BKV DNA Research Articles

Serological evidence of vertical transmission of JC and BK polyomaviruses in humans

Vertical transmission of JC virus and BK virus has been investigated by few authors, with conflicting results. We performed a combined serological and genomic study of 19 unselected pregnant women and their newborns. Blood and urine samples were collected during each gestational trimester from the pregnant women. Umbilical cord blood, peripheral blood, urine and nasopharyngeal secretion samples were taken from newborns at delivery and after 1 week and 1 month of life. Polyomavirus DNA was detected by nested PCR. Polyomavirus IgG-, IgM- and IgA-specific antibodies were measured in maternal and newborn serum samples using a virus-like-particle-based ELISA method. BKV and JCV DNA were detected in urine from 4 (21 %) and 5 (26 %) women, respectively. BKV and JCV seroprevalences in the pregnant women were 84 % and 42 %, respectively. Using a rise in the IgG level or the transient appearance of an IgA or IgM response as evidence of infection in the newborn, we detected BKV and JCV infections in four (21 %) and three (16 %) newborns, respectively. Three infants had serological evidence of infection with both BKV and JCV. In two of the four possible BKV-infected newborns, the mothers seroconverted during pregnancy, while another mother was viruric and IgA seropositive. The mother of one of the three possible JCV-infected newborns was viruric and IgA seropositive; another mother was viruric. These results suggest JC virus and BK virus can be transmitted from mother to newborn during pregnancy or soon after birth.

HIV-associated salivary gland disease: a role for BK birus

HIV-associated salivary gland disease (HIV-SGD) is disfiguring and causes significant morbidity in the HIV population. Evidence detailing the epidemiology of HIV-SGD suggests the involvement of a viral opportunist in its pathogenesis, yet the specific etiology of HIV-SGD remains unclear. To determine the role for an opportunistic virus as the etiologic agent of HIV-SGD, we hypothesized that HIV-SGD was a manifestation of primary infection or reactivation with a DNA tumor virus, BKV, during immune suppression. The central hypothesis of this work is that viral pathogenesis is essential to the development of salivary gland disease. Results show for the first time that polyomavirus, BKV, is associated with HIV-SGD. BKV DNA, RNA, and protein were consistently detected in salivary gland biopsies and in the peripheral blood and oral fluids from HIV-SGD patients and not in control subjects. To confirm the in vivo findings, an in vitro model was created whereby parotid and submandibular salivary gland cells were productively infected with BKV, demonstrating each part of the viral life cycle. Salivary gland tropism was confirmed and the BKV receptor on salivary gland cells was defined. BKV transmission and pathogenesis is not well understood. Importantly, these studies suggest a role for BKV in HIV-SGD and that BKV transmission may occur via the oral route. The long-term goal of this project is to make critical strides toward understanding the etiology of SGD in order to go beyond the ineffective palliative treatment that is currently the standard of care.

1- O -Hexadecyloxypropyl Cidofovir (CMX001) Effectively Inhibits Polyomavirus BK Replication in Primary Human Renal Tubular Epithelial Cells

Antiviral drugs for treating polyomavirus BK (BKV) replication in polyomavirus-associated nephropathy or hemorrhagic cystitis are of considerable clinical interest. Unlike cidofovir, the lipid conjugate 1-O-hexadecyloxypropyl cidofovir (CMX001) is orally available and has not caused detectable nephrotoxicity in rodent models or human studies to date. Primary human renal proximal tubular epithelial cells were infected with BKV-Dunlop, and CMX001 was added 2 h postinfection (hpi). The intracellular and extracellular BKV DNA load was determined by quantitative PCR. Viral gene expression was examined by quantitative reverse transcription-PCR, Western blotting, and immunofluorescence microscopy. We also examined host cell viability, proliferation, metabolic activity, and DNA replication. The titration of CMX001 identified 0.31 μM as the 90% effective concentration (EC(90)) for reducing the extracellular BKV load at 72 hpi. BKV large T antigen mRNA and protein expression was unaffected at 24 hpi, but the intracellular BKV genome was reduced by 90% at 48 hpi. Late gene expression was reduced by 70 and 90% at 48 and 72 hpi, respectively. Comparisons of CMX001 and cidofovir EC(90)s from 24 to 96 hpi demonstrated that CMX001 had a more rapid and enduring effect on BKV DNA and infectious progeny at 96 hpi than cidofovir. CMX001 at 0.31 μM had little effect on overall cell metabolism but reduced bromodeoxyuridine incorporation and host cell proliferation by 20 to 30%, while BKV infection increased cell proliferation in both rapidly dividing and near-confluent cultures. We conclude that CMX001 inhibits BKV replication with a longer-lasting effect than cidofovir at 400× lower levels, with fewer side effects on relevant host cells in vitro.

