Bovine Polyomavirus-1 (Epsilonpolyomavirus bovis): An Emerging Fetal Pathogen of Cattle That Causes Renal Lesions Resembling Polyomavirus-Associated Nephropathy of Humans.

Bovine polyomavirus-1 (BoPyV-1, Epsilonpolyomavirus bovis) is widespread in cattle and has been detected in commercialized beef at supermarkets in the USA and Germany. BoPyV-1 has been questioned as a probable zoonotic agent with documented increase in seropositivity in people exposed to cattle. However, to date, BoPyV-1 has not been causally associated with pathology or disease in any animal species, including humans. Here we describe and illustrate pathological findings in an aborted bovine fetus naturally infected with BoPyV-1, providing evidence of its pathogenicity and probable abortigenic potential. Our results indicate that: (i) BoPyV-1 can cause severe kidney lesions in cattle, including tubulointerstitial nephritis with cytopathic changes and necrosis in tubular epithelial cells, tubular and interstitial inflammation, and interstitial fibroplasia; (ii) lesions are at least partly attributable to active viral replication in renal tubular epithelial cells, which have abundant intranuclear viral inclusions; (iii) BoPyV-1 large T (LT) antigen, resulting from early viral gene expression, can be detected in infected renal tubular epithelial cells using a monoclonal antibody raised against Simian Virus-40 polyomavirus LT antigen; and (iv) there is productive BoPyV-1 replication and virion assembly in the nuclei of renal tubular epithelial cells, as demonstrated by the ultrastructural observation of abundant arrays of viral particles with typical polyomavirus morphology. Altogether, these lesions resemble the "cytopathic-inflammatory pathology pattern" proposed in the pathogenesis of Human polyomavirus-1-associated nephropathy in immunocompromised people and kidney allograft recipients. Additionally, we sequenced the complete genome of the BoPyV-1 infecting the fetus, which represents the first whole genome of a BoPyV-1 from the Southern Hemisphere. Lastly, the BoPyV-1 strain infecting this fetus was isolated, causing a cytopathic effect in Madin-Darby bovine kidney cells. We conclude that BoPyV-1 is pathogenic to the bovine fetus under natural circumstances. Further insights into the epidemiology, biology, clinical relevance, and zoonotic potential of BoPyV-1 are needed.

BK Polyomavirus-associated nephropathy managed by screening policy in a real-life setting.

BACKGROUND: BK polyomavirus-associated nephropathy (PyVAN) is an important complication after kidney transplantation. Prevalence ranges from 1% to 10%, and graft loss occurs in approximately 50% of the cases. There is no effective treatment, so early viral detection with immunosuppression tapering is the current strategy to prevent PyVAN. AIMS: To verify the frequency of PyVAN in a single center and evaluate the response to immunosuppressive adjustments through graft survival analysis. METHODS: Retrospective evaluation of a cohort of kidney transplant recipients with biopsy-proven PyVAN, compared with no-PyVAN patients regarding clinical aspects, immunosuppression, and graft survival over at least 2 years. RESULTS: There were 1404 kidney transplants analyzed in the study period, 58 with biopsy-proven PyVAN. Cumulative incidence was 4.1%. Median time from transplantation to PyVAN diagnosis was 6 (1-41) months. PyVAN was associated with recipient male gender (P = .041) and deceased donation (P = .005). Graft survival was inferior for PyVAN compared to no-PyVAN patients, 81.8% vs 75.2%, P = .019. Thirteen (22.4%) PyVAN patients lost their grafts, nine (15.5%) losses attributed to BKPyV infection. Three patients with BKPyV-associated graft losses were submitted to a successful second kidney transplant, with no evidence of viral replication during follow-up. CONCLUSION: PyVAN still is an important cause of kidney graft failure. Even though implementing active vigilance and immunosuppressive adjustment, this real-life single-center study demonstrated inferior graft survival in PyVAN patients compared to non-PyVAN.

Evaluation of the predisposition and clinical impact of BK virus replication in kidney transplant patients.

