Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0021051 (immunodeficiency)
 71,517 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Human parvovirus B19 (B19) has been described as a causative agent of chronic anemia in human immunodeficiency virus type-1 (HIV-1)-infected patients. We report an HIV-1 infected patient who had been receiving anti-retroviral therapy who showed sudden pancytopenia. Primary B19 infection was confirmed by the detection of plasma viremia and seroconversion. Although clearance required a prolonged period of time, the patient eventually cleared the B19 viral DNA from the plasma. More than likely, highly active anti-retroviral therapy (HAART), including a protease inhibitor, played a role in clearing the virus.
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PMID:Acute parvovirus B19 infection during anti-retroviral therapy. 1145 1

Despite the much lower actual yield than that estimated for hepatitis C virus (HCV) and human immunodeficiency virus (HIV) nucleic acid testing (NAT)-only positives in the USA and Germany, look-back procedures have revealed that no HCV transmission has occurred in Germany since the introduction of NAT. This indicates sufficient sensitivity of the pool-PCR approach. The slow ramp-up of hepatitis B virus (HBV) however, may require a different approach. It has been shown in Germany that the pooling of samples followed by virus enrichment results in a significant yield. Single donation testing for HBV would not increase the yield, because virus enrichment from mini-pool results in a similar sensitivity to that of single donation testing. Both strategies may be useful for extending future NAT to HBV screening. New candidate viruses for NAT are Parvo B19 and hepatitis A virus (HAV) because of their extreme resistance to inactivation procedures. Their low pathogenicity and epidemiologic characteristics, however, make them candidate viruses only for pooled source plasma. The main future issues of NAT will be related to the automation of pooling, extraction and amplification as a single homogeneous process. Depending on the throughput, automated single donation NAT as demonstrated by the 'Tigris' system may be an option, as far as all transfusion-relevant viruses will be included. In the near future high throughput systems will rely on pooled donor samples, most probably in conjunction with efficient enrichment procedures. For these systems, automation of the extraction and amplification process will be one of the first steps. These procedures will also limitthe costs of NAT and keep it available for use with future candidate viruses.
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PMID:Yield and future issues of nucleic acid testing. 1149 78

Nucleic acid testing (NAT) holds the promise of closing the window of infectiousness for hepatitis C virus (HCV) and the human immunodeficiency virus (HIV) in the general blood supply. Pioneering work by the source plasma industry with NAT for hepatitis A virus (HAV), hepatitis B virus (HBV), and parvovirus B19 suggests that, in the future, the risk of other viral infections may be reduced using similar technology. The European Commission decree that, by July 1999, all source plasma for fractionation should be NAT nonreactive for HCV at a sensitivity of 100 viral IU/mL, has driven the implementation of NAT in the United States. It is estimated that more than 95% of the US blood supply is currently tested by one of two investigational tests for HCV and HIV, and many institutions restrict the release of red blood cell (RBC) and plasma products prior to the release of NAT results. NAT implementation has been hampered by a lack of fully automated, low-cost technologies; the absence of Food and Drug Administration (FDA)-approved and validated clinical tests; and lagging turnaround times. Results from US investigational trials of the Procleix Transcription Mediated Amplification (TMA) HCV/HIV (Chiron Corp, Emeryville, CA) and the COBAS AmpliScreen (Roche Diagnostics, Indianapolis, IN) polymerase chain reaction (PCR) assays have begun to substantiate their value. While NAT assays will not replace serologic tests, they lay the groundwork for further reducing the already low risk of infection transmission through transfusion of blood components and their factor derivatives.
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PMID:Nucleic acid testing: update and applications. 1168 21

This review focuses on the role that human parvovirus B19 nonstructural (NS1) protein as a transactivator of the proinflammatory cytokine, interleukin-6 (IL-6), might play in triggering the multiparametric inflammatory outcomes of B19 infection. Parvovirus B19 is a ubiquitous virus, and it is often expressed during conditions of immunodepression including that induced by long-term chemotherapy, viral infection (HIV, HTLV-1), or genetic immunodeficiency disorders. Through NS1 expression, B19 may contribute to the immune dysregulation associated with these disorders, or serve as a cofactor in enhancing retroviral replication. Hence, NS1 transactivation of proinflammatory cytokine promoters such as IL-6 may be pivotal in triggering the various inflammatory and autoimmune disorders that have been linked to parvovirus B19 infections.
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PMID:Parvovirus B19 nonstructural (NS1) protein as a transactivator of interleukin-6 synthesis: common pathway in inflammatory sequelae of human parvovirus infections? 1199 89