Evaluation of a BK virus real-time PCR assay designed using novel bioinformatics technology

Monitoring of active polyomavirus BK (BKV) infections by quantitative real-time PCR is becoming a progressively more routine practice in the care of renal transplant patients due to the potential for these infections to injure transplanted kidneys. Quantitative BKV results from a previously validated, laboratory-developed real-time PCR assay based on commercially available MGB Alert® reagents were compared to results obtained from the same urine and plasma specimens using a commercially designed real-time PCR assay by IntelligentMDx. When compared qualitatively, the two assays performed identically with the exception of one urine specimen in which BKV DNA was detected near the lower limit of quantification by the MGB Alert® assay. A quantitative comparison of the results showed an average 0.55 log 10 copies/mL difference between the two assays. These findings suggest that despite small differences, the IntelligentMDx assay could be adopted for clinical BKV monitoring of renal transplant patients.

Clinical diagnosis of BK virus associated nephropathy in renal transplant recipients

Objective To investigate the methods for clinical diagnosis of BK virus associated nephropathy(BKVAN)in renal transplant recipients.Methods Urine and peripheral blood(PB)were taken from90 renaltransplant recipients fo rBKV cytological testing and real-time PCR for BKV DNA at the post-transplantafion month 1,3,6,9,and 12.Graft biopsies were analysed for SV40-T by immunohistochemical method.Graft biopsies and urinary sediments of recipients with BKVAN were taken to momtor viral partieles by conventional transmission electron microscopy(EM).Results By one post-transplant year,urinary decoy cells(median,8/10 HPF),BKV viruria(mediall,2.60×10~5 copies/ml),viremia(median,9.65×10~3copies/ml).and BKVAN occurred in 42.2%,45.6%,22.2%,and 5.6%of patients,respectively.BKVAN was diagnosed in 5 calves.Conclusion Intensive and regular BKV monitoring is necessary for renal transplant recipients.The correct diagnosis of BKVAN depends on routine histopathological examination combined with immunohistochemistry or electron microscopy and the clinical manifestationa. Key words: Kidney transplantation; Virus; Detection; Diagnosis

Sequence variations of the VP1 gene of Polyomavirus hominis 1 among Bulgarians

Polyomavirus hominis 1 (BK virus, BKV) is an important pathogen in the field of transplantation medicine. BKV reactivation among renal-transplant recipients could cause BK associated nephropathy, which has unfavorable prognosis and is a cause for graft rejection. It is not clear why only few transplanted patients develop BK associated nephropathy while most exhibit asymptomatic viruria. One of the possible reasons lies in the mutations of the VP1 gene, encoding the main structural protein, bearing important determinants for the recognition of specific cellular receptors. The change of amino acid sequence could result in altered pathogenicity of BKV. The amplified sequences of BK in this research were from urines of patients with various clinical conditions along with healthy individuals. Nevertheless the sequence analysis which was undertaken did not show correlation between the viral genotype and the clinical condition. It was demonstrated that the most common BKV genotype in Bulgaria is genotype I and that the strains common in Bulgaria (genotypes I and IV) have typical European origin. Most of the sequenced BKV DNA samples (8/10) were correlated with the highest degree of similarity (81%) to the subcluster Ib. A specific place among the samples is taken by Pr-9, amplified from the urine of a pregnant woman that has a different evolutionary origins and might establish the beginning of a new distinct BKV strain.

