A proliferation-inducing ligand increase precedes IgA nephropathy recurrence in kidney transplant recipients.

BACKGROUND: IgA nephropathy (IgAN) may recur in kidney transplant recipients. B-cell-activating factor (BAFF), a proliferation-inducing ligand (APRIL), and α-defensins are involved in the pathogenesis of native IgAN; however, their role on IgAN recurrence has not been previously analyzed. METHODS: Thirty-five patients with IgAN who received a kidney transplant in our center between January 1, 1993, and December 31, 2015, were included. Recurrence was diagnosed and ruled out in 14 and 11 patients, respectively, by indication biopsies. Pre-transplant, 6-month, 1-, 3-, and 5-year sera selected to measure BAFF, APRIL, and defensin by ELISA. RESULTS: Six months post-transplantation, APRIL levels (300.1 vs 1203.8 pg/mL, P = 0.033) and the mean APRIL values from 6 months to 3 years (409.8 vs 1258.0 pg/mL, P = 0.003) were higher in recurrent patients. Both 6-month APRIL levels (AUC-ROC 0.753, P = 0.033) and mean APRIL values (AUC-ROC 0.844, P = 0.004) discriminated patients with recurrence risk. By logistic regression, APRIL at 6 months (P = 0.044) and mean APRIL (P = 0.021) related to the risk of IgAN recurrence independently. Neither BAFF nor defensin related to recurrence. CONCLUSIONS: Serum APRIL increased at 6 months and mean APRIL remained higher the first 3 years in patients in whom IgAN was going to recur.

Late Plasma Cell Depletion After Thymoglobulin Induction in Kidney Transplant Recipients.

OBJECTIVES: Induction therapy with rabbit antithymocyte globulin is frequently used in kidney transplant recipients and contributes to regulating the humoral alloantibody response. However, the effect of rabbit antithymocyte globulin on B-cell subpopulations, including plasma cells, has not been previously studied in humans in vivo. MATERIALS AND METHODS: We prospectively studied a cohort of 39 adult kidney transplant recipients. Twenty patients received rabbit antithymocyte globulin as induction therapy. Peripheral blood samples were obtained pretransplant and at 6 and 12 months posttransplant. T and B cells were acquired by flow cytometry. RESULTS: Total lymphocytes and CD3 and CD4 cells significantly decreased at 6 and 12 months only in patients who received rabbit antithymocyte globulin. In contrast, the CD19 population did not change after rabbit antithymocyte globulin induction. One-year circulating plasma cells remained significantly lower than pretransplant levels in patients who received rabbit antithymocyte globulin. We observed sig-nificant differences in plasma cell numbers at 12 months after transplant between patients who received rabbit antithymocyte globulin and those patients who did not receive it (median of 5 and interquartile range of 3-17 vs median of 25 and interquartile range of 12-35; P = .001). CONCLUSIONS: Rabbit antithymocyte globulin induction leads to a late reduction in the number of circulating plasma cells at 1 year after kidney transplant. This effect can contribute to down-regulation of the humoral alloantibody response.

Evaluation of the dialyser inner diameter in online haemodiafiltration. / Valoración del diámetro interno del dializador en hemodiafiltración on-line.

INTRODUCTION: Online haemodiafiltration (OL-HDF) has been associated with increased survival. To date, the influence of the inner diameter of the hollow fibres of the dialyser on convective volume has not been well established. The objective of the study was to evaluate the effect of increasing the inner diameter of the dialyser on the convective volume and removal capacity. MATERIAL AND METHODS: We included 16 patients in posdilutional OL-HDF with autosubstitution. Each patient was analysed in 4 sessions in which the inner diameter varied; 185µm (FX60 Cordiax and FX80 Cordiax) versus 210µm (FX600 Cordiax and FX800 Cordiax). Different solutes were measured at the beginning and end of each dialysis session. RESULTS: No differences in the convective volume were found with an increased inner diameter: 32.3±3.1 vs. 31.8±3.6 l/session (FX60 vs. FX600) and 33.7±4.3 vs. 33.5±3.8 l/session (FX80 vs. FX800). The reduction percentages also did not differ: urea 83.7±4.5 vs. 84.1±3.4 for FX60 and FX600, and 82.7±4.1 vs. 83.6±3.8 for FX80 vs. FX800; creatinine similar 78.2±5.6 vs. 77.8±4.6 y 77.1±5.4 vs. 78.1±4.9; ß2-microglobulin 82.2±4.3 vs. 82.9±4.2, and 82.9±4.7 vs. 84.0±3.8; myoglobin 71.0±10 vs. 70.2±9 and 72.8±11 vs. 75.0±10; prolactin 70.4±9 vs. 68.1±9, and 72.2±10 vs. 73.4±8.2; and α1-microglobulin 22.9±10 vs. 21.6±10, and 26.5±12 vs. 28.8±11, respectively. CONCLUSION: The increase in the inner diameter of the hollow fibres did not result in improved convective volume and removal capacity.

