Synergistic Effects of NDRG2 Overexpression and Radiotherapy on Cell Death of Human Prostate LNCaP Cells.

BACKGROUND: Radiation therapy is among the most conventional cancer therapeutic modalities with effective local tumor control. However, due to the development of radio-resistance, tumor recurrence and metastasis often occur following radiation therapy. In recent years, combination of radiotherapy and gene therapy has been suggested to overcome this problem. The aim of the current study was to explore the potential synergistic effects of N-Myc Downstream-Regulated Gene 2 (NDRG2) overexpression, a newly identified candidate tumor suppressor gene, with radiotherapy against proliferation of prostate LNCaP cell line. MATERIALS AND METHODS: In this study, LNCaP cells were exposed to X-ray radiation in the presence or absence of NDRG2 overexpression using plasmid PSES- pAdenoVator-PSA-NDRG2-IRES-GFP. The effects of NDRG2 overexpression, X-ray radiation or combination of both on the cell proliferation and apoptosis of LNCaP cells were then analyzed using MTT assay and flow cytometery, respectively. RESULTS: Results of MTT assay showed that NDRG2 overexpression and X-ray radiation had a synergistic effect against proliferation of LNCaP cells. Moreover, NDRG2 overexpression increased apoptotic effect of X-ray radiation in LNCaP cells synergistically. CONCLUSION: Our findings suggested that NDRG2 overexpression in combination with radiotherapy may be an effective therapeutic option against prostate cancer.

Detection of t(9;22) b2a2 fusion transcript by flow cytometry.

INTRODUCTION: We assessed the feasibility of flow cytometry-fluorescent in situ hybridization technique in the detection of translocated mRNA in the cytoplasm of human peripheral blood nucleated cells. It is assumed that this assay can be applied as a diagnostic method in the detection of chromosomal translocation which commonly occurs in hematologic malignancies. METHODS: KCL-22 cell line and white blood cells from 21 CML patients were recruited in the study. Cells were isolated and fixed. After permeabilization, cells were resuspended in hybridization buffer and probes were added to the mixture. Subsequently, cells were washed and analyzed on the flow cytometer instrument. The flow cytometry results were compared with qRT-PCR and fluorescent microscope outcomes. RESULTS: Using the current principle, 97 ± 2.1% of the KCL-22 cells were labeled with b2a2 mRNA-specific probes. In addition, seven patients were recognized positive for t(9;22) b2a2. The percentage of cells containing abovementioned translocation in these patients was varied from 3.26% to 97.8%. There was no false-positive result in negative controls (K562 with BCR-ABL1 b3a2, NB4, and Jurkat cell lines) along with blood samples of normal controls. All the results obtained by flow-FISH were confirmed by qRT-PCR and fluorescent microscope. CONCLUSION: This strategy benefits from appropriate specificity, sensitivity, rapidity, and ability in the determination of malignant cell percentage. Therefore, it can improve traditional time-consuming and labor-intensive FISH method.

Effects of Hesperidin as a Radio-protector on Apoptosis in Rat Peripheral Blood Lymphocytes after Gamma Radiation.

INTRODUCTION: Hesperidin (HES), as the most abundant flavonoid existing in the citrus, is widely used by human daily. The radio-protective effects of Hesperidin have been confirmed in various measurement systems. This study aimed to evaluate the effects of Hesperidin on the changes in the apoptosis level and expression of apoptotic genes target (bax, bcl-2 and ration of bax/bcl-2) in the peripheral blood lymphocytes of male rats after gamma radiation. MATERIALS AND METHODS: 64 male rats were divided into eight groups: Control, HES (100 mg/kg b.w, orally, 7 days), whole body irradiation with 2 and 8Gy, pre-administrated with 50 and 100 mg/kg body weight of Hesperidin for 7 days before irradiation with 2 and 8 Gy. 24 hours after radiation, apoptotic lymphocytes were evaluated using PE Annexin V Apoptosis detection I kit and the levels of mRNA for bax and bcl-2 were evaluated by real time reverse transcription polymerase chain reaction. RESULTS: A significant reduction in apoptosis of the lymphocytes was demonstrated in group animals receiving 8 Gy compared to the group which received 2 Gy irradiation (p<0.0001). However, apoptosis significantly increased in group of rats who received Hesp before irradiation (p<0.05). The increase of apoptosis by Hesperidin administration can be attributed to the decreased expression of bax and significantly reduced expression of bcl-2 and finally increasing the ration of bax/bcl-2. CONCLUSION: The results suggest that administration of 50 and 100 mg/kg of Hesperidin induces apoptotic effects by changing expression level of bax, bcl-2 and also the ratio of bax/bcl2.

