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A 37-yr-old man who had undergone renal transplantation for end-stage renal failure presented with a large right pelvic mass obstructing the transplanted kidney. Initially, this was diagnosed as an anaplastic tumor while he had been on immunosuppressive treatment for kidney allograft rejection after transplantation. Despite difficulties of classic histopathology to reveal the origin of his tumor, FISH analysis revealed the presence of chromosome 12p abnormalities, strongly indicative of a germ-cell tumor-more likely seminoma-with extragonadal presentation. Because of renal dysfunction, he was treated with carboplatin (dose adjusted according to renal clearance) and etoposide, and when he experienced a rather atypical progression with bone metastases, he was treated with single-agent paclitaxel, and died almost 13 mo after initial presentation. The case adds further to the existing small list of seminoma/GCTs developing in transplant recipients, points to the unusual presentation patterns and diagnostic histopathology challenges, and presents the difficulty in therapeutic options, as a result of frequent renal dysfunction and intercurrent immunosuppressive therapy. All of these issues together with an extensive literature review are discussed in detail.

BACKGROUND AND AIMS Haemodialysis (HD) patients have a great risk of severe infection from coronovirus 2(SARS-CoV-2). However, chronic kidney disease is often associated with immunodeficiency and other existing vaccines have reduced efficacy in HD patients [1]. Humoral immune response to SARS-CoV-2 vaccination in chronic HD patients was investigated during a period of 7 months. METHOD A total of 39 patients, M/F = 34/5, aged 71 (47–90) years, dialyzed for 55(18–286) months, vaccinated with mRNA Comirnaty vaccine (BNT 162b2; BioNTech & Pfizer) were studied. Patients received two initial vaccine doses in March and April 2021, respectively, and 24 out of 39 patients received a third dose in October 2021. We analyzed the antibody response to the spike (S) antigen of SARS-CoV-2 at 0, 1, 4 and 7 months (November) after second vaccine dose in all patients. We also compared serum antibody titers at time-point 7 between the 24/39 patients and 20 healthy age-matched individuals, also vaccinated with three doses at the same months. RESULTS At time-point 0, titers of S protein-targeting antibodies(S-Abs) were 5 ± 1 AU/mL. At 1 month S-Abs were < 50 AU/mL in 2 patients (5.15%), between 51 and 100 AU/mL in 2/39 patients (5.15%), between 101 and 1000(528 ± 292) AU/mL in 19/39 patients (48.7%) and between 1001 and 10 000 (4486 ± 2547) AU/mL in 13/39 patients(33.3%). S-Abs were higher than 10 000(14 516 ± 3062) AU/mL in 3/39 patients (7.7%) after previous infection. In the 36/39 patients not infected, at 4 months there was a significant titer decrease compared with values at 1 month: from 3108 ± 4361 to 1442 ± 4357 AU/mL; P < 0.001. At 7 months, the 24/39 patients vaccinated with the third dose showed increased titers in comparison with values at 1 and 4 months, respectively (9285 ± 11 202 versus 1957 ± 2763 AU/mL; P < 0.001 and versus 584 ± 669 AU/mL; P < 0.001, respectively). Among 15/39 patients who did not receive the third dose, 4/15 with an average titer of 739 AU/mL died from other causes, 3/15 with an average titer of 25 468 AU/mL were hospitalized for COVID-19 and discharged and 8/15 showed further titer decrease (2117 ± 4887 to 950 ± 1855 AU/mL; P = 0.031). After the third dose higher S-Abs were observed in healthy controls compared with HD patients (18 050 ± 15 374 versus 9285 ± 11 202 AU/mL; P = 0.032). CONCLUSION Healthy controls showed a better humoral immune response compared with patients. Two doses of mRNA BNT162b2 vaccine induced an initial satisfactory humoral response in HD patients but S-Abs significantly declined subsequently [2]. Humoral response was significantly better after the third dose and booster immunization seems necessary [3].

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Background and Aims Hemodialysis (HD) adequacy, as measured by single pool (sp) Kt/V and urea reduction rate (URR), has been reported to be ameliorated after increasing dialysate flow rate (DFR). However, this is a matter of controversy as no benefit has been observed with dialyzers incorporating features to enhance dialysate flow distribution. We investigated the effect of increasing DFR on dialysis adequacy and on various laboratory parameters. Method Twenty-three patients, M/F=20/3, aged 65(44-89) years, dialyzed thrice weekly for 50(6-274) months, using polysulfone low flux dialyzers, participated in an annual randomized cross-over study. Patients were dialyzed with DFR of 500 ml/min and 700 ml/min for 6 consecutive months respectively, according to their usual dialysis prescription and with ultrafiltration volumes according to clinical need. Blood was sampled before and at the end of midweek sessions at the beginning of the first, 7th and 13rd month for urea, creatinine, potassium, sodium, albumin, total Ca and phosphate (sP). URR, spKt/V, corrected for albumin Ca(sCa) and sCa x sP product (CaxP) values were calculated. Results Under both 500 and 700 ml/min DFRs used, the expected post-dialysis alterations were found: decreased values in serum urea (respectively 161,5±38,0 to 49,9±20.1-p<0,001 and 140,3±30 to 56,0±20.4 mg/dl-p<0,001), creatinine (respectively 10,2±2 to 3.9±1,2-p<0,001 and 10,2±3,3 to 4,1±1,6 mg/dl-p<0,001), potassium (respectively 5,2±0,7 to 3,7±0,3 mM-p<0,001 and 5,3±0,6 to 3,9±0,3mM-p<0,001) and phosphate (respectively 5,4±1,7 to 2,9±0,6-p<0,001 and 5,7±1,6 to 2,6±0,6 mg/dl-p<0,001); increased values in serum albumin (respectively 4,3±0,4 to 4,7±0,4 g/dl-p=0,001 and 4,2±0,3 to 4,7±0,4 g/dl-p<0,001) and sCa (9,1±0,7 to 11,3±0,9 mg/dl-p<0,001 and 8,7±0,6 to 9,9±0,7 mg/dl-p<0,001). After increasing DFR from 500 to 700 ml/min we observed no reductions in pre-dialysis serum urea and creatinine levels or URR (68,6±8,1% to 69,9±7,9%-p=NS) and Kt/V (1,41±0,4 to 1,42±0,3-p=NS) values. However, under DFR of 700ml/min post-dialysis sCa, sP and sCa x sP product values were always lower compared with those under DFR of 500 ml/min (respectively 9,9±0.7 vs 10,8±0.8 mg/dl-p<0,001, 2,6±0,6 vs 2,9±0,6 mg/dl-p=0,02 and 25,6±6,2 vs 30,9±6,7 mg2/dl2-p<0,001). Conclusion DFR increase from 500 to 700 ml/min did not lead to favorable effects on dialysis adequacy but resulted in post-dialysis amelioration of serum calcium and phosphate levels and may be useful in cases of hypercalcemia, hyperphosphatemia and calcifications. DFR increase utility needs further investigation in patients with disorders of calcium-phosphate metabolism.