The BK virus (BKV) produces a subclinical kidney infection in immunocompetent individuals. However, viremia may occur in kidney transplant patients with ongoing immunosuppression. BKV-associated nephropathy (BKVN) has no specific treatment and is a leading cause of organ transplant loss. In this study, we evaluated the predisposition and the clinical impact of BKV replication in kidney transplant patients during post-transplant monitoring in a reference institution in Brazil. Demographic, clinical and laboratory data generated during routine outpatient follow-up were retrospectively collected. BK viremia was investigated using real-time polymerase chain reaction. Of the 553 participants, 7.4% (n = 41) presented BKV replication. Of these, 16 (39%) lost their kidney graft and interstitial nephritis was identified on kidney biopsy in 50% of the cases. Among the evaluated variables, only the use of the immunosuppressant mycophenolate sodium was identified as a risk factor for viremia (OR 7.96; 95% CI 2.35 to 26.98). The graft survival estimate in BKV-positive patients was significantly reduced (24.8% vs. 85.6%) after 10 years of transplantation. We concluded that defining predisposing factors remains an important challenge for the prevention and control of BKV activity following kidney transplantation, especially considering the development of BKVN and its strong effect on graft maintenance.

Evaluation of the predisposition and clinical impact of BK virus replication in kidney transplant patients

ABSTRACT The BK virus (BKV) produces a subclinical kidney infection in immunocompetent individuals. However, viremia may occur in kidney transplant patients with ongoing immunosuppression. BKV-associated nephropathy (BKVN) has no specific treatment and is a leading cause of organ transplant loss. In this study, we evaluated the predisposition and the clinical impact of BKV replication in kidney transplant patients during post-transplant monitoring in a reference institution in Brazil. Demographic, clinical and laboratory data generated during routine outpatient follow-up were retrospectively collected. BK viremia was investigated using real-time polymerase chain reaction. Of the 553 participants, 7.4% (n = 41) presented BKV replication. Of these, 16 (39%) lost their kidney graft and interstitial nephritis was identified on kidney biopsy in 50% of the cases. Among the evaluated variables, only the use of the immunosuppressant mycophenolate sodium was identified as a risk factor for viremia (OR 7.96; 95% CI 2.35 to 26.98). The graft survival estimate in BKV-positive patients was significantly reduced (24.8% vs. 85.6%) after 10 years of transplantation. We concluded that defining predisposing factors remains an important challenge for the prevention and control of BKV activity following kidney transplantation, especially considering the development of BKVN and its strong effect on graft maintenance.

Polyomavirus-associated nephropathy in renal and simultaneous pancreas-kidney transplant recipients: report of three cases.

Infection with polyomavirus (BK virus) is the cause of renal graft losses in more than 50% of the infected cases. There should be a high index of suspicion about this disease, although the incidence is only between 2% and 5% as the future of renal graft depends on the early and appropriate management of the same. Herein, we describe three clinical cases: Two were those of kidney transplant and the third, a combined kidney-pancreas transplant. In these cases, by reducing immunosuppression and, in one case, replacing the calcineurin inhibitor by MTOR (mammalian target of rapamycin) in addition, we were able to preserve of the normal function of the transplanted organs.

Prevalence of HMTV in breast carcinomas and unaffected tissue from Mexican women.

BACKGROUND: Breast cancer is a complex multifactorial genetic disease. Among other factors, race and, to an even greater extent, viruses are known to influence the development of this heterogeneous disease. It has been reported that MMTV-like (HMTV) gene sequences with a 90 to 98% homology to mouse mammary tumor virus are found in several populations with a prevalence range of 0 to 74%. In the Mexican population, 4.2% of patients with breast cancer exhibit the presence of HMTV (MMTV-like) sequences. The aim of this study was to evaluate the presence and current prevalence of retroviral HMTV (MMTV-like) sequences in breast cancer in Mexican women. METHODS: We used nested PCR and real-time PCR with a TaqMan probe. As a positive control, we used the C3H MMTV strain inserted into pBR322 plasmid. To confirm that we had identified the HMTV sequences, we sequenced the amplicons and compared these sequences with those of MMTV and HMTV (GenBank AF033807 and AF346816). RESULTS: A total of 12.4% of breast tumors were HMTV-positive, and 15.7% of the unaffected tissue samples from 458 patients were HMTV-positive. A total of 8.3% of the patients had both HMTV-positive tumor and adjacent tissues. The HMTV-positive samples presented 98% similarity to the reported HMTV sequence. CONCLUSIONS: These results confirm that the HMTV sequence is present in breast tumors and non-affected tissues in the Mexican population. HMTV should be considered a prominent causative agent of breast cancer.