Construction of bacterial ghosts for transfer and expression of a chimeric hepatitis C virus gene in macrophages.

The bacterial ghost (BG) production is a field of biotechnology for applications in vaccine and drug delivery. We assessed the capacity of BG for delivery of a recombinant gene encoded for both cell mediated and antibody dependent epitopes of hepatitis C virus (HCV) into murine macrophages. Escherichia coli (E. coli) cells were transformed with the lysis plasmid (pHH43). To produce chimeric gene, NS3 (non-structural protein 3) and core regions of HCV genome were fused together by splicing by overlap extension (SOEing) PCR and were cloned into plasmid pEGFP-C1. Bacterial ghosts were loaded with recombinant pEGFP-C1 and then were transferred to murine macrophages (RAW 264.7). To investigate plasmid transfection and chimeric mRNA transcription, fluorescent microscopy and RT-PCR were used. In vitro studies indicated that bacterial ghosts loaded with pEGFP-C1 plasmid were efficiently taken up by murine macrophages and indicated a high transfection rate (62%), as shown by fluorescent microscopy. RT-PCR from extracted intracellular mRNAs for chimeric Core-NS3 gene showed a specific 607 bp fragment of the gene. The sequence analysis of purified PCR products demonstrated the expected unique mRNA sequence. We constructed a chimeric HCV gene containing both cell mediated and antibody dependent epitopes with a significant expression in murine macrophages delivered by bacterial ghost.

The molecular prevalence of viral infections in transplant candidates with bone marrow suppression, shiraz, southern iran, 2010.

BACKGROUND: Transient bone marrow suppression, characterized by acute inability of the bone marrow to produce circulating blood cells, may strongly relate to the pathogenesis of some viral infections. OBJECTIVE: To study the prevalence of some DNA and RNA viruses in patients with transient bone marrow suppression. METHODS: EDTA-treated blood samples were collected from 27 patients with clinically- and laboratory-confirmed transient bone marrow suppression. The genomic DNA of hepatitis B virus, adenovirus, polyomavirus BK, and parvovirus B19, and genomic RNA of hepatitis C and G viruses were extracted and amplified by sensitive and specific in-house simple and nested PCR and RT-PCR protocols, respectively. The risk factors that might be related to the studied viral infections were analyzed. RESULTS: Hepatitis B virus infection was diagnosed in 9 (33%) of 27 patients; adenovirus infection in 2 (7%); and parvovirus B19 infection in 7 (26%) of 27 patients. The genomic DNA of polyomovirus BK was not detected in any patients. Both hepatitis C and G viruses were found in 3 (11%) of 27 patients. CONCLUSION: Diagnosis of the high prevalence of hepatitis B virus, and parvovirus B19 in patients with transient bone marrow suppression, reflects the importance of these viral infections in introducing bone marrow suppression. This hypothesis should be confirmed in further studies.

Incidence of human herpes virus-6 and human cytomegalovirus infections in donated bone marrow and umbilical cord blood hematopoietic stem cells.

This study examined the incidence of human herpes virus-6 (HHV-6) and human cytomegalovirus (HCMV) infections that are potentially transmitted to haematopoietic stem cells (HSC) transplant recipients via bone marrow (BM) or umbilical cord blood (UCB). Bone marrow progenitor cells were collected from 30 allogenic BM donors. UCB HSC were collected from 34 subjects. The extracted DNA was then processed using nested polymerase chain reaction (nPCR) technique. HCMV and HHV-6 serological status were determined by enzyme immunoassay (EIA). Nested PCR identified HCMV in 22 (73%) of 30 samples of BM progenitor cells but in only eight (23.5%) of 34 samples of UBC HSC ( P = 0.001). HHV-6 DNA was detected in 11 (36.6%) of 30 BM progenitor cells and in only one (2.9%) of 34 UBC cells ( P = 0.002). Both HHV-6 and HCMV infections were determined in nine (26.5%) of 34 bone marrow samples. The results indicate that, the risk of HCMV and HHV-6 via BM progenitor cells is higher than transmission by UCB cells ( P= 0.04).