Transitional cell carcinoma of renal allograft associated with BK virus infection

AbstractBK virus (BKV) has oncogenic properties and has been associated with different malignancies. However, reports of malignancy in renal transplant recipients are scarce and circumstantial. We report on a renal transplant recipient with a diagnosis of BKV nephropathy for several years, who subsequently developed a renal allograft mass. Renal allograft mass biopsy revealed a high‐grade transitional cell carcinoma. The patient underwent a renal allograft nephrectomy and returned to hemodialysis. Neoplastic tissue was positive for BKV DNA by polymerase chain reaction (PCR) and large T‐antigen (TAg) by immunohistochemical staining. In contrast, BKV DNA by PCR was negative in non‐neoplastic tissue. The presence of BKV DNA and TAg exclusively in the neoplastic tissue, suggest that malignancy was induced by BKV. Of note, JC virus DNA by PCR was negative in the neoplastic tissue. BKV is associated with transitional cell carcinoma of the allograft renal pelvis and that warrants monitoring these patients for this possibility.

BK Virus in Solid Organ Transplant Recipients

The human polyomavirus BK (BKV) is linked to two ma-jor complications in transplant recipients, polyomavirus-associated nephropathy (PyVAN) (1–4) and polyomavirus-associated hemorrhagic cystitis (PyVHC) (5,6). PyVAN andPyVHC have been encountered in a variety of immunod-eficient patients (7,8), but most cases of PyVAN arise inkidney transplant patients at rates of 1–10%, while PyVHCpreferentially affects allogeneic hematopoietic stem celltransplant patients at rates of 5–15% (7,9). BKV hasbeen less frequently associated with other pathologies,such as ureteric stenosis, pneumonitis, hemophagocyticsyndrome, encephalitis, retinitis, multiorgan failure andpolyomavirus-associated multifocal leukoencephalopathy(PyVML) (10–12), a complication of the central nervoussystem mostly caused by the closely related polyomavirusJC (JCV) (13). The objective of this section is to updateprevious recommendations (14) regarding diagnosis andmanagement of BKV replication and PyVAN in solid organtransplantation (SOT) using the grading proposed by Grosset al. (15).BKV belongs to the family Polyomaviridaetogether withfive other polyomaviruses detected in human specimens,that is JCV, KI virus, WU virus, Merkel cell carcinoma virusand Simian virus 40 (16,17). The virions are nonenvelopedparticles of 42 nm diameter and fairly resistant to envi-ronmental inactivation (18). The circular double-strandedDNA genome of

Comparative evaluation of two automated systems for nucleic acid extraction of BK virus: NucliSens easyMAG versus BioRobot MDx

The objective of this study was to compare the performance of two automated nucleic acid extraction systems. Specifically, the NucliSens easyMAG system (bioMerieux, Marcy l’Etoile, France), which incorporates magnetic bead technology, was compared with the BioRobot MDx system (Qiagen GmbH, Hilden, Germany), which uses a silica membrane-based method of nucleic acid extraction. Nucleic acids from the BK virus (BKV DNA) were extracted from 98 plasma and 57 urine specimens using the Real-Q BKV quantitation kit (Biosewoom, Seoul, Korea). Failed PCR was defined as negative BKV DNA results having more than 36 threshold cycles of the internal control by the manufacturer's instruction. The PCR failure rate of nucleic acids isolated from plasma samples using the MDx system was similar to that of plasma samples processed using the easyMAG system (2.0% and 3.1%, respectively). The PCR failure rate of nucleic acids isolated from urine samples using the MDx system was higher than that of urine samples processed using the easyMAG system (33.3% and 12.5%, respectively). These data suggest that the PCR inhibitors present in urine specimens are removed more efficiently by the easyMAG system. Among amplified specimens, the discordant results obtained from the two systems revealed that the BKV DNA load ranged from 2.3 log 10 copies/mL to 4.6 log 10 copies/mL. Of the 25 urine specimens that yielded BKV DNA by both extraction systems, 15 specimens (60.0%) yielded higher BKV DNA loads by the easyMAG system, indicating that the easyMAG system extracted nucleic acid more efficiently than did the MDx system. In conclusion, the easyMAG method outperformed the MDx method when used to extract BKV DNA from urine samples. Magnetic bead-based extraction methods such as the easyMAG system are therefore preferable for the quantitation of viral DNA in urine.