Human papillomavirus detection in women with and without human immunodeficiency virus infection in Colombia.

BACKGROUND: HIV infection leads to a decreasing immune response, thereby facilitating the appearance of other infections, one of the most important ones being HPV. However, studies are needed for determining associations between immunodeficiency caused by HIV and/or the presence of HPV during the course of cervical lesions and their degree of malignancy. This study describes the cytological findings revealed by the Papanicolaou test, laboratory characteristics and HPV molecular profile in women with and without HIV infection. METHODS: A total of 216 HIV-positive and 1,159 HIV-negative women were invited to participate in the study; PCR was used for the molecular detection of HPV in cervical samples. Statistical analysis (such as percentages, Chi-square test and Fisher's exact test when applicable) determined human papillomavirus (HPV) infection frequency (single and multiple) and the distribution of six types of high-risk-HPV in women with and without HIV infection. Likewise, a logistic regression model was run to evaluate the relationship between HIV-HPV infection and different risk factors. RESULTS: An association was found between the frequency of HPV infection and infection involving 2 or more HPV types (also known as multiple HPV infection) in HIV-positive women (69.0% and 54.2%, respectively); such frequency was greater than that found in HIV-negative women (44.3% and 22.7%, respectively). Statistically significant differences were observed between both groups (p = 0.001) regarding HPV presence (both in infection and multiple HPV infection). HPV-16 was the most prevalent type in the population being studied (p = 0.001); other viral types had variable distribution in both groups (HIV-positive and HIV-negative). HPV detection was associated with <500 cell/mm(3) CD4-count (p = 0.004) and higher HIV-viral-load (p = 0.001). HPV-DNA detection, <200 cell/mm(3) CD4-count (p = 0.001), and higher HIV-viral-load (p = 0.001) were associated with abnormal cytological findings. CONCLUSIONS: The HIV-1 positive population in this study had high multiple HPV infection prevalence. The results for this population group also suggested a greater association between HPV-DNA presence and cytological findings. HPV detection, together with low CD4 count, could represent useful tools for identifying HIV-positive women at risk of developing cervical lesions.

No association between Epstein-Barr Virus and Mouse Mammary Tumor Virus with breast cancer in Mexican women.

Breast cancer is the most frequent malignancy affecting women worldwide. It has been suggested that infection by Epstein Barr Virus (EBV), Mouse Mammary Tumor Virus or a similar virus, MMTV-like virus (MMTV-LV), play a role in the etiology of the disease. However, studies looking at the presence of these viruses in breast cancer have produced conflicting results, and this possible association remains controversial. Here, we used polymerase chain reaction assay to screen specific sequences of EBV and MMTV-LV in 86 tumor and 65 adjacent tissues from Mexican women with breast cancer. Neither tumor samples nor adjacent tissue were positive for either virus in a first round PCR and only 4 tumor samples were EBV positive by a more sensitive nested PCR. Considering the study's statistical power, these results do not support the involvement of EBV and MMTV-LV in the etiology of breast cancer.

JC polyomavirus infection in candidates for kidney transplantation living in the Brazilian Amazon region.

This study evaluated the relative occurrences of BK virus (BKV) and JC virus (JCV) infections in patients with chronic kidney disease (CKD). Urine samples were analysed from CKD patients and from 99 patients without CKD as a control. A total of 100 urine samples were analysed from the experimental (CKD patients) group and 99 from the control group. Following DNA extraction, polymerase chain reaction (PCR) was used to amplify a 173 bp region of the gene encoding the T antigen of the BKV and JCV. JCV and BKV infections were differentiated based on the enzymatic digestion of the amplified products using BamHI endonuclease. The results indicated that none of the patients in either group was infected with the BKV, whereas 11.1% (11/99) of the control group subjects and 4% (4/100) of the kidney patients were infected with the JCV. High levels of urea in the excreted urine, low urinary cellularity, reduced bladder washout and a delay in analysing the samples may have contributed to the low prevalence of infection. The results indicate that there is a need to increase the sensitivity of assays used to detect viruses in patients with CDK, especially given that polyomavirus infections, especially BKV, can lead to a loss of kidney function following transplantation.