Anti-HBc & HBV-DNA detection in blood donors negative for hepatitis B virus surface antigen in reducing risk of transfusion associated HBV infection.

BACKGROUND & OBJECTIVE: Though sensitive screening assays for detection of hepatitis B virus surface antigen (HBsAg) are available, occasional cases of post-transfusion hepatitis B virus infection (PTH) still occur. The present study was undertaken to assess the prevalence of anti-hepatitis B core (anti-HBc) positivity and presence of HBV-DNA in serum sample of healthy blood donors negative for both HBsAg and anti-HCV antibody in Shiraz, Iran. Since anti-HBc detection is not mandatory in Iran, we evaluated whether anti-HBc detection could be adopted as a screening assay for safety of donated blood. METHODS: Two thousands serum samples negative for both HBsAg and anti-HCV collected from healthy blood donors were tested for the presence of anti HBc antibody. All samples positive for anti-HBc antibody were then investigated for determination of anti-HBc titre, anti-HBs titre, HbeAg and anti-HBe antibody by enzyme immunoassay (EIA). Every sample that tested negative for HBsAg but positive for anti-HBc alone or in combination with other serological markers was also examined for the presence of HBV-DNA by polymerase chain reaction (PCR). RESULTS: Of the 2000 samples tested, 131 (6.55%) blood samples were found to be positive for anti- HBc. HBV DNA was detected among 16 of 131(12.2%) anti-HBc positive specimens. Further, there was an association between the titration of anti-HBc antibody and the intensity of expected PCR product band. The liver function test results were all in normal range except in 4 of 16 HBV-DNA positive subjects. The mean levels of alanine aminotransferase (ALT) and aspartate aminotransferase (AST) in HBV-PCR positive subjects were 14 IU/l and 23.7 IU/l respectively. INTERPRETATION & CONCLUSION: Anti-HBc antibody should be tested routinely on blood donors volunteers and if the sample found positive regardless of anti-HBs titre, the blood should be discarded. Further testing for HBV-DNA would be appropriate to follow up the donor for HBV infection.

Outcome of hepatitis B and C virus infection on graft function after renal transplantation.

INTRODUCTION: Chronic liver disease resulting from hepatitis B virus (HBV) and hepatitis C virus (HCV) infections is still a major concern in kidney recipients. It is unclear whether HCV antibody status and markers of HBV infection are associated with renal dysfunction. Thus, we designed a study to investigate the incidence of HBV and HCV infection after renal transplantation and whether these infections alter graft function. METHODS: Fifty-eight patients who underwent renal transplantation participated in the study. Serum creatinine and aminotransferase levels were measured with standard automated analyzers. Anti-HCV antibodies were detected with an enzyme immunoassay, and a reverse transcriptase-polymerase chain reaction (RT-PCR) technique was used to test for HCV-RNA. Serological markers for HBV (HBsAg and anti-HBc antibody) were detected by enzyme immunoassay. All samples from patients who were seropositive for HBsAg or anti-HBc antibody were PCR-tested for HBV-DNA. A serum sample collected from living donors was tested for anti-HCV antibodies and serological markers for HBV. Serum creatinine and aminotransferase levels were also measured in living donors. RESULTS: Anti-HCV was not detected in serum samples of any cases before transplantation. However, 10 (17.2%) tested positive after transplantation. HCV-RNA was detected in 2 of the 10 patients (3.4% of all patients). None of the pretransplantation serum samples tested positive for HBsAg. However, anti-HBc antibody was identified in 8 (13.8%) of the 58 patients.. No HBV DNA was detected in serum samples of the patients with anti-HBc or HBsAg-positive. HBsAg was only detected in 1 (1.7%) recipient after transplantation. None of the 58 patients showed clinical signs or symptoms of renal dysfunction during the study period. CONCLUSION: Our data suggest that, neither HBV nor HCV infection appears to cause or contribute to renal dysfunction in the early period (1 year) after renal transplantation. Nevertheless, a long-term consequence of chronic HBV or HCV liver disease or graft loss is not impossible in renal transplant recipients.

Risk of viral transmission via bone marrow progenitor cells versus umbilical cord blood hematopoietic stem cells in bone marrow transplantation.