Identification of the novel KI and WU polyomaviruses in human tonsils

Background Three novel polyomaviruses have been recently discovered: KI, WU and MC polyomaviruses. Their role in human pathology is debated while tissue tropism and site of latency remain unknown. Objective To test the hypothesis that KI, WU and MC polyomaviruses can infect human tonsils. Study design Archival paraffin-embedded tonsils from 91 patients affected by different tonsil diseases were screened by polymerase chain reaction to detect viral DNA of KIV, WUV, MCV, BKV and JCV. Phylogenetic and evolutionary analysis of the identified polyomaviruses was carried out. Results Of the 91 tested specimens, 11 contained KIV DNA (12%), 4 WUV DNA (4.4%), 5 BKV DNA (5.5%). MCV and JCV were not detected. Phylogenetic analysis showed that KIVs identified in tonsils fall into a clade distinct from that containing KIVs isolated from respiratory secretions, respiratory tissue and feces. Moreover, four positively selected sites (4.5% of t-Ag sites) were found under strong positive selection ( ω = 11.4), with posterior probabilities above 0.99. All the sites were located in the N-terminal region of the small t antigen. Conclusions The results suggest that the novel KI and WU polyomaviruses can infect human tonsils. Future studies are needed to define their role in tonsil diseases.

Restriction of Human Polyomavirus BK Virus DNA Replication in Murine Cells and Extracts

BK virus (BKV) causes persistent and asymptomatic infections in most humans and is the etiologic agent of polyomavirus-associated nephropathy (PVAN) and other pathologies. Unfortunately, there are no animal models with which to study activation of BKV replication in the human kidney and the accompanying PVAN. Here we report studies of the restriction of BKV replication in murine cells and extracts and the cause(s) of this restriction. Upon infection of murine cells, BKV expressed large T antigen (TAg), but viral DNA replication and progeny were not detected. Transfection of murine cells with BKV TAg expression vectors also caused TAg expression without accompanying DNA replication. Analysis of the replication of DNAs containing chimeric BKV and murine polyomavirus origins revealed the importance of BKV core origin sequences and TAg for DNA replication. A sensitive assay was developed with purified BKV TAg that supported TAg-dependent BKV DNA replication with human but not with murine cell extracts. Addition of human replication proteins, DNA polymerase alpha-primase, replication protein A, or topoisomerase I to the murine extracts with BKV TAg did not rescue viral DNA replication. Notably, addition of murine extracts to human extracts inhibited BKV TAg-dependent DNA replication at a step prior to or during unwinding of the viral origin. These findings and differences in replication specificity between BKV TAg and the TAgs of simian virus 40 (SV40) and JC virus (JCV) and their respective origins implicate features of the BKV TAg and origin distinct from SV40 and JCV in restriction of BKV replication in murine cells.

Prevalence of polyomavirus viruria (JC virus/BK virus) in children following liver transplantation

BKV infection is a potential cause of renal dysfunction in non-renal organ transplant recipients. JCV is the causative agent of PML. Furthermore, polyomaviruses are tumor inducing viruses and molecular data suggest an association with malignancies among solid organ transplant patients. So far, there are no studies analyzing polyomavirus viruria following Ltx in children. We performed a prospective prevalence study at a mean of 2187 (range 20-5671) days after transplantation in 100 consecutive children admitted for the routine follow-up examination post-Ltx. The urine was screened for BKV and JCV DNA by using PCR in each case. A plasma analysis by PCR was also done if more than 100,000 DNA copies/mL urine were detected. BKV or JCV viruria was found in 19% (n = 19) of our patients. All patients were free of clinical signs of viral infection, PML, or nephropathy. GFR was normal in 97% of patients and we found no statistical difference of kidney function between patients with and without BKV/JCV viruria. The extent of immunosuppressive therapy had no influence on the polyomavirus viruria. Overall, we found a higher prevalence of polyomavirus viruria in our pediatric liver transplant recipients than reported in adult patients.

