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Aim To monitor B cell subsets in peripheral circulation to find a distinctive phenotypic signature of rejection in our cohort. Methods The study population consisted of 211 consecutive first renal allograft recipients who were followed up for 12 months post-transplant. One ml of EDTA peripheral venous blood was collected pre- transplant, 1 month, 3 months, 6 months, 12 months post-transplant and at the time of graft rejection. A multicolour flowcytometry was performed to monitor the percentage of peripheral Plasma cells (CD20-CD38+CD138+), Total B-cells (CD20+), Naïve B-cells (CD20+CD27-CD38-), Activated B-cells (CD20+CD38+CD138-) and Memory B-cells (CD20+CD138-CD27+). Results Of 211 cases of first kidney allograft recipients, 35 (16.58%) recipients had 38 episodes of acute allograft rejection. Percentage of activated B cells and Memory B-cells were found to be significantly higher in uremic patients ( n = 78) than those of healthy persons ( n = 40) (20.81 ± 0.7616 % vs. 14.37 ± 0.5972%, p < 0.0001 and 10.56 ± 0.5813% vs 7.658 ± 0.6626%, p = 0.0025 respectively). On the contrary, the percentage of naïve B- cells was found to be significantly lower in the patients than normal controls (61.04 ± 1.691% vs 73.62 ± 1.320%, p < 0.0001). Acute rejection episodes ( n = 38) were associated with increase in peripheral percentage of total B-cells (19.02 ± 1.457 vs. 10.80 ± 0.6338, P < 0.0001) and activated B-cells (33.92 ± 1.756 vs. 23.26 ± 1.113, P < 0.0001). On the contrary, the percentage of plasma cells and memory B-cells and naïve B- cells was significantly lower during rejection episodes (0.7447 ± 0.09 vs. 2.363 ± 0.1529, P < 0.0001, 5.871 ± 0.6677 vs. 12.12 ± 0.6584, P < 0.0001 and 44.53 ± 2.504 vs. 52.61 ± 2.488, P = 0.0311 respectively). Conclusion The percentage of activated B-cells and Memory B-cells were persistently high in uremic patients suggesting that these patients are always in a stage of immune activation. Acute rejection episodes were associated with increased percentage of activated B-cells but decrease in the percentage of plasma- and memory-B cells in the peripheral blood. Therefore, post- transplantation, periodic measurements of B-cell subsets may serve as an important marker in the prediction of acute allograft rejection. [ABSTRACT FROM AUTHOR]

Cytomegalovirus (CMV) reactivation or infection is one of the most important infectious complications in transplant recipient leading to significant morbidity and mortality. Its early detection and prompt treatment is imperative to improve transplant outcome. The present study estimated the frequency of CMV in renal transplant recipients (RTR). Various aspects of pp65Ag assay and quantitative real-time polymerase chain reaction (qRT-PCR) were evaluated in relation to the recent guidelines for CMV detection and treatment. Retrospectively, data of clinically suspected cases of CMV (1610 out of total 2681 renal transplants) were analyzed along with a comparison of pp65Ag assay and qRT-PCR. The overall incidence of CMV syndrome was 14.25%; however, the incidence of CMV viremia in the clinically suspected group was 23.73%. The proportion of positive cases with pp65Ag assay and qRT-PCR were 13.6% (95% CI; 7.9-22.3) and 19.3% (95% CI; 12.4-28.8) with a substantial agreement (Cohen's kappa = 0.632) between the 2 techniques. CMV positive recipients were treated with ganciclovir until their viral count was negative or up to 3 weeks, followed by 3 months of prophylaxis with valganciclovir. No graft failure or mortality was reported secondary to CMV infection until 3 to 5 years of follow-up. CMV infection is quite prevalent in RTR, and early detection and immediate treatment or prophylaxis is of utmost importance. qRT-PCR is the gold standard and preferred over other methods; however pp65Ag assay still holds its importance in low-economic countries and populations where CMV infection is more prevalent and financial constraints are a major limitation. [ABSTRACT FROM AUTHOR]

Comments on Claudio Ponticelli and Margarita Villa's article about the evaluation of risk factors for late kidney allograft failure. Association between body mass index and risk of graft failure; Effect of nephron dosing on late allograft failure.