Hematopoietic stem cell transplantation (HSCT) is the treatment of choice for children and certain adults with malignant and nonmalignant hematologic disease. Since viral infections are the major problem, this study examined those that might potentially be transmitted to HSCT recipients via bone marrow (BM) versus umbilical cord blood (UCB). BM progenitor cells, peripheral blood leukocytes, and plasma samples were collected from 30 allogenic BM donors. Umbilical cord blood hematopoietic stem cells and plasma samples were also collected from 34 UCB donors. Viral DNA extracted and purified from collected specimens was processed using nested polymerase chain reactions (PCR) to detect human parvovirus B19 (HPV B19), human herpesvirus-6 (HHV-6), varicella-zoster virus (VZV), human cytomegalovirus (HCMV), and Epstein-Barr virus (EBV). The prevalences of HCMV DNA in collected BM progenitor cells versus UCB hematopoietic stem cells were 73% versus 23%, respectively. Conversely, HHV-6 DNA was not detected in any collected specimen by simple PCR. Distribution of the other investigated virus DNAs except EBV DNA was similar in specimens collected from both groups. EBV DNA was not determined in UCB hematopoietic stem cells. The results indicate that the risk of viral transmission to BM transplant recipients via UCB hematopoietic stem cells is less than that with BM progenitor cells.

Improvement in isolation of human peripheral blood leukocyte subpopulations: application in diagnosing human cytomegalovirus infection in bone marrow transplant patients.

OBJECTIVES: High-yield isolation and purification of human leukocyte subpopulations from whole blood is fundamental to many biological and medical applications including qualitative and quantitative PCR-based techniques of determining human cytomegalovirus infection. Several procedures have been reported to purify morphologically and functionally intact human leukocyte subpopulations for diagnostic proposes. Here, we report and evaluate a technique for high-yield purification of intact and viable human leukocyte subpopulations based on modification of a previous methodology. MATERIALS AND METHODS: One hundred peripheral blood samples were collected from bone marrow transplant recipients (n = 60), bone marrow donors (n = 20), and healthy blood donors (n = 20). The samples were tested in parallel using 4 different leukocyte separation methods. The methods were evaluated based on the concentration, purity, and viability of the isolated leukocyte subpopulations. RESULTS: When compared with standard methods, our methods produced 99% purity for both polymorphonuclear or mononuclear leukocytes. The corresponding viability for the methods was determined to be 98%. No erythrocyte contamination was demonstrated. However, the maximum concentration for polymorphonuclear or mononuclear leukocytes obtained by standard methods was 70%. The corresponding viability for all the methods was determined to be 98%. CONCLUSIONS: Our results indicate that in patients with decreased whole blood leukocyte numbers, using either a modified Ficoll NH(4)Cl or a modified dextran method would be valuable for simultaneous separation of polymorphonuclear and mononuclear leukocytes with high purity, viability, and concentration.

Comparative analysis of a double primer PCR assay with plasma, leukocytes and antigenemia for diagnosis of active human cytomegalovirus infection in bone marrow transplant patients.

The aim of the study was to determine the prognostic value of a double primer PCR assay to detect human cytomegalovirus (HCMV) infection or disease in bone marrow transplant (BMT) recipients. A total of 209 blood samples including peripheral blood mononuclear cells (PBMN), polymorphonuclear (PMN) leukocytes and plasma from 26 BMT recipients were tested by PCR assay. To discriminate between latent and active HCMV infection, 177 blood samples were also tested by a quantitative antigenemia assay. HCMV serology status of donors and recipients was determined before transplantation by an enzyme immunosorbent assay method. Using the double primer PCR assay, the number of positive samples increased by an average of 11.6%. Symptomatic active HCMV infection was diagnosed in 14 (53.8%) out of 26 BMT patients. There was a good association between double primer PCR assay of PMN leukocytes and antigenemia assays for detection of active HCMV infection in all patients. Detection of HCMV DNA in PMN leukocytes of BMT patients by double primer PCR assay can be an alternative method for antigenemia assay. However, quantitative PCR methods will be necessary for monitoring antiviral treatment.

Detection of BK virus and JC virus DNA in urine samples from immunocompromised (HIV-infected) and immunocompetent (HIV-non-infected) patients using polymerase chain reaction and microplate hybridisation.