Appropriate preconception health care improves pregnancy outcomes. When started at least one month before conception, folic acid supplements can prevent neural tube defects. Targeted genetic screening and counseling should be offered on the basis of age, ethnic background, or family history. Before conception, women should be screened for human immunodeficiency virus and syphilis infection and begin treatment to prevent the transmission of disease to the fetus. Immunizations against hepatitis B, rubella, and varicella should be completed, if needed. Women should be counseled on ways to prevent infection with toxoplasmosis, cytomegalovirus, and parvovirus B19. Environmental toxins such as cigarette smoke, alcohol, and street drugs, and chemicals such as solvents and pesticides should be avoided. In women with diabetes, it is important to optimize disease control through intensive management before pregnancy. Medications for hypertension, epilepsy, thromboembolism, depression, and anxiety should be reviewed and changed, if necessary, before the patient becomes pregnant. Counseling about exercise, obesity, nutritional deficiencies, and the overuse of vitamins A and D is beneficial. Physicians may also choose to discuss occupational and financial issues related to pregnancy and to screen patients for domestic violence.
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PMID:Preconception health care. 1261 25

The virucidal spectrum of a high concentration alcohol mixture (80% ethanol and 5% isopropanol) was determined for a broad series of lipid-enveloped (LE) and non-lipid-enveloped (NLE) viruses covering all relevant blood-borne viruses. LE viruses were represented by human immunodeficiency virus (HIV), bovine viral diarrhoea virus (BVDV), a specific model virus for hepatitis C virus (HCV), pseudorabies virus (PRV), and vaccinia virus. For the NLE viruses hepatitis A virus, canine parvovirus (a model for human parvovirus B19), and reovirus type 3 (Reo-3) were used. PRV, vaccinia, and Reo-3 served as general model viruses. The alcohol mixture was spiked with 5% (v/v) virus, mixed and tested for residual virus after 5 min treatment. Complete clearance (reduction by a factor of >10(6)) was observed for LE viruses, whereas incomplete to insignificant clearance (ranging from no reduction up to a maximum factor of 10(4)) was found for NLE viruses. In a second series of spiking experiments using the LE viruses BVDV, HIV, and PRV, complete clearance (reduction by a factor of >10(6)) was found after 20 s treatment. These data strongly suggest that treatment with a high concentration alcohol mixture has a high virucidal potential in particular for the blood-borne LE-viruses HIV, hepatitis B virus, and HCV. Such mixtures are well suited for rapid and frequent disinfection in dental practice being non-hazardous and non-toxic.
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PMID:The virucidal spectrum of a high concentration alcohol mixture. 1209 Jul 99

In the production of bone grafts intended for transplantation, basic safety measures to avoid the transmission of pathogens are selection and serological screening of donors for markers of virus infections. As an additional safety tool we investigated the effect of gamma irradiation on the sterility of human bone diaphysis transplants and evaluated its impact on the virus safety of transplants. Model viruses were included in the study to determine the dose necessary to achieve a reduction factor for the infectivity titres of at least 4 log(10) at a temperature of -30+/-5 degrees C. The following viruses were used: human immunodeficiency virus type 2 (HIV-2), hepatitis A virus (HAV), and poliovirus (PV-1), and the following model viruses: pseudorabies virus (PRV) as a model for human herpesviruses, bovine viral diarrhoea virus (BVDV) for HCV, and bovine parvovirus (BPV) for parvovirus B19. A first approach was to determine the D(10) values (kGy) for the different viruses (virus inactivation kinetics: BPV 7.3; PV-1 7.1; HIV-2 7.1; HAV 5.3; PRV 5.3; BVDV <3.0 kGy). Based on these results, inactivation of these viruses was studied in experimentally contaminated human bone transplants (femoral diaphyses). For BPV, the most resistant one of the viruses studied, a dose of approximately 34 kGy was necessary to achieve a reduction of infectivity titres of 4 log(10). We therefore recommend a dose of 34 kGy for the sterilisation of frozen bone transplants.
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PMID:Effect of gamma irradiation on human cortical bone transplants contaminated with enveloped and non-enveloped viruses. 1212 14