JC polyomavirus infection in candidates for kidney transplantation living in the Brazilian Amazon Region

This study evaluated the relative occurrences of BK virus (BKV) and JC virus (JCV) infections in patients with chronic kidney disease (CKD). Urine samples were analysed from CKD patients and from 99 patients without CKD as a control. A total of 100 urine samples were analysed from the experimental (CKD patients) group and 99 from the control group. Following DNA extraction, polymerase chain reaction (PCR) was used to amplify a 173 bp region of the gene encoding the T antigen of the BKV and JCV. JCV and BKV infections were differentiated based on the enzymatic digestion of the amplified products using BamHI endonuclease. The results indicated that none of the patients in either group was infected with the BKV, whereas 11.1% (11/99) of the control group subjects and 4% (4/100) of the kidney patients were infected with the JCV. High levels of urea in the excreted urine, low urinary cellularity, reduced bladder washout and a delay in analysing the samples may have contributed to the low prevalence of infection. The results indicate that there is a need to increase the sensitivity of assays used to detect viruses in patients with CDK, especially given that polyomavirus infections, especially BKV, can lead to a loss of kidney function following transplantation.

Prevalence of infection by JC and BK polyomaviruses in kidney transplant recipients and patients with chronic renal disease.

The present study investigated the prevalence of infection by JC and BK polyomaviruses (JCV and BKV) in patients with chronic renal disease (CRD), kidney transplant recipients, and a control group of asymptomatic subjects. We tested a total of 295 urine samples. After DNA extraction, polymerase chain reaction assay was used to amplify a fragment of 173 bp of the polyomavirus T antigen, followed by analysis using the BamHI restriction endonuclease. Infection by polyomavirus was detected in 17.6% (52/295 subjects) of the subjects. Whereas 30.5% (18/59) of transplant recipients were infected, the frequency was only 22.4% (30/134) in the control subjects, and 3.9% (4/102) in the CRD group (all JCV). The vast majority of infections (88.9%; 16/18) in transplant recipients were of the BKV type, whereas this type was absent in CRD patients, and made up only 10.0% (3/30) of infections in the control group. The risk of BKV infection was 72 times greater in renal transplant patients than in asymptomatic subjects. The low frequency of infection found in CRD patients may have been related to elevated levels of urea excreted in the urine, together with reduced urine volume and cell content. These factors may combine to reduce viral load or inhibit amplification. The results of the study indicate a need for the routine screening for polyomavirus in pre- and post-transplant patients, as well as organ donors, considering that BKV infection has been associated with graft rejection in kidney transplants.

Identification of viral infections in the prostate and evaluation of their association with cancer.

BACKGROUND: Several viruses with known oncogenic potential infect prostate tissue, among these are the polyomaviruses BKV, JCV, and SV40; human papillomaviruses (HPVs), and human cytomegalovirus (HCMV) infections. Recently, the Xenotropic Murine Leukemia Virus-related gammaretrovirus (XMRV) was identified in prostate tissue with a high prevalence observed in prostate cancer (PC) patients homozygous for the glutamine variant of the RNASEL protein (462Q/Q). Association studies with the R462Q allele and non-XMRV viruses have not been reported. We assessed associations between prostate cancer, prostate viral infections, and the RNASEL 462Q allele in Mexican cancer patients and controls. METHODS: 130 subjects (55 prostate cancer cases and 75 controls) were enrolled in the study. DNA and RNA isolated from prostate tissues were screened for the presence of viral genomes. Genotyping of the RNASEL R462Q variant was performed by Taqman method. RESULTS: R/R, R/Q, and Q/Q frequencies for R462Q were 0.62, 0.38, and 0.0 for PC cases and 0.69, 0.24, and 0.07 for controls, respectively. HPV sequences were detected in 11 (20.0%) cases and 4 (5.3%) controls. XMRV and HCMV infections were detected in one and six control samples, respectively. The risk of PC was significantly increased (Odds Ratio = 3.98; 95% CI: 1.17-13.56, p = 0.027) by infection of the prostatic tissue with HPV. BKV, JCV, and SV40 sequences were not detected in any of the tissue samples examined. CONCLUSIONS: We report a positive association between PC and HPV infection. The 462Q/Q RNASEL genotype was not represented in our PC cases; thus, its interaction with prostate viral infections and cancer could not be evaluated.

Impact of human papillomavirus (HPV)-6/11/16/18 vaccine on all HPV-associated genital diseases in young women.

