The AABB (formerly the American Association of Blood Banks) has issued a revised fact sheet on XMRV. The pdf link to the fact sheet is here: http://www.aabb.org/documents/About_Blood/EID/xmrvfactsheet.pdf
Bottom line looks to me like they are not banning CFS donors, except for those who are known XMRV positive. Someone with more functioning brain cells than me will have to parse all the differences out. I tried to catch all the places things were changed or reworded from the January AABB statement. Hopefully I got them all. Here is Before and After of each change:
Bottom line looks to me like they are not banning CFS donors, except for those who are known XMRV positive. Someone with more functioning brain cells than me will have to parse all the differences out. I tried to catch all the places things were changed or reworded from the January AABB statement. Hopefully I got them all. Here is Before and After of each change:
Before, under Disease Name: Evidence of association, but not causation, has been reported for XMRV infection with the following conditions: Prostate cancer; Chronic Fatigue Syndrome (CFS)
After, under Disease Name: No confirmed disease associations
After, under Disease Name: No confirmed disease associations
Before, under Background: In 2009, a statistical association of XMRV infection with CFS was reported. Peripheral blood mononuclear cells (PBMC) from 67% of stringently defined CFS patients contained the proviral DNA of XMRV compared to 3.7% of healthy controls. These patients did not have the RNase L polymorphism mentioned above. Secondary infections in tissue culture could be established from PBMCs, B and T cells and plasma of patients. The study concluded, (T)hese findings raise the possibility that XMRV may be a contributing factor in the pathogenesis of CFS.
After, under Background: First paragraph is same as above. The section then continues:
After, under Background: First paragraph is same as above. The section then continues:
- 186 CFS patients from a UK cohort who had been described as being unwell for a median of 4 years were screened for XMRV provirus and the closely related murine leukemia virus (MLV) from whole blood preparations. Neither XMRV nor MLV sequences were detected from any of the CFS cases.
- Another UK study tested 170 CFS patients from two cohorts (one with long-term established CFS and the other with samples collected 1.5-4 years after a CFS diagnosis) and 395 controls including 157 blood donors. DNA was extracted from PBMC and tested by RT-PCR targeting two envelope regions (sensitivity of 16 copies). No XMRV sequences were identified from 142 CFS cases and 157 controls tested. However, 26 of 565 (4.6%) samples had XMRV neutralizing antibody activity but only one of the 26 was from a CFS patient. Four samples were XMRV specific but most of the remaining antibody reactivity was due to cross-reactivity with other viruses. The authors note that XMRV infection may occur in the general population, although with currently uncertain outcomes.
- In a Dutch cohort, PBMC cryopreserved in 1991-1992 from 32 CFS patients and 43 healthy controls tested by RT-PCR targeting the integrase gene and/or a nested PCR assay targeting the gag gene and having a sensitivity of 10 XMRV sequence copies per 105 PBMC failed to detect XMRV sequences in any sample.
- Reasons for the discordant findings are not clear but may include differences in the cohorts studied or selection of patients from cohorts for testing, variable assay procedures, differences in prevalence in different geographic areas, varying properties of XMRV or other factors.
Before, under Blood Phase: A perspective accompanying the original CFS study concluded (G)iven that infectious virus is present in plasma and in blood cells, blood-borne transmission is a possibility.
After, under Blood Phase: The first published XMRV-CFS study found culturable virus in plasma and PBMC.
After, under Blood Phase: The first published XMRV-CFS study found culturable virus in plasma and PBMC.
Before, under Case/Frequency in Population: In the CFS study referred to above, 3.7% of healthy controls harbored viral DNA sequences in PBMCs; however, the expression pattern of viral genes in the infected controls appeared to differ from those among the CFS population so the relevance of the observation must be explored.
After, under Case/Frequency in Population: In one CFS study, 3.7% of healthy controls harbored viral DNA sequences in PBMC; however, the expression pattern of viral genes in the infected controls appeared to differ from those among the CFS population so the relevance of the observation must be explored. Preliminary data from another study using developmental serological methods in a small sample of US blood donors found a seroprevalence of -0.1%.
The population prevalence of XMRV infection is unknown and rates may vary in different regions.
After, under Case/Frequency in Population: In one CFS study, 3.7% of healthy controls harbored viral DNA sequences in PBMC; however, the expression pattern of viral genes in the infected controls appeared to differ from those among the CFS population so the relevance of the observation must be explored. Preliminary data from another study using developmental serological methods in a small sample of US blood donors found a seroprevalence of -0.1%.
The population prevalence of XMRV infection is unknown and rates may vary in different regions.
