Longitudinal study of human polyomaviruses viruria in kidney transplant recipients.

INTRODUCTION: Immunosuppression after kidney transplantation (KTx) exposes recipients to Human Polyomaviruses (HPyVs) infections, whose natural history is still misunderstood. METHODS: Allograft biopsies, and urine from 58 donor-recipient pairs were collected before KTx (T0) and 1 (T1), 15 (T2), 30 (T3), 60 (T4), 90 (T5), 180 (T6), 270 (T7), 360 (T8), and 540 (T9) days after transplant. Specimens were tested for JC (JCPyV) and BK (BKPyV), by quantitative Real-Time PCR. The course of post-KTx HPyVs viruria, and the association between JCPyV viruria in recipients and donors, were evaluated. RESULTS: HPyVs were detected in 3/58 (5.2%) allograft biopsies. HPyVs viruria was present in 29/58 (50%) donors and 41/58 (70.7%) recipients. JCPyV DNA was detected in 26/58 (44.8%) donors and 25/58 recipients (43.1%), 19 of whom received kidney from JCPyV positive donor, whereas BKPyV genome was detected in 3 (5.2%) donors and 22 (37.9%) recipients. The median time of JCPyV, and BKPyV first episode of replication was 1, and 171 days post KTx, respectively. At T0, JCPyV viruria of donors was associated with increased risk of JCPyV replication post-KTx; recipients with JCPyV positive donors showed lower risk of BKPyV replication post-KTx. CONCLUSIONS: The results suggested that JCPyV may be transmitted by allograft, and that its replication post KTx might prevent BKPyV reactivation. Future investigation regarding correlation between chronic exposure to immunosuppressive agents and HPyVs urinary replication are warranted.

Viral Genomic Characterization and Replication Pattern of Human Polyomaviruses in Kidney Transplant Recipients.

Human Polyomavirus (HPyV) infections are common, ranging from 60% to 100%. In kidney transplant (KTx) recipients, HPyVs have been associated with allograft nephropathy, progressive multifocal leukoencephalopathy, and skin cancer. Whether such complications are caused by viral reactivation or primary infection transmitted by the donor remains debated. This study aimed to investigate the replication pattern and genomic characterization of BK Polyomavirus (BKPyV), JC Polyomavirus (JCPyV), and Merkel Cell Polyomavirus (MCPyV) infections in KTx. Urine samples from 57 KTx donor/recipient pairs were collected immediately before organ retrieval/transplant and periodically up to post-operative day 540. Specimens were tested for the presence of BKPyV, JCPyV, and MCPyV genome by virus-specific Real-Time PCR and molecularly characterized. HPyVs genome was detected in 49.1% of donors and 77.2% of recipients. Sequences analysis revealed the archetypal strain for JCPyV, TU and Dunlop strains for BKPyV, and IIa-2 strain for MCPyV. VP1 genotyping showed a high frequency for JCPyV genotype 1 and BKPyV genotype I. Our experience demonstrates that after KTx, HPyVs genome remains stable over time with no emergence of quasi-species. HPyVs strains isolated in donor/recipient pairs are mostly identical, suggesting that viruses detected in the recipient may be transmitted by the allograft.

Living-Donor Kidney Transplant in a Patient With Type B Mayer-Rokitansky-Küster-Hauser Syndrome, Reconstructed Vagina, and Abnormal Pelvic Vessels: A Case Report.

Mayer-Rokitansky-Küster-Hauser syndrome is a rare disorder consisting of vaginal aplasia and other müllerian duct abnormalities. Urinary tract malfor-mations possibly leading to renal failure are also common. For these patients, kidney transplant remains the best option. However, aberrant anatomy and scarring from previous operations may actually preclude successful implantation of the graft. In this setting, careful pretransplant evaluation with high-resolution imaging studies and multidisciplinary planning are mandatory. We report on a patient with type B Mayer-Rokitansky-Küster-Hauser syndrome, left renal agenesis, right pelvic kidney, grade 3 cystocele, reconstructed vagina, and abnormal vasculature of the pelvis who developed end-stage renal disease due to chronic pyelonephritis. After a thorough preoperative assessment, she eventually underwent simultaneous right pelvic nephrectomy and living-donor kidney transplant. Despite the complexity of the procedure, there were no intraoperative or postoperative complications. After 1 year of follow-up, she is doing well with excellent graft function.

Posterior reversible encephalopathy syndrome after kidney transplantation in pediatric recipients: Two cases.

PRES is a neuro-clinical and radiological syndrome that can result as a consequence of several different conditions including hypertension, fluid overload, and immunosuppressive treatment. Herein, we report two children who received kidney and combined liver-kidney transplantation as treatment for renal hypodysplasia associated with bilateral vesico-ureteral reflux and methylmalonic acidemia, respectively. Early after surgery (seven and 10 days), both patients presented with hypertension and seizures. The patients' immunosuppressive regimen included steroid and calcineurin inhibitors (tacrolimus and cyclosporine, respectively) and basiliximab and one with anti-IL2 receptor. In both cases, the imaging strongly supported the diagnosis of PRES. In details, the CT scan showed hypodensities in the posterior areas of the brain, and brain MRI demonstrated parieto-occipital alterations indicative of vasogenic edema. Treatment with calcineurin inhibitors was temporally discontinued and restarted at lower dosage; arterial hypertension was treated with Ca-channel blockers. Both children fully recovered without any neurological sequels. In conclusion, in children undergoing solid organ transplantation, who develop neurological symptoms PRES, should be carefully considered in the differential diagnosis and once the diagnosis is ruled in, we recommend strict arterial blood pressure control and adjustment or withholding of calcineurin inhibitor therapy should be considered based upon blood levels.

Delayed presentation of splenic injury following diagnostic colonoscopy.

Splenic injury (SI) is a rare complication after colonoscopy, but should be considered in the differential diagnosis of acute abdominal pain following this procedure. We report a case of delayed rupture and review pertinent literature. A 70-year-old patient on oral warfarin intake underwent colonoscopy that diagnosed obstructive rectal cancer and elongated colon conditioning the endoscope's passage. After 48 h, patient experienced sharp abdominal pain with mild peritoneal signs. Contrast-enhanced CT scan evidenced large amount of abdominal-free blood collection from grade II SI. Hypovolemic shock occurred following brief clinical observation. Urgent laparotomic splenectomy and contextual Hartmann's procedure were then carried out. Postoperative course was uneventful and definitive histology confirmed splenic subcapsular haematoma and locally advanced adenocarcinoma. Perforation and bleeding more likely occurred after colonoscopy, while few cases of SI are reported in literature since 1974. Traction on the splenocolic ligament and direct trauma has been advocated as possible causes. Peritoneal adhesions and splenic diseases usually are predisposing factors although not confirmed in our patient. Anticoagulant therapy favoured delayed filling up of subcapsular haematoma while bowel obstruction added further surgical challenge. Rapid onset of hemorrhagic shock required urgent splenectomy that remains the procedure of choice among the literature reviewed.