SV40 Staining Research Articles

Polyomavirus Associated Nephropathy: Frequency and Graft Survival Analysis in Northeast of Iran.

Background & Objective:Polyomavirus-associated nephropathy (PVAN), mainly caused by the BK virus, is one of the most important infectious complications of kidney transplantation. The leading histopathologic characteristics of PVAN is viral cytopathic effects, such as nucleomegaly with smudged or clumped chromatin and intranuclear ground-glass inclusion, mostly in tubular epithelial cells. Moreover, tubular necrosis, tubulitis, interstitial inflammation, atrophy, and fibrosis have been noted. Positive immunohistochemistry (IHC) staining for SV-40 highlights the infected epithelial cells of renal tubules.Methods:A total of 85 core needle biopsies of transplanted kidneys were evaluated histologically and were stained for SV-40 using the IHC method. In addition, a follow-up of graft failure was performed.Results:Our findings revealed that the frequency of polyomavirus infection in kidney transplant patients in the Northeast of Iran is 4.7%. There was no significant correlation between PVAN and graft rejection. Although a higher rate of graft loss was observed in PVAN patients, in comparison with non-PVAN patients (25% vs. 14.8%), the difference was not statistically significant. Moreover, patients with immunohistochemically confirmed PVAN and those with histopathologic features of viral-like cytopathic effects had significantly lower graft survival in the follow-up period (42.5 vs. 196.8 months and 109.4 vs. 205.7 months, respectively).Conclusion:The frequency of polyomavirus infection in kidney transplant patients in the Northeast of Iran is 4.7%. There was no significant correlation between PVAN and graft rejection. Furthermore, we observed that polyomavirus infection accelerates the course of graft loss.

Human BK Polyomavirus Nephropathy (BKVN) In Non- Kidney-Transplant Patients

Abstract Introduction/Objective Human BK polyomavirus nephropathy (BKVN) occurs in up to 10% of renal transplant recipients, and can result in graft loss. Transplant biopsy is the gold standard to diagnose BKVN, and SV40 immunohistochemical (IHC) staining is helpful in confirming the diagnosis. BKVN is uncommon outside the setting of renal transplantation. To understand more about its occurrence in other contexts, we reviewed our renal biopsies files for cases of BKVN. Methods Our renal biopsy files for the past 20 years were reviewed for all cases with a diagnosis of BKVN or polyoma virus infection, and the clinical characteristics of the affected patients noted. Results Evidence of BKVN was found in 44 renal biopsies, of which 39 (86%) were renal transplant patients. Of the remaining five patients (14%), two had undergone heart transplantation, one lung transplantation, one was undergoing chemotherapy for acute lymphoblastic leukemia, and one patient had active HIV infection. All patients had elevated serum creatinine, and four out of five patients had documented BK viremia. Four of the five biopsies showed typical tubular injury with viral nuclear cytopathic changes (inclusions). In the lung transplant patient, the biopsy showed advanced chronic tubulointerstitial injury without distinct viral inclusions, but SV40 staining confirmed the presence of BK virus antigen. Conclusion The BKVN is distinctly uncommon outside the context of kidney transplantation. In our series, 14% of patients with BKVN were not kidney transplant recipients, but all were immune compromised in some fashion. The pathologic features of BKVN appear similar, regardless of whether the host is a renal transplant recipient or not. Although uncommon, it is important to consider the possibility of BKVN in non-renal transplant patients with persistent or progressive renal dysfunction.

Viremia and viruria of trichodysplasia spinulosa‐associated polyomavirus before the development of clinical disease in a kidney transplant recipient

Trichodysplasia spinulosa (TS) is a rare disease associated with immunosuppression and induced by a polyomavirus denominated Tricodisplasia Polyomavirus (TSPyV). We report a case of TS 6months after kidney transplantation in a 65years-old woman under immunosuppression therapy with prednisone, mycophenolate and tacrolimus. The patient developed follicular papules on the face with a thickening of the skin and alopecia of the eyebrows, leading to distortion of the face and a leonine appearance characteristic of the disease. The skin biopsy confirmed the clinical diagnosis and the presence of TSPyV DNA in the skin was detected. Staining for SV40 was positive. Immunosuppression was changed: mycophenolate was withdrawn, tacrolimus reduced and everolimus added. Intravenous cidofovir and later on leflunomide were added. Although the literature has reported clinical success with topical cidofovir, we were unable to use it because this drug is not available. There was an improvement of skin lesions and on cosmetic appearance. The patient had three rejections (one clinically diagnosed and two other biopsy proven), progressed with renal failure and graft loss. Retrospective analysis of stored urine and blood samples detected TSPyV DNA in some of those samples two months before the TS clinical development. This case highlights the TSPyV detection in blood and urine samples before the development of skin lesions.

