Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0015674 (chronic fatigue syndrome)
 2,978 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Serum samples collected from patients with a wide variety of diseases from African and other countries were tested for antibodies to the human spumaretrovirus (HSRV). A spumaviral env-specific ELISA was employed as screening test. Out of 3020 human sera screened, 106 were found to be positive (3.2%). While the majority of patients' sera from Europe (1581) were negative, 26 were positive (1.6%). Sera from healthy adult blood donors (609), from patients with multiple sclerosis (48), Graves' disease (45), and chronic fatigue syndrome (41) were negative or showed a very low prevalence for spumaviral env antibodies. A higher percentage of seropositives (6.3%) were found among 1338 African patients from Tanzania, Kenya, and Gabon. Out of 1180 patients from Tanzania, 708 suffered from tumors, 75 from AIDS, and 128 had gynecological problems; 51 of the Tanzanian patients were HSRV seropositive (4.3%). A particularly high percentage of 16.6% seropositives were identified among nasopharyngeal carcinoma patients (NPC) from Kenya and Tanzania consistent with results reported 10 years ago. However, 20 nasopharyngeal carcinoma patients from Malaysia were HSRV-seronegative. In selected cases, sera from seropositive individuals were reacted with proteins from HSRV-infected cells in vitro. HSRV env- and gag-specific antibodies were specifically detected by these sera in Western blots. The results indicate spumavirus infections in human patients with various diseases at a relatively low prevalence worldwide; in African patients, however, the prevalence of spumavirus infections is markedly higher.
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PMID:Human spumavirus antibodies in sera from African patients. 131 48

Chronic fatigue syndrome (CFS) is newly-recognized disease characterized by chronic and debilitating fatigue. It has been suggested that viral infection may be involved in this syndrome from the results of clinical examination, including increased activity of 2',5'-synthetase in leukocytes of patients. The following viruses have been reported as etiologic agents of this disease. First, many studies have found elevated levels of IgG to viral capsid antigen and early antigens to Epstein-Barr virus (EBV), but low titer or absence of antibody to EBV-associated nuclear antigen. Second, the enteroviruses have also been implicated as possible causative agent of CFS, because virus could be isolated from patients. Recently it was also reported that antibodies to human T-lymphotropic virus (HTLV) and HTLV type II (HTLV-II) gag sequence were detectable in patients. Finally several reports state that human herpesvirus 6 (HHV-6) could be isolated from CFS patients in the high frequency. In conclusion, it is still early to identify the etiologic agent from these reports, and more effort is needed.
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PMID:[Chronic fatigue syndrome and virus infection: human herpesvirus 6 (HHV-6) infection]. 133 58

Within the last few years significant efforts have been made to identify objective reliable diagnostic markers from individuals with chronic fatigue syndrome (CFS). We report the absence of a previously described retroviral marker (HTLV-II gag) in a blinded study of CFS cases. Even with excellent reproducible sensitivities, this marker failed in repeated attempts to distinguish cases from controls. In addition, four other retroviruses (simian T cell leukaemia virus, human spumavirus, bovine leukaemia virus and simian retrovirus) were examined for their presence in these CFS cases and found to be absent. Our findings suggest that these agents, at least as markers, are non-distinguishing for CFS and that other factors may be confounding the resolution of an aetiology to this syndrome.
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PMID:Investigation of retroviral involvement in chronic fatigue syndrome. 838 9

Chronic fatigue syndrome (CFS) is a serious systemic illness of unknown cause. A recent study identified DNA from a xenotropic murine leukemia virus-related virus (XMRV) in peripheral blood mononuclear cells (PBMCs) from 68 of 101 patients (67%) by nested PCR, as compared with 8 of 218 (3.7%) healthy controls. However, four subsequent reports failed to detect any murine leukemia virus (MLV)-related virus gene sequences in blood of CFS patients. We examined 41 PBMC-derived DNA samples from 37 patients meeting accepted diagnostic criteria for CFS and found MLV-like virus gag gene sequences in 32 of 37 (86.5%) compared with only 3 of 44 (6.8%) healthy volunteer blood donors. No evidence of mouse DNA contamination was detected in the PCR assay system or the clinical samples. Seven of 8 gag-positive patients tested again positive in a sample obtained nearly 15 y later. In contrast to the reported findings of near-genetic identity of all XMRVs, we identified a genetically diverse group of MLV-related viruses. The gag and env sequences from CFS patients were more closely related to those of polytropic mouse endogenous retroviruses than to those of XMRVs and were even less closely related to those of ecotropic MLVs. Further studies are needed to determine whether the same strong association with MLV-related viruses is found in other groups of patients with CFS, whether these viruses play a causative role in the development of CFS, and whether they represent a threat to the blood supply.
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PMID:Detection of MLV-related virus gene sequences in blood of patients with chronic fatigue syndrome and healthy blood donors. 2220 80

