Frequency and subtype of BK virus infection in Iranian patients infected with HIV

BK virus characterisation among HIV-1-Infected individuals and its association with immunosuppression

Purpose

BK virus (BKV) is an opportunistic pathogen which causes significant morbidity and mortality in individuals who are immunodeficient. We aimed to quantitate and characterise BKV and to correlate with the degree of immunosuppression among human immunodeficiency virus (HIV)-1-infected individuals.

Methods

BKV DNA detection was carried out using an in-house quantitative real-time polymerase chain reaction on paired whole-blood and urine samples collected from 187 antiretroviral therapy (ART)-naïve HIV-1-infected individuals and 93 healthy individuals who served as controls. Sequencing was performed for a proportion of high BK viral load (VL) samples to observe non-coding control region (NCCR) rearrangements.

Results

BKV positivity in urine was 25.6% among HIV-infected individuals and 10.7% in control individuals (P = 0.03). The BK VL showed a significant negative correlation with CD4+ T-cell counts, a positive correlation with WHO clinical staging and no significant correlation with HIV-1 VL. Of 42 BKVs from urine samples sequenced, two showed rearrangements without clinically severe disease or high VL. Their NCCR and VP1 sequence-based genotyping revealed genotype I. In a small subset of individuals (n = 8) on ART who were being followed up, six individuals showed either decrease or complete clearance of virus with ART.

Conclusion

There was a higher frequency of BK viruria in HIV-1-infected individuals than among healthy controls and the positivity correlated with the degree of immunosuppression. There was no association of high VL with NCCR rearrangements in urine.

The prevalence and isolated subtypes of BK polyomavirus reactivation among patients infected with human immunodeficiency virus-1 in southeastern China

BK polyomavirus (BKPyV) is an opportunistic infectious pathogen that is associated with hemorrhagic cystitis and nephropathy, mainly in transplant recipients and human immunodeficiency virus 1 (HIV-1) infected patients. However, molecular characterization studies of BKPyV in China are rare. This study was designed to elucidate the prevalence and to determine the main subtypes of BKPyV among HIV-1-infected patients in southeastern China. In addition, the increased incidences for BKPyV reactivation were analyzed. The isolated BKPyV DNA was amplified by polymerase chain reaction (PCR) and the specimen sequences were aligned with the reference sequences for phylogenetic analysis. In this study, BKPyV viruria was detected in 64.2% (88/137) of HIV-1-infected patients. Patients in the BKPyV-positive group were more diverse with respect to gender (P = 0.039) and age (P = 0.023) than their counterparts in the BKPyV-negative group, and they had a higher rate of co-infection with tuberculosis (TB) (P = 0.026). Viruria was more commonly found in patients with CD4 counts <200 cells/mm (72.7%) than in those with CD4 counts ≥200 cells/mm (58.5%) (not significant). All sequenced BKPyV isolates belonged to subtype I (13/32) and IV (19/32). A high prevalence of BKPyV reactivation was discovered in patients with HIV-1 infection. Females and elderly individuals, as well as those with a TB co-infection, appeared more susceptible to BKPyV reactivation in this study. BKPyV viruria was found more often and was associated with lower CD4 counts.

Human polyomavirus and human papillomavirus prevalence and viral load in non-malignant tonsillar tissue and tonsillar carcinoma

Human papillomaviruses (HPVs) are an acknowledged cause of a subset of oropharyngeal cancers, especially of tonsillar cancer. Similar to HPV, some human polyomaviruses (HPyVs), such as Merkel cell polyomavirus (MCPyV), have an oncogenic potential. Recently, several novel HPyVs have been discovered. The aim of our study was to determine viral DNA prevalence and viral DNA load of 13 different HPyVs in benign and malignant tonsillar tissue and to compare the data with those found for HPV. A total of 78 biopsies of palatine tonsils with a histologic diagnosis of non-malignant disease (chronic tonsillitis, tonsillar hyperplasia, n = 40) or tonsillar squamous cell carcinoma (n = 38) were included in the study. HPyV DNA prevalence and viral load were determined by virus-specific quantitative real-time PCRs. JCPyV (1/40, 2.5%) and WUPyV (3/40, 7.5%) were only found in non-malignant tonsillar tissue. HPyV7 and HPyV10 were only detected in one (2.6%) and seven (18.4%) of the 38 cancer biopsies, respectively. Both MCPyV (8/38, 21.1 vs. 4/40, 10.0%) and HPyV6 (2/38, 5.3 vs. 1/40, 2.5%) were found more frequently in cancer samples than in non-malignant tissue, but the differences were not significant. BKPyV, KIPyV, TSPyV, HPyV9, STLPyV, HPyV12 and NJPyV were not discovered in any of the samples. HPyV loads found in HPyV DNA-positive biopsies were very low with no difference between non-malignant and malignant samples (median load <0.0001 HPyV DNA copies per beta-globin gene copy, respectively). In contrast to HPyV, high-risk HPV types (HPV16/HPV18) were found significantly more frequently in tonsillar cancers than in non-malignant tonsillar tissue (17/38, 44.7 vs. 2/40, 5.0%, p < 0.001). Furthermore, high-risk HPV DNA loads were significantly higher in the cancer compared to the non-malignant samples (median load 11.861 vs. 7 × 10^-6 HPV DNA copies per beta-globin gene copy, p = 0.012). While both HPV and HPyV may persist in tonsillar tissue, our data on HPyV DNA prevalence and load do not support a role of HPyV in tonsillar carcinogenesis, neither alone nor as co-infecting agents of HPV.

BK nephropathy in the native kidneys of patients with organ transplants: Clinical spectrum of BK infection

Nephropathy secondary to BK virus, a member of the Papoviridae family of viruses, has been recognized for some time as an important cause of allograft dysfunction in renal transplant recipients. In recent times, BK nephropathy (BKN) of the native kidneys has being increasingly recognized as a cause of chronic kidney disease in patients with solid organ transplants, bone marrow transplants and in patients with other clinical entities associated with immunosuppression. In such patients renal dysfunction is often attributed to other factors including nephrotoxicity of medications used to prevent rejection of the transplanted organs. Renal biopsy is required for the diagnosis of BKN. Quantitation of the BK viral load in blood and urine are surrogate diagnostic methods. The treatment of BKN is based on reduction of the immunosuppressive medications. Several compounds have shown antiviral activity, but have not consistently shown to have beneficial effects in BKN. In addition to BKN, BK viral infection can cause severe urinary bladder cystitis, ureteritis and urinary tract obstruction as well as manifestations in other organ systems including the central nervous system, the respiratory system, the gastrointestinal system and the hematopoietic system. BK viral infection has also been implicated in tumorigenesis. The spectrum of clinical manifestations from BK infection and infection from other members of the Papoviridae family is widening. Prevention and treatment of BK infection and infections from other Papovaviruses are subjects of intense research.