BK polyomavirus and urothelial carcinoma: Experience at a tertiary care centre in India with review of literature

IntroductionBK polyomavirus is ubiquitous and remains dormant in the urothelial tract, reactivating and replicating in the immunocompromised state especially in the setting of post-renal transplantation where it is believed to be directly oncogenic based on recent reports. Its oncogenic role in the immunocompetent host is controversial. This study aimed to investigate the association of BK polyomavirus in Urothelial Carcinoma. Material and methodsPatients with suspected urothelial carcinoma (UC) admitted under Department of Urology over a period of one year were recruited and transuretheral bladder tumor (TURBT) resection was performed, along with sampling of cystoscopically normal-appearing urothelium away from the tumor. In addition, cystectomy specimens with UC were included, with sampling of grossly normal-appearing urothelium away from the tumor. Immunohistochemistry (IHC) for SV40 T-Antigen and chromogenic in situ hybridization (CISH) using BK polyomavirus specific probe was performed on the paired samples (tumor and normal). ResultsTwenty-three TURBT and 14 cystectomy specimens were assessed. None of the cases showed evidence of BK polyomavirus infection in tumor or in surrounding mucosa by IHC. CISH performed in ten cases were also found to be negative. In comparison, one post-renal transplant urothelial carcinoma in our experience showed diffuse SV40 staining. ConclusionsThis study suggests that BK polyomavirus infection is not associated with urothelial malignancy in the immunocompetent setting unlike in the immunocompromised setting where it should always be investigated for.

265 BK-Virus Positive Invasive High-Grade Urothelial Carcinoma in an 8-Year-Old Renal Transplant Recipient With BK Virus Nephropathy

Urothelial carcinoma is extremely rare in children and may be fundamentally different than in adults. Fewer than 30 cases have been reported in patients under 10 years old. BK polyomavirus infection is a major problem in transplantation, especially in renal transplant recipients. According to literature, 1%-10% of renal transplant recipients develop polyomavirus-associated nephropathy. The possibility that BK polyomavirus may be carcinogenic in humans is controversial, but SV40 large T antigen is known to inhibit tumor suppressors pRB and p53, and to transform some cell lines in culture. Adult renal transplant recipients have a 3-5x increased risk of urothelial carcinoma. The cystoprostatectomy specimen from an 8-year-old boy with a history of renal transplantation was processed according to standard procedure, and evaluated using H&E and immunohistochemical stains (IHC). Additional ancillary testing included molecular studies for BK virus using PCR for VP1 and identity testing using HLA typing. The patient was an 8-year-old ex 32-week gestation twin boy with a history of chronic kidney disease and developmental delay. He had end-stage renal disease of unclear etiology and underwent kidney transplantation five years earlier from a living non-related donor who was a smoker. He had been immunosuppressed since transplantation, and his course was complicated by uncontrolled BK viremia and BK nephropathy despite prolonged treatment. Five years after his renal transplant, he was noted to have gross painless hematuria. Biopsy of a bladder lesion showed high-grade urothelial carcinoma, and ureteroscopy of native and transplant ureters showed no gross malignancy. He underwent cystoprostatectomy and bilateral native nephroureterectomies with cutaneous ureterostomy from the transplant kidney. Histological examination of the bladder revealed invasive high-grade urothelial carcinoma with micropapillary features with invasion into muscularis propria. Lymphovascular invasion was also noted. The bilateral native kidneys were atrophic with simple cysts and chronic inflammation. The prostate, bilateral seminal vesicles, vas deferens, and distal transplant ureter cuff were negative for tumor. Immunohistochemical staining of the tumor for SV40 antigen showed strong and diffuse staining. In contrast, immunohistochemistry for viral protein VP1 was negative. Molecular testing for BK virus by PCR for VP1 was positive. Immunohistochemistry for mismatch repair proteins showed normal, preserved expression. Identity testing confirmed that the tumor cells belonged to the patient and not to the donor. BK virus positivity has been reported in rare cases of urothelial carcinomas, mainly in adult transplant patients. To our knowledge, this is the first reported incidence of BK virus-associated urothelial carcinoma in a pediatric patient. Absence of late VP1 expression by IHC in conjunction with positive SV40 staining and positive BK virus PCR is consistent with a non-productive BK virus infection. Pathologists should be aware that identity testing should be considered in transplant patients with urothelial carcinoma to confirm the genetic origin of the tumor. Micropapillary differentiation may be a feature of BK virus-associated carcinoma.