BACKGROUND: The impact of the prophylactic vaccine against human papillomavirus (HPV) types 6, 11, 16, and 18 (HPV6/11/16/18) on all HPV-associated genital disease was investigated in a population that approximates sexually naive women in that they were "negative to 14 HPV types" and in a mixed population of HPV-exposed and -unexposed women (intention-to-treat group). METHODS: This analysis studied 17 622 women aged 15-26 years who were enrolled in one of two randomized, placebo-controlled, efficacy trials for the HPV6/11/16/18 vaccine (first patient on December 28, 2001, and studies completed July 31, 2007). Vaccine or placebo was given at day 1, month 2, and month 6. All women underwent cervicovaginal sampling and Papanicolaou (Pap) testing at day 1 and every 6-12 months thereafter. Outcomes were any cervical intraepithelial neoplasia; any external anogenital and vaginal lesions; Pap test abnormalities; and procedures such as colposcopy and definitive therapy. Absolute rates are expressed as women with endpoint per 100 person-years at risk. RESULTS: The average follow-up was 3.6 years (maximum of 4.9 years). In the population that was negative to 14 HPV types, vaccination was up to 100% effective in reducing the risk of HPV16/18-related high-grade cervical, vulvar, and vaginal lesions and of HPV6/11-related genital warts. In the intention-to-treat group, vaccination also statistically significantly reduced the risk of any high-grade cervical lesions (19.0% reduction; rate vaccine = 1.43, rate placebo = 1.76, difference = 0.33, 95% confidence interval [CI] = 0.13 to 0.54), vulvar and vaginal lesions (50.7% reduction; rate vaccine = 0.10, rate placebo = 0.20, difference = 0.10, 95% CI = 0.04 to 0.16), genital warts (62.0% reduction; rate vaccine = 0.44, rate placebo = 1.17, difference = 0.72, 95% CI = 0.58 to 0.87), Pap abnormalities (11.3% reduction; rate vaccine = 10.36, rate placebo = 11.68, difference = 1.32, 95% CI = 0.74 to 1.90), and cervical definitive therapy (23.0% reduction; rate vaccine = 1.97, rate placebo = 2.56, difference = 0.59, 95% CI = 0.35 to 0.83), irrespective of causal HPV type. CONCLUSIONS: High-coverage HPV vaccination programs among adolescents and young women may result in a rapid reduction of genital warts, cervical cytological abnormalities, and diagnostic and therapeutic procedures. In the longer term, substantial reductions in the rates of cervical, vulvar, and vaginal cancers may follow.

[Focal segmental glomerulosclerosis related to BK virus in a child with nephrotic syndrome. A case report]. / Glomerulopatía colapsante asociada a virus BK en un niño con síndrome nefrótico idiopático. Informe de un caso.

BACKGROUND: focal segmental glomerulosclerosis (FSGS) is observed in about 10 % of children with idiopathic nephrotic syndrome; this disorder is usually resistant to corticoid therapy. In the last few years, five histological types of FSGS have been recognized; the collapsing nephropathy type is characterized by a rapid evolution to chronic renal failure. CLINICAL CASE: a four-year-old boy presented with an irrelevant past history; eight months before admission he developed idiopathic nephrotic syndrome. He was treated with steroids without improvement, and a renal biopsy was performed in which minimal glomerular changes were found. Despite combined immunosuppressive treatment, he developed renal failure, septic shock and death. Collapsing nephropathy was demonstrated by immunohistochemistry, light and electron microscopy; renal new human papovirus (BK) infection was also found in the postmortem study. CONCLUSIONS: collapsing nephropathy is an aggressive disorder resistant to immunosuppressive treatment, as occurred in our patient. Although some viral diseases have been associated with collapsing nephropathy, to our knowledge, BK infection has not been previously described in those patients.

Neither one-time negative screening tests nor negative colposcopy provides absolute reassurance against cervical cancer.