Lymphotropic Polyomavirus and Progressive Multifocal Leukoencephalopathy

We read with interest the fast-track communication by Delbue et al. on the possible involvement of lymphotropic polyomavirus (LPV) in leukoencephalopathies occurring in human immunodeficiency virus (HIV)-positive individuals (2). We are especially interested in the positive LPV PCR of peripheral blood mononuclear cells (PBMCs) collected from an HIV-positive patient with progressive multifocal leukoencephalopathy (PML). We wonder whether in this patient the diagnosis of PML was histology proven, i.e., supported by positive JC polyomavirus (JCV) PCR or JCV immunohistochemistry on brain biopsy. Although PML lesions are usually positive for JCV DNA only, rare cases exclusively associated (4) or coassociated (3) with the other polyomavirus, BKV, have been reported, and some authors estimate that BKV DNA is found in PML 10-fold less frequently than JCV DNA (6). In PBMCs, the other polyomaviruses have a very high prevalence in HIV-positive patients: e.g., Degener et al. found JCV in PBMCs from 22.8% of cases and BKV in PBMCs from 51.1% of cases, making their association with leukoencephalopathies quite poor (1). Thus, in our opinion, it would be very helpful to compare the prevalence of LPV DNA in brain biopsies from patients with leukoencephalopathies and healthy controls. Although Perez-Liz et al. recently questioned the positive predictive value of JCV PCR in brain biopsies for the diagnosis of PML (5), we reason that the demonstration of LPV DNA in brain biopsies would be a prerequisite step for satisfying Koch postulates.

Increased prevalence of polyomavirus BK viruria that correlates with thrombocytopenia in patients with systemic lupus erythematosus on intensive immunosuppressive therapy

The prevalence of polyomavirus BK (BKV) reactivation is high in patients with systemic lupus erythematosus (SLE) on long-term immunosuppressants compared to normal population. However, only a few studies are available for the possible correlation of BKV reactivation and clinical manifestations in SLE patients. In the present study, we tried to correlate BKV viruria, clinical manifestations, laboratory findings, and medications in patients with SLE. The urine BKV viral DNA copies were detected from 95 patients with SLE and 32 healthy volunteers by real-time PCR. We found that the prevalence rate of BKV viruria in SLE patients was significantly higher than normal group (71.6% vs. 18.6%, p < 0.001) as well as the urine BKV DNA viral load (4.74 ± 3.17 vs. 1.08 ± 2.33 by log scale, p < 0.001). Interestingly, BKV viruria (+) SLE patients had more thrombocytopenic events than BKV viruria ( − ) group (32.4% vs. 3.7%, p = 0.008 after adjustment by age and sex). The patients with BKV viruria DNA copy number >3,200,000/ml exhibited more thrombocytopenia risk than BKV viruria ≦3,200,000 copy number/ml or BKV viruria ( − ). The use of potent immunosuppressants may increase BKV viruria. In a refractory thrombocytoponeic case, the add-on of anti-BKV medication, leflunomide 20 mg/day rapidly decreased BKV viruria and recovered platelet counts. In conclusion, our study demonstrated that patients with SLE had higher prevalence rate of BKV reactivation that is correlated with thrombocytopenic episode. Intensive immunosuppressive therapy in SLE may increase the risk of BKV viruria.