BACKGROUND: The majority of the human population is infected with two human polyomaviruses BK virus (BKV) and JC virus (JCV) during childhood. After initial infection both viruses persist within renal system. Reactivation of both viruses may be linked with immunodeficiency or immunosuppressive therapy. OBJECTIVE: To evaluate the relationship between immunodeficiency and viruria, prevalence of BK and JC viruria over time was investigated in a cohort of HIV seropositive individuals at different stages of disease. The excretion in this group was compared with virus excretion in their HIV seronegative partners and in an unselected cohort of patients attending a Genito-Urinary Medicine (GUM) clinic. STUDY DESIGN: The excretion of BKV and JCV DNA in multiple urine samples from HIV-infected patients at different stages of disease and their HIV-negative partners, and in single samples from a cohort of patients at a GUM clinic was investigated. A microplate hybridisation method was developed to increase both the sensitivity and specificity of detection of the PCR product. The method was also applied to estimate the DNA copy numbers of BKV and JCV in urine samples. RESULTS: Within the HIV group, the level of immunosuppression (CD4+ category) was not associated with JCV viruria. By contrast, there was a modest correlation between immunodeficiency as indicated by a decline in CD4+ count and BKV viruria. Shedding of both BKV and JCV DNA together in urine samples of HIV-infected patients was much higher than in control groups (P = 0.02), indicating that HIV infection may associate with polyomavirus reactivation. The incidence of flu-like syndrome was much higher in HIV-infected asymptomatic individuals than acquired immunodeficiency syndrome (AIDS)-related complex (ARC)/AIDS patients. In general, the concentration of BKV DNA viruria (DNA copy number) was dependent to CD4+ counts (P = 0.008) while concentration of JCV DNA was independent to CD4+ cell count (P = 0.54). The prevalence of BKV and JCV DNA in patients who were infected with C. trachomatis was 9/50 (18%) and 11/50 (22%), respectively. BKV and JCV DNA was detected in 3/19 (15%) and 2/19 (10%) of patients who were infected with N. gonorrhoea. Results suggested that persons infected with C. trachomatis were more likely to show BKV and JCV viruria. CONCLUSION: These results confirm that shedding of BK and JC viruses in urine is not exclusively found in immunosupression, it may also occur in healthy individuals. The frequency of virus excretion is however, apparently increased in HIV-infected patients, although no firm statistical difference could be established. One of the interesting aspects of these findings was the relatively high incidence of BKV and JCV viruria in both control groups, i.e. HIV-negative partners of HIV-infected patients and patients attending a GUM clinic.

Qualitative detection of human cytomegalovirus DNA in the plasma of bone marrow transplant recipients: value as a predictor of disease progression.

OBJECTIVE: The aim of this prospective study was to determine whether human cytomegalovirus (HCMV)-DNA detected by polymerase chain reaction (PCR) analysis in the plasma of bone marrow transplant (BMT) patients is a predictor of HCMV disease progression. METHODS: Plasma samples were collected from 15 patients who received allogenic BMTs. Each individual was sampled 1 week before and then weekly for 17 weeks after transplantation. The 270 plasma specimens were processed with a PCR method for detecting HCMV-DNA. Patients were also physically examined for signs or symptoms of HCMV-related disease. RESULTS: Eight (53.5%) of the 15 patients tested positive for HCMV-DNA. Two (25%) of these 8 individuals also had positive PCR findings before transplantation. Six (75%) of the 8 HCMV-DNA-positive patients had positive plasma-PCR results a week before clinical symptoms developed. The other 2 (25%) remained asymptomatic throughout their hospital stay. All 6 symptomatic cases were treated with ganciclovir, and 4 converted to negative plasma-PCR status at a median of 21 days. There was a significant correlation between PCR-detection of HCMVDNA in plasma and presence of HCMV-related symptoms (P < 0.01). CONCLUSION: Qualitative plasma-PCR analysis before and after bone marrow transplantation is a valuable way to screen for HCMV infection in BMT patients. Plasma-PCR monitoring of HCMV activity in this patient group might make it possible to administer an antiviral drug and thus reduce mortality. However, quantitative PCR is still considered the best way to accurately identify active HCMV infection and monitor treatment.

Clinical signs as a guide for performing HSV-PCR in correct diagnosis of herpes simplex virus encephalitis.

