No abstract

This cohort study examined 25-year variations in cancer incidence among 11,418 Italian recipients of kidney transplantation (KT) from 17 Italian centers. Cancer incidence was examined over three periods (1997‒2004; 2005‒2012; and 2013‒2021) by internal (Incidence rate ratio-IRR) and external (standardized incidence ratios-SIR) comparisons. Poisson regression was used to assess trends. Overall, 1646 post-transplant cancers were diagnosed, with incidence rates/1000 person-years ranging from 15.5 in 1997–2004 to 21.0 in 2013–2021. Adjusted IRRs showed a significant reduction in incidence rates across periods for all cancers combined after exclusion of nonmelanoma skin cancers (IRR = 0.90, 95% confidence interval-CI: 0.76–1.07 in 2005‒2012; IRR = 0.72, 95% CI: 0.60–0.87 in 2013‒2021 vs. 1997‒2004; Ptrend < 0.01). In site-specific analyses, however, significant changes in incidence rates were observed only for Kaposi’s sarcoma (KS; IRR = 0.37, 95% CI: 0.24–0.57 in 2005‒2012; IRR = 0.09, 95% CI: 0.04–0.18 in 2013–2021; Ptrend < 0.01). As compared to the general population, the overall post-transplant cancer risk in KT recipients was elevated, with a decreasing magnitude over time (SIR = 2.54, 95% CI: 2.26–2.85 in 1997‒2004; SIR = 1.99, 95% CI: 1.83–2.16 in 2013‒2021; Ptrend < 0.01). A decline in SIRs was observed specifically for non-Hodgkin lymphoma and KS, though only the KS trend retained statistical significance after adjustment. In conclusion, apart from KS, no changes in the incidence of other cancers over time were observed among Italian KT recipients.

BK polyomavirus (BKV) is an emerging pathogen in immunocompromised patients. BKV infection occurs in 1-9 % of renal transplants and causes chronic nephropathy or graft loss. Diagnosis of BKV-associated nephropathy (BKVAN) is based on detection of viruria then viremia and at least a tubule-interstitial nephritis at renal biopsy. This paper describes the ultrasound and color Doppler (US-CD) features of BKVAN. Seventeen patients affected by BKVAN were studied using a linear bandwidth 7-12 MHz probe. Ultrasound showed a widespread streak-like pattern with alternating normal echoic and hypoechoic streaks with irregular edges from the papilla to the cortex. Renal biopsy performed in hypoechoic areas highlighted the typical viral inclusions in tubular epithelial cells. Our experience suggests a possible role for US-CD in the non-invasive diagnosis of BKVAN when combined with blood and urine screening tests. US-CD must be performed with a high-frequency linear probe to highlight the streak-like pattern of the renal parenchyma.

This study assessed the impact of cancer on the risk of death with a functioning graft of kidney transplant (KT) recipients, as compared to corresponding recipients without cancer. A matched cohort study was conducted using data from a cohort of 13 245 individuals who had undergone KT in 17 Italian centers (1997–2017). Cases were defined as subjects diagnosed with any cancer after KT. For each case, two controls matched by gender, age, and year at KT were randomly selected from cohort members who were cancer‐free at the time of diagnosis of the index case. Overall, 292 (20.5%) deaths with a functioning graft were recorded among 1425 cases and 238 (8.4%) among 2850 controls. KT recipients with cancer had a greater risk of death with a functioning graft (hazard ratio, HR = 3.31) than their respective controls. This pattern was consistent over a broad range of cancer types, including non‐Hodgkin lymphoma (HR = 33.09), lung (HR = 20.51), breast (HR = 8.80), colon‐rectum (HR = 3.51), and kidney (HR = 2.38). The survival gap was observed throughout the entire follow‐up period, though the effect was more marked within 1 year from cancer diagnosis. These results call for close posttransplant surveillance to detect cancers at earlier stages when treatments are more effective in improving survival.

We thank Yapici et al. (1) for their interest in our study (2). We agree with them that the choice of the antibody is of paramount importance in a study based on immunohistochemistry results. Our choice of the Santa Cruz antibody for the present study was based on the existing literature (3-5) and on our previous work (6). In a recent study performed on graft biopsies of transplant recipients with delayed graft function, we used the same antibody and we did not observe either any epithelial expression or colocalization with CD4 within the interstitial infiltrate (6). Indeed, in this particular set of patients, IL-17 production was mainly localized in infiltrating monocytes and neutrophils (6).In our study on antibody-mediated acute rejection, we obtained the same results on tissue samples using two independent technical approaches, immunohistochemistry and immunofluorescence coupled with confocal microscopy (2). Moreover, IL-17 expression was virtually absent in the control groups, further suggesting the specificity of the immunohistochemical staining (2). Finally, the findings of the immunofluorescence performed on cultured tubular cells were significantly correlated with the results of the ELISA performed on the supernatant of the same cells.It is well known that IL-17 is a family composed of six members (7). The conflicting results observed in some of the studies mentioned by Yapici et al. might be related to the polyclonal nature of the antibody that does not specifically recognize a single member of the IL-17 family. This observation is true also for the other antibodies from different suppliers and makes extremely hard to compare them.