The development of new technologies leads to the discovery of new viruses. For each of these new infectious agents, relevance to transfusion, including transmissibility by transfusion, pathogenicity, prevalence in blood donors, persistence and the availability of screening assays needs to be assessed. Since 1995, one virus and a new family of viruses have been identified. GB virus-C/hepatitis G virus (GBV-C/HGV), a flavi virus with some homology with and epidemiological features of HCV, is not related to post-transfusion hepatitis but seems to positively interfere with human immunodeficiency virus replication. Human circoviruses include TT virus (TTV) and SEN-V. Both are highly variable, constituting a large family of distantly related viruses. They appear ubiquitous, infecting humans very early in life and are largely persistent. No clinical symptoms or pathogenicity is associated with TTV, but SEN-V might be associated with some non-A-E post-transfusion hepatitis. Parvovirus B19 has been known for many years, but its transmission to recipients of plasma derivatives despite viral inactivation raised the issue of screening plasma pools by nucleic acid testing. Most fractionators quantify B19 DNA in plasma pools to ensure a viral load of <10(4) IU mL-1.
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PMID:Nucleic acid testing for emerging viral infections. 1222 Feb 57

Persistent infection with parvovirus B19 (B19) is an important treatable cause of anemia in HIV-infected patients. B19 has a tropism for erythroid progenitors and causes pure red cell aplasia (PRCA). The failure to produce neutralizing antibodies to the virus following B19 infection in immunodeficient persons may result in persistent viremia and chronic PRCA (B19-PRCA). The seroprevalence rates for B19 in unselected persons with HIV infection are high, similar to those seen in the general population. Reports of B19-related anemia in HIV infected patients, however, are infrequent. A partial explanation may be that B19-PRCA is predominantly a complication associated with advanced immunodeficiency. The condition is probably underdiagnosed as well. The finding of an unexplained normocytic anemia with absent reticulocytes, in an afebrile HIV-infected patient without renal dysfunction suggests a diagnosis of B19-PRCA. The diagnosis is established when the following criteria are met: (1) bone marrow biopsy showing PRCA, (2) serum or bone marrow positivity for B19 DNA by PCR or dot-blot hybridization, and (C) no alternate explanation for the PRCA. Serological methods are unreliable for the diagnosis because these patients often lack IgM and IgG antibodies to B19. Nearly all patients with B19-PRCA respond to treatment with intravenous immunoglobulin (IVIg) with a rise in the hemoglobin to levels appropriate for the clinical condition of the patient. An alternative explanation for the anemia must be sought in patients not responding to IVIg. Most patients with CD4+ T-lymphocyte counts of < or = 100 cells/mm3 relapse to anemia, usually within 6 months of IVIg therapy. Such patients must be retreated with IVIg 2 g/kg given over 2 to 5 days. The routine use of maintenance IVIg 0.4 g/kg q 4wk may be considered in these patients to prevent relapse.
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PMID:Parvovirus B19-related anemia in HIV-infected patients. 1224 Aug 88

The reconstitution of blood and its components is hampered by factors of compatibility, availability, and the risk of transmission of infectious diseases. Protozoal agents such as plasmodium malariae and trypanosoma cruzi are only regionally relevant. Bacterial transmissions are easy to prevent and treat. Antibody, antigen, and nucleic acid screening have been implemented to prevent transmission of blood-borne viruses. Transfusion-relevant viruses include hepatitis B and C virus (HBV and HCV), human immunodeficiency virus (HIV), human T leukemia virus (HTLV-I), and in certain circumstances, parvovirus B19, hepatitis A virus (HAV), and cytomegalovirus (CMV). Of great concern is the possible transmission of prion protein causing transmissible spongiform encephalopathy. Of future interest will be whether other viruses such as Nipah and Hendra virus are blood-borne and whether viruses such as TT, SEN, and GBV-C are involved in diseases or their progression, while not causing hepatitis.
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PMID:Virus safety of human blood, plasma, and derived products. 1237 92


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