BACKGROUND: Clinical criteria (symptoms) are not reliable enough to differentiate between different causes of encephalitis. The clinical presentation of herpes simplex virus encephalitis (HSVE) is not classically constant and in such a patient, therefore, it is vital to make early diagnosis. AIMS: To investigate satisfactory and crucial clinical signs as guide to perform HSV-PCR in a rapid diagnosis of herpes simplex virus encephalitis. MATERIAL AND METHODS: A total of 156 CSF specimens from 70 patients with clinically suspected HSVE or meningoencephalitis were tested. The criteria for cases suspected of HSVE were fever >380C, altered mental status and other critical manifestations. CSF features, irregularity in brain CT scan and MRI findings were also assessed. All the specimens were collected before and after Acyclovir treatment. Polymerase chain reaction was performed using primers, which amplified DNA sequences for both HSV-1 and HSV-2. STATISTICAL ANALYSIS: To analyze data, two-tailed Fisher's exact test and the X2-test with Yates' correction were used as appropriate. The odds ratio was used to express the strength of association between the clinical factors and the PCR results. RESULTS: HSV-DNA was detected in 18% of the specimens, belonging to 25.7% of the patients. Results indicate that the majority of the clinical symptoms are not specific to definitive clinical diagnosis of HSVE, except alteration in the level of consciousness--odds ratio [0.27 (0.07-0.96) (P=0.033)]; and lateralization sign--odds ratio [4.7 (0.98-22.6) (P=0.023)]. However, laboratory data, including total white blood cell count, especially the number of lymphocytes, and MRI findings could be suggested for HSV-PCR examination. CONCLUSION: At the first admission, a preliminary finding of at least two important clinical features mentioned above along with the pattern of CSF cell and differential counts could be sufficient to perform HSV-PCR which could ultimately result in a rapid and correct diagnosis of herpes simplex encephalitis.

BK virus DNA in CSF of immunocompetent and immunocompromised patients.

AIM: To investigate the possible aetiological role of BK and JC viruses in immunocompetent and immunocompromised children with suspected encephalitis and meningoencephalitis. METHODS: The polymerase chain reaction and microplate hybridisation method was employed for the detection of polyomavirus DNA in 266 CSF specimens collected from immunocompetent and immunocompromised patients. RESULTS: BK virus DNA was detected in three (2.1%) CSF samples taken from patients aged 2-5 years; two were patients with acute lymphocytic leukaemia without overt neurological symptoms, the other was a patient with suspected encephalitis. BK virus DNA was also detected in two (1.6%) CSF samples taken from older children in the age range 10-16 years; both children had suspected encephalitis. JC virus DNA was not found in any CSF sample from either age group. CONCLUSIONS: Detection of BK virus in the CSF of immunocompromised and immunocompetent patients with suspected neurological disease suggests that this virus may have had a pathogenic role in the aetiology of this condition.

BKV-DNA and JCV-DNA in CSF of patients with suspected meningitis or encephalitis.

BACKGROUND: Few studies have looked for the polyoma viruses JC or BK virus in the central nervous system (CNS) of patients without neurological symptoms or with neurological symptoms other than progressive multifocal leukoencephalopathy (PML). PCR-microplate hybridization method was employed for the detection of BKV-DNA or JCV-DNA in cerebrospinal fluid (CSF) specimens from patients with suspected meningitis or encephalitis. MATERIALS AND METHODS: A total of 181 CSF specimens from 151 patients with suspected meningitis or encephalitis was examined for BKV or JCV using PCR-microplate hybridization method. None of the patients had (clinically diagnosed) PML. A control group consisting of 20 CSF specimens from normal subject was also included. RESULTS: BKV DNA was found in five out of 131 (3.8%) and JCV DNA in two out of 131 (1.5%) of the patients with suspected meningitis or encephalitis by PCR ELISA. BKV or JCV DNA was not detected in CSF samples of any of 19 HIV positive patients. BKV and JCV DNAs were detected respectively in two CSF samples in which Mycobacterium tuberculosis (TB) PCR was also positive. Another patient who was positive for JCV PCR died with a diagnosis of cerebral lymphoma. Among the BK virus infected patients there was a patient with a previous history of hemolytic uremia and acute renal failure. Neither BKV nor JCV DNA was found in any of the 20 CSF samples from normal patients undergoing lumbar puncture for myelography as a part of an investigation of lower back pain. CONCLUSION: These results suggest that BK virus may be associated with neurological diseases either in immunocompetent or immunocompromised patients. Detection of BKV and JCV DNA in the CSF of the patients suspected to have either meningitis or encephalitis suggests that these viruses may have an etiological role. Thus, diagnostic tests for BK and JC viruses should be included in the investigative program for meningitis or encephalitis patients.