Before, under Primary Disease Symptoms: Many prostate cancers are asymptomatic, but symptoms of urinary obstruction and metastatic spread occur with advancing disease. CFS (also called, more descriptively, myalgic encephalitis) is characterized by persistent or recurrent fatigue, diffuse musculoskeletal pain, sleep disturbances, and subjective cognitive impairment of 6 months duration or longer. Symptoms are not caused by ongoing exertion, are not relieved by rest, and result in a substantial reduction of previous levels of occupational, educational, social, or personal activities. Alterations of immune, neuroendocrine, and autonomic function may be associated with this syndrome, but none is diagnostic. There is considerable overlap between this condition, fibromyalgia, and some affective disorders.
After, under Primary Disease Symptoms: Many prostate cancers are asymptomatic, but symptoms of urinary obstruction and metastatic spread occur with advancing disease. CFS (also called, more descriptively, myalgic encephalomyelitis) is characterized by new onset, unexplained, persistent or recurrent fatigue, diffuse post-exertional malaise and/or fatigue, myalgia, sleep dysfunction, and neurological/cognitive impairment with immune, autonomic and/or neuroendocrine manifestations of 6 months duration or longer (3 months in children). Symptoms are not caused by ongoing exertion, are not relieved by rest, and result in a substantial reduction of previous levels of occupational, educational, social, or personal activities. Co-morbid conditions, such as fibromyalgia syndrome and irritable bowel syndrome may overlap with CFS. The clinical case definition includes a list of exclusionary conditions.
After, under Primary Disease Symptoms: Many prostate cancers are asymptomatic, but symptoms of urinary obstruction and metastatic spread occur with advancing disease. CFS (also called, more descriptively, myalgic encephalomyelitis) is characterized by new onset, unexplained, persistent or recurrent fatigue, diffuse post-exertional malaise and/or fatigue, myalgia, sleep dysfunction, and neurological/cognitive impairment with immune, autonomic and/or neuroendocrine manifestations of 6 months duration or longer (3 months in children). Symptoms are not caused by ongoing exertion, are not relieved by rest, and result in a substantial reduction of previous levels of occupational, educational, social, or personal activities. Co-morbid conditions, such as fibromyalgia syndrome and irritable bowel syndrome may overlap with CFS. The clinical case definition includes a list of exclusionary conditions.
Before, under Agent Specific Screening Question(s): No specific question is in use for blood donors and is not indicated because transfusion transmission has not been demonstrated.
After, under Agent Specific Screening Question(s): No specific question is in use for blood donors and is not indicated because transfusion transmission has not been demonstrated.
- No sensitive or specific question is feasible.
- The high apparent prevalence of infection reported in healthy control subjects and the high prevalence of chronic fatigue in the population are expected to make donor history screening unreliable. The rate at which potential donors carrying a criteria- based diagnosis of CFS present to donor centers is unknown, but probably low in light of the associated disability.
After, under Agent Specific Screening Question(s): No specific question is in use for blood donors and is not indicated because transfusion transmission has not been demonstrated.
- No XMRV-specific question is feasible in the absence of any established risk factors for XMRV infection and the experimental nature and limited availability of diagnostic tests.
- No sensitive or specific question is feasible for CFS.
- If the high apparent prevalence of XMRV infection reported in healthy control subjects in the original CFS study is confirmed, and given the high prevalence of chronic fatigue in the population, donor history screening would not be expected to be effective.
- The rate at which potential donors carrying a criteria- based diagnosis of CFS would present to donor centers is unknown, but probably low in light of the associated disability.
Before, under Laboratory Tests: Research assays include PCR, cell culture, flow cytometry-based immunoassay, and immunohistochemical analyses.
After, under Laboratory Tests: Research assays include RT-PCR, cell culture, flow cytometry-based immunoassay, chemiluminescent immunoassay and immunohistochemical analyses.
After, under Laboratory Tests: Research assays include RT-PCR, cell culture, flow cytometry-based immunoassay, chemiluminescent immunoassay and immunohistochemical analyses.
Before, under Currently Recommeded Donor Deferral Period:
After, under Currently Recommended Donor Deferral Period:
- No FDA Guidance or AABB Standard exists for blood donors.
- Current practice is to accept donors who are healthy at the time of donation.
- Pending the availability of further data, prudent practice would be indefinite deferral of donors who have received a diagnosis of XMRV infection.
After, under Currently Recommended Donor Deferral Period:
- No FDA Guidance or AABB Standard exists regarding XMRV infection.
- Pending the availability of further data, prudent practice would be indefinite deferral of donors who have received a diagnosis of XMRV infection.
- Current practice per FDA Guidance and AABB Standards is to accept donors who are healthy at the time of donation.
- CFS advocacy organizations and the National Cancer Institute have historically discouraged blood donation by CFS patients.
- Blood collection facilities should follow established SOPs regarding donors with cancer.