P.042 Comparative analysis of two Adenovirus TaqMan PCRs

Three novel polyomaviruses have been recently discovered: KI, WU and MC polyomaviruses. Their role in human pathology is debated while tissue tropism and site of latency remain unknown.To test the hypothesis that KI, WU and MC polyomaviruses can infect human tonsils.Archival paraffin-embedded tonsils from 91 patients affected by different tonsil diseases were screened by polymerase chain reaction to detect viral DNA of KIV, WUV, MCV, BKV and JCV. Phylogenetic and evolutionary analysis of the identified polyomaviruses was carried out.Of the 91 tested specimens, 11 contained KIV DNA (12%), 4 WUV DNA (4.4%), 5 BKV DNA (5.5%). MCV and JCV were not detected. Phylogenetic analysis showed that KIVs identified in tonsils fall into a clade distinct from that containing KIVs isolated from respiratory secretions, respiratory tissue and feces. Moreover, four positively selected sites (4.5% of t-Ag sites) were found under strong positive selection (ω = 11.4), with posterior probabilities above 0.99. All the sites were located in the N-terminal region of the small t antigen.The results suggest that the novel KI and WU polyomaviruses can infect human tonsils. Future studies are needed to define their role in tonsil diseases.

Early Diagnosis of Polyomavirus Type BK Infection in Tailoring Immunosuppression for Kidney Transplant Patients: Screening With Urine Qualitative Polymerase Chain Reaction Assay

Polyomavirus type BK (BKV) nephropathy is increasingly a significant cause of graft dysfunction and even failure. Early diagnosis followed by reduction of immunosuppression has been associated with an improved prognosis. We screened 250 patients with the urine qualitative polymerase chain reaction (PCR) for BKV DNA. We followed with blood BKV PCR if the urine screen was positive and then reduced immunosuppression in viremic patients. One hundred ninety-nine patients (80%) had no viuria; 43 (17%) viuria; and 8 (3%) both viuria and viremia. Graft biopsy performed in three patients (1%) with viremia and impaired graft function all revealed BKV nephropathy. After 6 months of follow-up, seven out of eight viremic patients (88%) had negative repeat blood PCR and stabilized graft function. An early diagnosis of BKV infection with reduction of immunosuppression may reverse viremia and retard progression of BKV nephropathy. BKV screening by PCR assays should be considered in kidney transplant recipients, especially those with impaired graft function.

Cidofovir Inhibits Polyomavirus BK Replication in Human Renal Tubular Cells Downstream of Viral Early Gene Expression

The human polyomavirus BK (BKV) causes nephropathy and hemorrhagic cystitis in kidney and bone marrow transplant patients, respectively. The anti-viral cidofovir (CDV) has been used in small case series but the effects on BKV replication are unclear, since polyomaviruses do not encode viral DNA polymerases. We investigated the effects of CDV on BKV(Dunlop) replication in primary human renal proximal tubule epithelial cells (RPTECs). CDV inhibited the generation of viral progeny in a dose-dependent manner yielding a 90% reduction at 40 microg/mL. Early steps such as receptor binding and entry seemed unaffected. Initial large T-antigen transcription and expression were also unaffected, but subsequent intra-cellular BKV DNA replication was reduced by >90%. Late viral mRNA and corresponding protein levels were also 90% reduced. In uninfected RPTECs, CDV 40 microg/mL reduced cellular DNA replication and metabolic activity by 7% and 11% in BrdU and WST-1 assays, respectively. BKV infection increased DNA replication to 142% and metabolic activity to 116%, respectively, which were reduced by CDV 40 microg/mL to levels of uninfected untreated RPTECs. Our results show that CDV inhibits BKV DNA replication downstream of large T-antigen expression and involves significant host cell toxicity. This should be considered in current treatment and drug development.