High-level JCPyV viruria after kidney transplantation—Clinical and histopathological findings

BackgroundThe significance of JC polyomavirus (JCPyV) after kidney transplantation ranges from irrelevant to full-blown nephropathy or PML. ObjectivesTo investigate the clinical significance of high-level JCPyV viruria and JCPyV primary infections after kidney transplantation. Study designJCPyV viruria was detected in routine screening by quantitative real-time PCR in 40/238 kidney transplant recipients and was high-level (>107 copies/ml) in 17 patients. A protocol biopsy at the time of JCPyV viruria was available from 10 patients. ResultsPeak urine viral loads were 1.0×107−2.5×109 copies/ml in the 17 high-level viruria patients. 6/15 (40%) patients with high-level JCPyV viruria with pretransplant sera available were JCPyV IgG negative suggesting that JCPyV viruria resulted from the donor graft in most cases. No acute graft dysfunction was associated with JCPyV viruria. No positive SV40 staining was detected in protocol biopsies, and no specific histopathology was associated with high-level viruria; JCPyV nephropathy was not found. No differences were seen in histopathology or graft function at 3 years in patients with high-level viruria compared to non-JCPyV viruric patients transplanted during the same time period, and outcome was similar in patients with presumably primary and reactivated JCPyV. The mean estimated GFR at last follow-up was 44ml/min (range 12–60ml/min). One graft with high-level viruria was lost 9 years posttransplant due to recurrent IgA nephropathy ConclusionsHigh-level JCPyV viruria seems to be associated with primary JCPyV infection reflecting the average seroprevalence of 60%, but is not stringently associated with inferior graft function or survival, or histopathological changes.

Nephropathy Evolving Within the First Two Posttransplant Months With No Typical Cytopathic Lesions: Two Cases Presentation

BackgroundWe report 2 cases of polyomavirus-associated nephropathy (PyVAN) emerging within the initial 8 posttransplant weeks. These cases were characterized by intraepithelial BK virus replication without typical nuclear inclusions in epithelial cells. Methods and ResultsA 70-year-old male recipient of a cadaveric kidney transplant had experienced unsatisfying graft function since the time of transplantation (Tx). One month after Tx, results of a graft biopsy revealed mild tubulointerstitial inflammation. No intraepithelial nuclear inclusions suggestive of viral infection were present at that time. The patient received intravenous methylprednisolone, and the dosage of tacrolimus was increased. Due to a further drop in the glomerular filtration rate, a subsequent kidney biopsy was performed during posttransplant week 10, which revealed lesions typical of PyVAN. Retrospectively performed SV40 staining revealed that intragraft polyomavirus replication was already present on posttransplant day 30. Basic immunosuppression reduction and ciprofloxacin administration were followed by BK viremia elimination, stabilization of graft function, and resolution of PyVAN. In another patient, a 62-year-old male recipient of a cadaveric renal graft, BK viremia was monitored from the time of Tx. Two months after Tx, the patient was found to have a BK viral load of 6 × 4 log10/mL. Results of the graft biopsy revealed fully preserved tubular epithelium, but SV40 staining was positive in some of these cells. After basic immunosuppression reduction and introduction of ciprofloxacin, the BK viral load dropped to 1 × log10/mL with graft function stabilization. ConclusionsPyVAN may emerge as early as 4 weeks after Tx, with near-normal or acute rejection–like graft morphology. The early monitoring of plasma BK viral load, as well as SV40 staining, avoids misdiagnosis of this severe posttransplant complication.