In 2006, sequences described as xenotropic murine leukemia virus-related virus (XMRV) were discovered in prostate cancer patients. In October 2009, we published the first direct isolation of infectious XMRV from humans and the detection of infectious XMRV in patients with chronic fatigue syndrome. In that study, a combination of classic retroviral methods were used including: DNA polymerase chain reaction and reverse transcriptase polymerase chain reaction for gag and env, full length genomic sequencing, immunoblotting for viral protein expression in activated peripheral blood mononuclear cells, passage of infectious virus in both plasma and peripheral blood mononuclear cells to indicator cell lines, and detection of antibodies to XMRV in plasma. A combination of these methods has since allowed us to confirm infection by XMRV in 85% of the 101 patients that were originally studied. Since 2009, seven studies, predominantly using DNA polymerase chain reaction of blood products or tumor tissue, have reported failures to detect XMRV infection in patients with either prostate cancer or chronic fatigue syndrome. A review of the current literature on XMRV supports the importance of applying multiple independent techniques in order to determine the presence of this virus. Detection methods based upon the biological and molecular amplification of XMRV, which is usually present at low levels in unstimulated blood cells and plasma, are more sensitive than assays for the virus by DNA polymerase chain reaction of unstimulated peripheral blood mononuclear cells. When we examined patient blood samples that had originally tested negative by DNA polymerase chain reaction by more sensitive methods, we observed that they were infected with XMRV; thus, the DNA polymerase chain reaction tests provided false negative results. Therefore, we conclude that molecular analyses using DNA from unstimulated peripheral blood mononuclear cells or from whole blood are not yet sufficient as stand-alone assays for the identification of XMRV-infected individuals. Complementary methods are reviewed, that if rigorously followed, will likely show a more accurate snapshot of the actual distribution of XMRV infection in humans.
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PMID:Distribution of xenotropic murine leukemia virus-related virus (XMRV) infection in chronic fatigue syndrome and prostate cancer. 2084 3

A xenotropic murine leukemia virus-related virus (XMRV) has recently been reported in association with prostate cancer and chronic fatigue syndrome, with a prevalence of up to 3.7% in the healthy population. We looked for XMRV in 230 patients with human immunodeficiency virus type 1 or hepatitis C infection. XMRV was undetectable in plasma or peripheral blood mononuclear cells by polymerase chain reaction targeting XMRV gag or env. T cell responses to XMRV Gag were undetectable in peripheral blood mononuclear cells by ex vivo gamma interferon enzyme-linked immunospot assay. In our cohorts, XMRV was not enriched in patients with blood-borne or sexually transmitted infections from the United Kingdom and Western Europe.
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PMID:Failure to detect xenotropic murine leukemia virus-related virus in blood of individuals at high risk of blood-borne viral infections. 2093 81

