursor T-LBL presenting as PRL has not been described before. We emphasize that in patients with ARF and bilateral renal enlargement, renal lymphoma is an important differential diagnostic consideration.

Influence of different haemodialysis modalities on AGE peptide levels: intradialytic versus long-term results.

BACKGROUND: Peptide-linked degradation products of advanced glycation end products (AGE peptides) accumulate in chronic haemodialysis (HD) patients and may contribute to a number of HD-related long-term complications, such as accelerated atherosclerosis. METHODS: The influence of a single HD session versus long-term HD on serum AGE peptides was determined. The patients were randomized to HD with a low-flux polysulfone (PS; F 6HPS), a high-flux PS (F 60S), a superflux PS (F 500S), or a superflux cellulose triacetate (CTA; Tricea 150G) dialyzer. RESULTS: During a single HD session, both AGE peptides and reference peptides decreased significantly (AGE peptides: Tricea 150G -37.0 +/- 2.9%; F 6HPS -35.5 +/- 2.4%; F 60S -39.5 +/- 4.7%, and F 500S -43.3 +/- 2.1%, p = 0.005; reference peptides: Tricea 150G -73.2 +/- 8.8%; F 6HPS -73.2 +/- 7.9%; F 60S -72.5 +/- 8.2%, and F 500S -74.1 +/- 7.3%, p = 0.005). After 12 weeks of HD with the superflux CTA, the AGE peptide levels decreased significantly (week 1: 2.7 +/- 1.1 arbitrary units, week 12: 2.5 +/- 1.2 arbitrary units, decrease 7.4%; p = 0.01), whereas the AGE peptide levels remained unchanged after HD with each of the other three modalities. The reference peptide levels did not change after 12 weeks of HD. CONCLUSION: Although AGE peptides can be effectively removed during a single HD session, superflux CTA seems to be the only modality capable of reducing AGE peptides in the long term.

Enhanced long-term reduction of plasma leptin concentrations by super-flux polysulfone dialysers.

BACKGROUND: Hyperleptinaemia in chronic haemodialysis (CHD) patients has been associated with malnutrition, which is an independent predictor of morbidity and mortality in this patient group. METHODS: To assess the influence of HD on plasma leptin, 10 CHD patients were crossover randomized to low-flux polysulfone (PS: F 6HPS), high-flux PS (F 60S), super-flux PS (F 500S) or super-flux cellulose-tri-acetate (CTA: Tricea 150G) for 12 weeks each. Blood samples were collected at the start of the study and each 12-week period. In addition, the relationship between patient characteristics, inflammation and leptin was analysed. RESULTS: At baseline, all groups showed similar leptin concentrations (mean 33.6+/-21.7 ng/ml). After a single HD session, a significant (P<0.01) decrease was observed with all three high permeable devices (Tricea 150G -52.7+/-6.4%; F 60S -63.1+/-5.7%; F 500S -68.7+/-8.2%), whereas leptin remained stable with low-flux PS. After 12 weeks, a marked increase was observed with low-flux PS (week 1, 30.4+/-23.0; week 12, 40.5+/-5.4 ng/ml, P = 0.05), no change with super-flux CTA and high-flux PS (Tricea 150G week 1, 29.4+/-23.7; week 12, 32.0+/-27.9 ng/ml, P = ns; F 60S week 1, 36.0+/-31.8; week 12, 33.0+/-31.2 ng/ml, P = ns), and a significant decrease with super-flux PS (week 1, 38.3+/-33.0; week 12, 29.5+/-31.9 ng/ml, P = 0.02). The change in leptin after 12 weeks was significantly different between super-flux PS, and both low-flux PS (P = 0.009) and super-flux CTA (P = 0.01). Besides interleukin-6 (IL-6) at the start of the study (P = 0.006), no correlations were observed between patient characteristics, parameters of inflammation and plasma leptin levels. CONCLUSIONS: Apart from low-flux PS, plasma leptin decreased considerably with all three high permeable dialysers after a single HD session. In the long run, leptin levels were lower with high-flux PS than with low-flux PS. Moreover, after switching from high-flux PS to super-flux PS (but not super-flux CTA), an additional decrease in leptin was observed. Apart from IL-6 at the start of the study, neither patient characteristics nor inflammatory parameters correlated with plasma leptin levels in this patient group.

Lipopolysaccharide concentrations during superflux dialysis using unfiltered bicarbonate dialysate.

In the present report, the design of a new dialysate delivery system to produce low to moderately contaminated dialysate is described. In addition, the first data on bacterial counts and lipopolysaccharide (LPS) concentrations in both the dialysate and the blood during hemodialysis (HD) with superflux dialyzers are presented. In this prospective study, 37 patients were randomized into two consecutive periods of 12 weeks to HD with a high flux polysulfon (PS), a superflux PS, a superflux cellulosic tri-acetate (CTA) or a superflux CTA dialyzer with filtered dialysate (CTAf), resulting in 74 periods in which measurements were obtained. Filtered dialysate showed significantly lower bacterial counts, if compared with nonfiltered dialysate (p < 0.001). As for LPS, marked differences were not observed between filtered and nonfiltered dialysate, whereas mean plasma LPS concentrations were below the value of the dialysate at all time points (p < 0.001). Plasma LPS concentrations decreased significantly during HD with all four modalities (F 60: t0 0.032+/-0.005, t180 0.026+/-0.009 endotoxin units (EU)/ml, p = 0.001; F 500S, t0 0.031+/-0.004, t180 0.027+/-0.005 EU/ml, p = 0.001; Tricea 150G: t0 0.032+/-0.004, t180 0.025+/-0.005 EU/ml, p < 0.001; and Tricea 150Gf: t0 0.034+/-0.007, t180 0.025+/-0.006 EU/ml, p < 0.001). During HD with highly permeable dialyzers and moderately contaminated dialysate, plasma LPS concentrations decreased significantly, irrespective of the material used (PS or CTA), the flux characteristics of the devices (high flux or superflux), or the presence of a bacterial filter.

Intercurrent clinical events are predictive of plasma C-reactive protein levels in hemodialysis patients.

BACKGROUND: In chronic hemodialysis (HD) patients, the repetitive induction of the acute phase response (APR) may induce a chronic micro-inflammatory state, leading to various long-term complications. METHODS: The present prospective study was designed to assess the alterations in the APR in 74 patients who were randomized to HD with a high-flux polysulfone (PS; F 60S), a super-flux PS (F 500S), or a super-flux cellulosic tri-acetate (CTA and CTA with filtered dialysate, CTA(f)) dialyzer. Blood samples collected at the start of the study and after twelve weeks were analyzed for interleukin-6 (IL-6) and C-reactive protein (CRP). In addition to the microbiological quality of the dialysate, the appearance of a "clinical event" was assessed. RESULTS: At baseline, mean IL-6 levels were within the reference range whereas mean CRP levels were slightly elevated. Mean values did not change after 12 weeks of HD with either modality. After subdividing the patients in quartiles with increasing change in plasma CRP, 23.0% of the patients showed a change of more than 8.0 mg/L. In a multiple regression analysis, CRP levels appeared to be independent of the degree of dialysate contamination, the material and the flux characteristics of the devices. In fact, the variable "clinical events" was the only significant predictor of the plasma CRP levels (P < 0.001). CONCLUSIONS: Based on these results, both PS and CTA super-flux dialyzers appear safe for clinical use. Whether changes in CRP values, which are associated with intercurrent clinical events, influence the long-term prognosis of chronic HD patients remains to be established.