Clinical and Pathological Study of Polyomavirus-Associated Nephropathy after Renal Transplantation

Polyomavirus infection has emerged as an important cause of polyomavirus-associated nephropathy (PVAN) leading to allograft dysfunction and loss. The aim of this study is to investigate pathological features and clinical characteristics of PVAN. We prospectively investigated 351 renal allografts performed in Jinling Hospital. PVAN was diagnosed by light microscopic examination and a positive immunohistochemistry staining of anti-SV40 large T antibody in a biopsy specimen. 31 patients were diagnosed with PVAN (8.8%). The patients with PVAN typically presented as allograft dysfunction with an asymptomatic rise in serum creatinine about 3 to 39 months posttransplant. Urinary decoy cells were positive in 4 patients (12.9%). The histologic changes of PVAN are not pathognomonic and can be mistaken for allograft rejection, i.e. tubulointerstitial nephritis with varying degrees of inflammatory infiltrates, tubulitis, tubular atrophy and fibrosis. Typical findings on histology are focal interstitial mononuclear inflammatory cell infiltrates, presence of plasma cells, necrotic tubular epithelium, and presence of homogenous intranuclear inclusion bodies. Immunohistochemistry with SV40 staining is positive in allograft. CD3, CD4, CD8, CD68 positive cells are increased in PVAN group than the non-PVAN group, but none of HLA-DR and IL-2R expression is positive in PVAN patients. MPA AUC 0-12 and TAC trough levels are increased in PVAN group than non-PVAN group at biopsy. We have treated 31 patients with biopsy-proven PVAN with leflunomide. Increased intensity of immunosuppression appears to increase the likelihood of PVAN. The definitive diagnosis of PVAN requires renal biopsy. Immunohistochemistry with SV40 staining has been used as an indirect method to document the presence of PVAN.

Surveillance Renal Allograft Biopsy on Diagnosis of BK Virus Nephropathy in Chinese Renal Transplant Recipients

Objective: We prospectively investigated 121 renal allograft biopsy specimens performed in our center. Methods: BKVAN was diagnosed by light microscopic examination and a positive immunohistochemistry staining of anti-SV40 large T antibody in a biopsy specimen. Results: Of the 121 patients, nine were diagnosed with BKVAN (7.4%). Nine patients whith BKVN classically presents as allograft dysfunction with an asymptomatic rise in serum creatinine, about 3 to 39 months posttransplant. Urinary decoy cells are positive in two patients (22.2%). The histologic changes of BKVN are not pathognomonic, and can be mistaken for allograft rejection, ie, tubulointerstitial nephritis with varying degrees of inflammatory infiltrates, tubulitis and tubular atrophy, and fibrosis. Typical findings on histology are focal interstitial mononuclear inflammatory cell infiltrates, presence of plasma cells, necrotic tubular epithelium, and presence of homogenous intranuclear inclusion bodies. Immunohistochemistry with SV40 staining were positive in allograft. Graft loss occurred in one patient and the other 8 showed progressive allograft dysfunction. Conclusion: The definitive diagnosis of BKV disease requires renal biopsy. Immunohistochemistry with SV40 staining has been used as an indirect method to document the presence of BKVAN.

Preemptive Retransplant for BK Virus Nephropathy Without Concurrent Transplant Nephrectomy

Preemptive Retransplant for BK Virus Nephropathy Without Concurrent Transplant Nephrectomy

Association of bladder adenocarcinoma and BK virus infection in a pancreatico-renal transplant recipient.

Viral infection has been related to post-transplantation tumour development, particularly Epstein–Barr virus, human papillomavirus, hepatitis B and C viruses, and herpes virus 8. Recently, BK virus (BKV) has emerged as an important cause of tumour formation in solid organ transplant recipients. BKV oncogenic potential relates to the ability to inactivate the functions of tumour suppression proteins p53 and pRB family, and induction of chromosomal aberrations. We report a case of urinary bladder adenocarcinoma in a pancreatico-renal transplant recipient which was diagnosed 2 years after BKV infection. Immunohistochemical staining for SV-40 was positive in neoplastic cells but negative in non-neoplastic cells.