During pilot studies to investigate the presence of viral RNA of xenotropic murine leukemia virus (MLV)-related virus (XMRV) infection in sera from chronic fatigue syndrome (CFS) patients in Japan, a positive band was frequently detected at the expected product size in negative control samples when detecting a partial gag region of XMRV using a one-step RT-PCR kit. We suspected that the kit itself might have been contaminated with small traces of endogenous MLV genome or XMRV and attempted to evaluate the quality of the kit in two independent laboratories. We purchased four one-step RT-PCR kits from Invitrogen, TaKaRa, Promega and QIAGEN in Japan. To amplify the partial gag gene of XMRV or other MLV-related viruses, primer sets (419F and 1154R, and GAG-I-F and GAG-I-R) which have been widely used in XMRV studies were employed. The nucleotide sequences of the amplicons were determined and compared with deposited sequences of a polytropic endogenous MLV (PmERV), XMRV and endogenous MLV-related viruses derived from CFS patients. We found that the enzyme mixtures of the one-step RT-PCR kit from Invitrogen were contaminated with RNA derived from PmERV. The nucleotide sequence of a partial gag region of the contaminant amplified by RT-PCR was nearly identical (99.4% identity) to a PmERV on chromosome 7 and highly similar (96.9 to 97.6%) to recently identified MLV-like viruses derived from CFS patients. We also determined the nucleotide sequence of a partial env region of the contaminant and found that it was almost identical (99.6%) to the PmERV. In the investigation of XMRV infection in patients of CFS and prostate cancer, researchers should prudently evaluate the test kits for the presence of endogenous MLV as well as XMRV genomes prior to PCR and RT-PCR tests.
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PMID:An endogenous murine leukemia viral genome contaminant in a commercial RT-PCR kit is amplified using standard primers for XMRV. 2117 78

In 2009, a newly discovered human retrovirus, xenotropic murine leukemia virus (MuLV)-related virus (XMRV), was reported by Lombardi et al. in 67% of persons from the US with chronic fatigue syndrome (CFS) by PCR detection of gag sequences. Although six subsequent studies have been negative for XMRV, CFS was defined more broadly using only the CDC or Oxford criteria and samples from the US were limited in geographic diversity, both potentially reducing the chances of identifying XMRV positive CFS cases. A seventh study recently found polytropic MuLV sequences, but not XMRV, in a high proportion of persons with CFS. Here we tested blood specimens from 45 CFS cases and 42 persons without CFS from over 20 states in the United States for both XMRV and MuLV. The CFS patients all had a minimum of 6 months of post-exertional malaise and a high degree of disability, the same key symptoms described in the Lombardi et al. study. Using highly sensitive and generic DNA and RNA PCR tests, and a new Western blot assay employing purified whole XMRV as antigen, we found no evidence of XMRV or MuLV in all 45 CFS cases and in the 42 persons without CFS. Our findings, together with previous negative reports, do not suggest an association of XMRV or MuLV in the majority of CFS cases.
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PMID:Serologic and PCR testing of persons with chronic fatigue syndrome in the United States shows no association with xenotropic or polytropic murine leukemia virus-related viruses. 2134 21

The human pathogen xenotropic murine leukaemia virus-related virus (XMRV) has been tentatively associated with prostate cancer and chronic fatigue syndrome. Unfortunately, subsequent studies failed to identify the virus in various clinical settings. To determine whether XMRV circulates in humans and the relationship with its host, we searched for the virus in 124 human immunodeficiency virus-infected patients who might have been exposed to XMRV, might be prone to infection as a result of progressive immunodeficiency, and had not yet been treated with antiretroviral drugs. Using nested PCR and single-step TaqMan real-time PCR, both designed on the XMRV gag gene, we could not find any positive samples. These findings add to the growing amount of scepticism regarding XMRV.
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PMID:Xenotropic murine leukaemia virus-related virus is not found in peripheral blood cells from treatment-naive human immunodeficiency virus-positive patients. 2167 82

We investigated the presence of XMRV in a cohort of Quebec patients with chronic fatigue syndrome (CFS). DNA was purified from activated peripheral blood mononuclear cells (PBMCs) and PCR was used to detect XMRV gag and env in 72 patients. Anti-XMRV antibodies were searched in sera of 62 patients by Western blot analysis. Attempts to detect XMRV antigens was made, using immunofluorescence with Gag anti-p30 antiserum on activated PBMC from 50 patients. Plasma viremia was measured by RT-PCR on 9 subjects. Finally, detection of infectious virus in 113 CFS subjects was made by co-culture of PHA+IL-2 activated PBMC with human LNCaP carcinoma cells, and by infecting the same susceptible cells with plasma, using a reverse transcriptase (RT) assay as a readout in both experiments. No detection of XMRV footprints nor infectious virus was detected with any of the approaches, in any of the tested individuals.
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PMID:No detectable XMRV in subjects with chronic fatigue syndrome from Quebec. 2192 93


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