A high sodium intake reduces antiproteinuric response to renin-angiotensin-aldosterone system blockade in kidney transplant recipients. / La ingesta elevada de sodio disminuye la respuesta antiproteinúrica del bloqueo del eje renina-angiotensina-aldosterona en el trasplante renal.

BACKGROUND: Post-transplant proteinuria is associated with lower graft and patient survival. Renin-angiotensin-aldosterone system blockers are used to reduce proteinuria and improve renal outcome. Although it is known that a high salt intake blunts the antiproteinuric effect of ACEI and ARB drugs in non-transplant patients, this effect has not been studied in kidney transplant recipients. OBJECTIVE: To analyse the relationship between sodium intake and the antiproteinuric effect of ACEI/ARB drugs in kidney transplant recipients. METHODS: We selected 103 kidney transplant recipients receiving ACEI/ARB drugs for more than 6 months due to proteinuria>1 g/day. Proteinuria was analysed at baseline and at 6 months after starting ACEI/ARB treatment. Salt intake was estimated by urinary sodium to creatinine ratio (uNa/Cr). RESULTS: Proteinuria fell to less than 1g/day in 46 patients (44.7%). High uNa/Cr was associated with a smaller proteinuria decrease (r=-0.251, P=.011). The percentage proteinuria reduction was significantly lower in patients in the highest uNa/Cr tertile [63.9% (IQR 47.1%), 60.1% (IQR 55.4%), 38.9% (IQR 85.5%), P=.047]. High uNa/Cr independently relates (OR 2.406 per 100 mEq/g, 95% CI: 1.008-5.745, P=.048) to an antiproteinuric response <50% after renin-angiotensin-aldosterone system blockade. CONCLUSIONS: A high salt intake results in a smaller proteinuria decrease in kidney transplant recipients with proteinuria treated with ACEI/ARB drugs.

Effect of calcium acetate/magnesium carbonate in the treatment of hyperphosphataemia in dialysis patients in real clinical practice. One year follow up.

BACKGROUND: This observational study was conducted to investigate the use and effectiveness of calcium acetate/magnesium carbonate (CaMg) in the treatment of hyperphosphataemia in dialysis patients in real-world clinical practice. METHODS: 120 adult CKD patients on dialysis who received CaMg alone or in combination with other phosphate binders were followed-up for 3-12 months. Serum phosphorus, calcium, magnesium, parathyroid hormone and albumin concentration was measured at baseline and after 3, 6 and 12 months respectively. In addition, CaMg dosage, use of concurrent phosphate binders, vitamin D and cinacalcet was documented. Patients were evaluated in 2 subgroups – CaMg alone (n=79) vs. CaMg + concurrent phosphate binder (n=41). RESULTS: In both subgroups serum phosphorus levels decreased significantly from baseline at 3, 6 and 12 months of CaMg treatment. The percentage achievement of recommended serum phosphorus targets improved after CaMg initiation. At month 6, a total of 78% were within the Kidney Disease Outcomes Quality Initiative (K/DOQI) target range. Total corrected serum calcium increased during CaMg treatment, but mildly exceeded the upper limit of normal in three patients only. Asymptomatic significant increases in magnesium (p<0.001) were observed in the monotherapy group at 3, 6 and 12 months. A total of 80 patients (67%) experienced episodes of mild hypermagnesaemia (>2.6mg/mL, 1.05mmol/L). CONCLUSIONS: This analysis of current clinical practice shows that – consistent with findings from a randomised controlled trial – CaMg treatment leads to marked improvement in serum phosphorus levels, helping patients in trying to achieve K/DOQI and KDIGO (Kidney Disease Improving Global Outcome) targets.