Monitoring of BK virus replication in the first year following renal transplantation

BK virus-associated nephropathy (BKVAN) is one of the most common viral diseases affecting renal allografts. Screening for viral replication may allow for earlier intervention with reduced allograft loss. A plasma viral load >10(4) copies/mL of BKV DNA is recommended for a presumed diagnosis of BKVAN. We monitored BKV load on serum and urine samples by Real-Time TaqMan PCR in 229 renal transplant recipients in the first year post-transplantation. Overall, 2025 serum and 2025 urine samples were evaluated. A graft biopsy was performed in 47/229 patients to investigate the declining renal function. Operating characteristics [sensitivity, specificity, negative predictive value (NPV), positive predictive value (PPV)] and receiver operating characteristic (ROC) curve analysis at different viral load values were calculated. Serum BKV viral load was >10(4) in 5/229 patients (2.2%). A histological diagnosis of BKVAN was made in 3/229 patients (1.3%): 3/5 (60.0%) among those with serum viral load >10(4) and 3/4 (75.0%) in those with >1.6 x 10(4). Operating characteristics of a serum BK load of 10(4) for the diagnosis of BKVAN were as follows: sensitivity, 100%; specificity, 99.1%; NPV, 100%; PPV, 59.4%. Specificity and PPV rose to 99.6% and 75.0% when using a cut-off level of 1.6 x 10(4) copies/mL. The recommended level of BK viraemia of 10(4) copies/mL is useful to identify patients at risk of BKVAN, although specificity and PPV increase by using a cut-off level of 1.6 x 10(4) copies/mL. BK replication may occur in the first 3 months post-transplantation and subsequently recede. Therefore, the temporal profile of BKV replication has to be accurately evaluated and occasionally elevated values should prompt a closer monitoring.

The use of unprocessed urine samples for detecting and monitoring BK viruses in renal transplant recipients by a quantitative real-time PCR assay

Results of quantitative BK viral load using real-time quantitative PCR (rt-QPCR) were compared using two types of samples, extracted urine DNA and unprocessed urine. An excellent correlation was observed in quantitative viral load between unprocessed urine and extracted urine DNA samples. ( R 2 = 0.96, p < 0.001). Compared to extracted urine DNA when a small sample volume of unprocessed urine was used (2 μl per PCR reaction), 100% concordance is detection of BKV DNA was observed in 124 samples (106 positive and 18 negative) collected from renal transplant recipient (RTR). There was no significant difference in the quantitative BK viral load (log 10 copies/ml) detected in extracted urine DNA (median = 7.82) compared to unprocessed urine (median = 7.17). Urine pH in the range of 5.2–7.1 and specimen freezing had no effect on the rt-QPCR reaction. The partial inhibition of the rt-QPCR reaction observed when 5 μl sample volume of unprocessed urine was used was markedly reduced at a sample volume of 2 μl. Using unprocessed urine for rt-QPCR detection of BK viral load is cost-saving while maintaining the sensitivity and accuracy associated with the use of extracted urine DNA, making a clinical BKV surveillance strategy in RTR based on urinary sample screening using rt-QPCR as the first line test more feasible.

JCV and BKV prevalence in people infected with HIV-1

Human pathogenic viruses of the polyoma type were discovered only in the 70s of the 20th century. So far seroepidemiologic researches concerning these infections have been carried out on small groups and probably are not representative of the entire of population. They showed a past polyomaviruses infection in 35–85% people in a healthy population. In two cases: JSV and BKV reactivation plays a role in a development of diseases in people with impaired immunological response, e.g. HIV infection history. The aim of the study was to examine the frequency of prevalence of JCV and BKV in various body fluids and pathogenicity connected with these viruses in patients infected with HIV-1. The tests included 108 people of both sexes, in whom HIV-1 infection was diagnosed. JCV/BKV infection was diagnosed in 27 (25%) HIV-1 infected patients, where JCV constituted 18 (16.7%) cases and 9 (8.3%) BKV. The infections were proven on the basis of a presence of virus genetic material in urine. In none of the patients was JCV and BKV detected in blood and cerebrospinal fluid. In the patient group with TCD4 lymphocyte count < 200 cell/μL JCV DNA was detected in urine in 5 (11.4%), and BKV in 7 (15.9%) cases, in turn in the group of people with neurological conditions JCV in 3 (15%) and BKV also in 3 (15%) cases, (together in 6 (40%) people). Among the tested people with lymphocyte TCD4 lymphocyte count > 500 cell/μL JCV DNA was detected in urine in 9 (20.5%) cases and BKV DNA in 1 (2,3%) case.