A population sample of 10,049 women living in Guanacaste, Costa Rica, was recruited into a natural history of human papillomavirus (HPV) and cervical neoplasia study in 1993-1994. At the enrollment visit, we applied multiple state-of-the-art cervical cancer screening methods to detect prevalent cervical cancer and to prevent subsequent cervical cancers by the timely detection and treatment of precancerous lesions. Women were screened at enrollment with 3 kinds of cytology (often reviewed by more than one pathologist), visual inspection and cervicography. Any positive screening test led to colposcopic referral and biopsy and/or excisional treatment of CIN2 or worse. We retrospectively tested stored specimens with an early HPV test (hybrid capture tube test) and for >40 HPV genotypes using a research PCR assay. We followed women typically 5-7 years and some up to 11 years. Nonetheless, 16 cases of invasive cervical cancer were diagnosed during follow-up. Six cancer cases were failures at enrollment to detect abnormalities by cytology screening; 3 of the 6 were also negative at enrollment by sensitive HPV DNA testing. Seven cancers represent failures of colposcopy to diagnose cancer or a precancerous lesion in screen-positive women. Finally, 3 cases arose despite attempted excisional treatment of precancerous lesions. Based on this evidence, we suggest that no current secondary cervical cancer prevention technologies applied once in a previously under-screened population is likely to be 100% efficacious in preventing incident diagnoses of invasive cervical cancer.

[Human papillomavirus and cervical neoplasia]. / Papilomavírus humano e neoplasia cervical.

Human papillomavirus (HPV) has been established as an important etiological factor for the development of cervical cancer. This DNA virus primarily infects the epithelium and can induce benign and malignant lesions of the mucous membranes and skin. Some HPVs are considered high risk due to their role in malignant progression of cervical tumors. Genital HPV infections are common and usually transient among young sexually active women. Only a small fraction of infected women develop cervical cancer, implying the involvement of environmental and genetic cofactors in cervical carcinogenesis. Classification, virology, pathology, natural history, epidemiological features of genital HPV infection, and future prospects for cervical cancer prevention with HPV vaccines will be reviewed here.

Papilomavírus humano e neoplasia cervical: [revisão] / Human papillomavirus and cervical neoplasia: [revision]

Human papillomavirus (HPV) has been established as an important etiological factor for the development of cervical cancer. This DNA virus primarily infects the epithelium and can induce benign and malignant lesions of the mucous membranes and skin. Some HPVs are considered high risk due to their role in malignant progression of cervical tumors. Genital HPV infections are common and usually transient among young sexually active women. Only a small fraction of infected women develop cervical cancer, implying the involvement of environmental and genetic cofactors in cervical carcinogenesis. Classification, virology, pathology, natural history, epidemiological features of genital HPV infection, and future prospects for cervical cancer prevention with HPV vaccines will be reviewed here.

O papilomavírus humano (HPV) é um fator etiológico bem estabelecido para o câncer cervical. Esse vírus de DNA infecta primariamente o epitélio e pode induzir lesões benignas ou malignas na pele e na mucosa. Alguns HPVs são considerados de alto risco, responsáveis pela progressão das lesões precursoras até câncer cervical. A infecção genital pelo HPV é comum em mulheres jovens e geralmente é transitória. Uma pequena proporção de mulheres infectadas desenvolve câncer cervical, implicando o envolvimento de fatores ambientais e fatores genéticos na carcinogênese. Essa revisão aborda a estrutura viral, classificação e patologia do HPV, história natural e fatores de risco para neoplasia cervical e perspectivas futuras com a vacina anti-HPV.

Atrofia cerebelosa por el virus JC en un paciente con SIDA / Cerebellar atrophy by the JC virus in a patient with AIDS

The progressive multifocal leukoencephalopathy (PML) is a demyelinating CNS disease, characterized by lysis of injected oligodendrocytes by JC virus (JCV). Immunodeficiency is a predisposing factor for acquiring the disease and at least 5 percent of AIDS patients may develop PML. Among patients infected with HIV has also been described the lysis of the granullar cells of the cerebellum and cerebellar atrophy, attributed to a variant of the JCV. We present 37 years old HIV infected men, with postural dizziness, followed by gait disturbances, and a cerebellar syndrome, scanned speech, hyperreflexia, pendular reflexes, Babinski sign and mild cognitive impairment were present. Brain MRI showed hyperintense areas of the white matter in the cerebral hemispheres, thalamus and brainstem, associated with incipient atrophy of the cerebellum. The CSF was normal except for the PCR positive for the JCV. The patient received antiretroviral therapy. A second MRI, eight months later, showed a slightly increase in lesions of the cerebral hemispheres, and the left cerebellar hemisphere, but had developed a marked cerebellar atrophy. After two years, the patient remained with a serious cerebellar syndrome. That in association with the slow course of the disease and the particular cerebellar lesions, are suggestive of a mixed JCV infection of both, the typical and mutant type, in this patient. This is the first case of cerebellar atrophy by the JCV reported in the Chilean literature.