Therapeutic options in BK virus-associated interstitial nephritis

CASE PRESENTATION A female in her 30s developed renal failure secondary to mixed connective tissue disease-associated immune complex glomerulonephritis. Her past medical and family history was otherwise unremarkable. She underwent a pre-emptive renal transplantation from her mother, receiving induction with dacluzimab and had an uneventful post-transplant course. Her immunosuppressive regimen at discharge included prednisone 5 mg daily, mycophenolate mofetil 1000 mg twice daily, tacrolimus 4 mg twice daily, and prophylaxis with oral gancyclovir and trimethoprim–sulfamethoxazole, atenolol for hypertension, and famotidine, iron and calcium/vitamin D supplements. Her baseline serum creatinine after the transplant was 1.5 mg/dl. Two years after receiving the transplant, she developed fever and dysuria and was treated for a presumed urinary tract infection (negative urine cultures). Her serum creatinine during this episode increased to 1.9 mg/dl and remained elevated in this range. Her physical examination was unremarkable and her blood pressure was 130/80 mm Hg. A renal ultrasound did not show any abnormalities. A renal biopsy was performed. RENAL BIOPSY FINDINGS Sampling for light microscopy consisted of a single core of renal cortex containing eight glomeruli, all of which appeared histologically unremarkable. There was diffuse, moderate to severe interstitial inflammation involving the entire cortex sampled, and composed of lymphocytes and less prominent plasma cells. The interstitial inflammation extended across tubular basement membranes to produce extensive tubulitis with multiple tubules containing greater than 10 lymphocytes. Proximal tubules also displayed diffuse degenerative changes and interspersed, enlarged, hyperchromatic nuclei with intranuclear viral inclusions typical of BK virus. This diagnosis was subsequently confirmed by immunohistochemical staining for SV40. There was moderate tubular atrophy and interstitial fibrosis involving 50% of the cortex sampled. Blood vessels appear unremarkable (Figure 1). The renal biopsy findings were diagnostic of BK virusassociated interstitial nephritis (BKVIN). In the light of the diffuse distribution of the interstitial inflammation and tubulitis but more localized viral inclusions, the possibility of coexistent acute cellular rejection could not be excluded.

Isotretinoin prevents chronic allograft nephropathy (CAN)

We report 2 cases of polyomavirus-associated nephropathy (PyVAN) emerging within the initial 8 posttransplant weeks. These cases were characterized by intraepithelial BK virus replication without typical nuclear inclusions in epithelial cells.A 70-year-old male recipient of a cadaveric kidney transplant had experienced unsatisfying graft function since the time of transplantation (Tx). One month after Tx, results of a graft biopsy revealed mild tubulointerstitial inflammation. No intraepithelial nuclear inclusions suggestive of viral infection were present at that time. The patient received intravenous methylprednisolone, and the dosage of tacrolimus was increased. Due to a further drop in the glomerular filtration rate, a subsequent kidney biopsy was performed during posttransplant week 10, which revealed lesions typical of PyVAN. Retrospectively performed SV40 staining revealed that intragraft polyomavirus replication was already present on posttransplant day 30. Basic immunosuppression reduction and ciprofloxacin administration were followed by BK viremia elimination, stabilization of graft function, and resolution of PyVAN. In another patient, a 62-year-old male recipient of a cadaveric renal graft, BK viremia was monitored from the time of Tx. Two months after Tx, the patient was found to have a BK viral load of 6 × 4 log10/mL. Results of the graft biopsy revealed fully preserved tubular epithelium, but SV40 staining was positive in some of these cells. After basic immunosuppression reduction and introduction of ciprofloxacin, the BK viral load dropped to 1 × log10/mL with graft function stabilization.PyVAN may emerge as early as 4 weeks after Tx, with near-normal or acute rejection–like graft morphology. The early monitoring of plasma BK viral load, as well as SV40 staining, avoids misdiagnosis of this severe posttransplant complication.

Human fibroblasts transformed by the early region of SV40 DNA: Analysis of “free” viral DNA sequences

Human fibroblastic cells (HF) were transformed with the early region of the simian virus 40 genome (0.15 – 0.73 map units) by using the DNA-calcium phosphate coprecipitation technique of F. L. Graham and A. J. Van der Eb (1973, Virology 52, 456–467). Transformation resulted in altered morphology and ability to grow in agarose. The SV40-transformed human fibroblasts (SVHF-A) have a limited life span and reach “senescence” after 10–11 passages. Analysis of the low molecular weight DNA extracted from SVHF-A cells shows a relatively high amount of free viral DNA sequences in circular supercoiled form. These circular molecules are very heterogeneous in size and contain sequences corresponding to the early region of the SV40 genome. Part of them may contain cellular DNA sequences as well. In situ hybridization experiments indicate that a minority of the SVHF-A cells (2–3%) are spontaneously induced to synthesize free viral DNA molecules and their frequency is increased by mitomycin C treatment. Immunofluorescence staining for SV40 T antigens also indicates that the cells producing free viral DNA contain higher T-antigen levels than the rest of the population. Our data suggest that the “free” viral DNA molecules derive from integrated viral sequences following replication in a minority of the cells rather than originating from a persistent extrachromosomal replication in every cell.