La leucoencefalopatía multifocal progresiva es un proceso desmielinizante del SNC, que se caracteriza por la lisis de los oligodendrocitos infectados por el virus JC. La inmunodeficiencia es un factor predisponente para adquirir la enfermedad y al menos el 5 por ciento de los pacientes con SIDA pueden desarrollar una LMP. Entre pacientes infectados con VIH también se ha descrito una lisis de las células granulosas del cerebelo y atrofia cerebelosa, atribuida a una variante del virus JC. Se presenta un hombre de 37 años portador de VIH, que consulta por vértigos posturales, seguidos de alteraciones de la marcha y un síndrome cerebeloso, palabra escandida, hiperreflexia, reflejos pendulares, Babinski y un leve deterioro cognitivo. La RM cerebral mostró áreas de hiperintensidad en T2 de la substancia blanca en los hemisferios cerebrales, en los tálamos y en estructuras bulbo-protuberanciales, asociadas a una atrofia incipiente del cerebelo. El LCR era normal, salvo la PCR positiva para el VJC. El paciente estaba con terapia antiretroviral que se mantuvo. Una segunda RM, ocho meses después, mostró leve aumento de las lesiones de los hemisferios cerebrales, de la protuberancia y del hemisferio cerebeloso izquierdo, pero se había incrementado la atrofia de la corteza cerebelosa. Después de dos años, el paciente ha mantenido el síndrome cerebeloso, que unido a la detención clínica de la enfermedad y a la atrofia del cerebelo, sugieren que este paciente pudiera tener una doble infección por VJC tanto de la variedad típica como de la mutante. Este sería el primer caso de atrofia cerebelosa por el VJC pesquisado en Chile.

Could other viruses cause pediatric posttransplant lymphoproliferative disorder?

INTRODUCTION: Posttransplant lymphoproliferative disorder (PTLD) constitutes a heterogeneous group of diseases. We summarize the experience of our hospital, one of Spain's largest series of renal (294), liver (47) and allogeneic stem cell transplants (67), where four cases of PTLD have developed related to complex viral infections. METHODS: Case 1 was a 24-month-old boy diagnosed with acute lymphoblastic leukemia who underwent allogeneic stem-cell transplantation (SCT). He was seropositive for Epstein-Barr virus (EBV) and developed an aggressive Bcell non-Hodgkin's lymphoma (B-NHL) related to EBV reactivation and human herpesvirus 6 (HHV-6) infection. Cases 2, 3, and 4 developed after kidney transplantation and were all EBV seronegative. Case 2 had associated cytomegalovirus (CMV) and EBV infection. Cases 3 and 4 only revealed EBV viral load. Cases 1, 3, and 4 progressed rapidly, with fatal outcome. Global incidence of PTLD in our series is 1.1%. CONCLUSION: PTLD is a rare but life-threatening condition. Although EBV plays a clear role in its pathogenesis, other associated viral infections could trigger this situation. Current therapies include rituximab, decreasing immunosuppressive drugs. and conventional chemotherapy.

Rapid clearance of human papillomavirus and implications for clinical focus on persistent infections.

Health professionals and the public need to understand the natural history of human papillomavirus (HPV) infections of the cervix to best use the information provided by new molecular screening tests. We investigated outcomes of 800 carcinogenic HPV infections detected in 599 women at enrollment into a population-based cohort (Guanacaste, Costa Rica). For individual infections, we calculated cumulative proportions of three outcomes (viral clearance, persistence without cervical intraepithelial neoplasia grade 2 or worse [CIN2+], or persistence with new diagnosis of CIN2+) at successive 6-month time points for the first 30 months of follow-up. Cervical specimens were tested for carcinogenic HPV genotypes using an L1 degenerate-primer polymerase chain reaction method. Infections typically cleared rapidly, with 67% (95% confidence interval [CI] = 63% to 70%) clearing by 12 months. However, among infections that persisted at least 12 months, the risk of CIN2+ diagnosis by 30 months was 21% (95% CI = 15% to 28%). The risk of CIN2+ diagnosis was highest among women younger than 30 years with HPV-16 infections that persisted for at least 12 months (53%; 95% CI = 29% to 76%). These findings suggest that the medical community should emphasize persistence of cervical HPV infection, not single-time detection of HPV, in management strategies and health messages.