Use of DNA amplification methods for clinical diagnosis in autoimmune diseases

Increased expression of Epstein-Barr virus in primary biliary cirrhosis patients

Peripheral blood mononuclear cells (PBMC, n = 26), formalin-fixed paraffin-embedded liver tissues (n = 11) and saliva (n = 15) of primary biliary cirrhosis (PBC) patients were used for the detection of Epstein-Barr virus (EBV) sequences by polymerase chain reaction (PCR) assay. The semiquantitative analysis of EBV-DNA was also carried out in a reconstructive experiment using an EBV-infected cell line. The PBMCs of PBC patients showed increased levels of EBV-DNA (61%) in contrast to chronic active hepatitis patients (19%), liver cirrhosis patients (14%) and healthy individuals (11%). Furthermore, formalin-fixed paraffin-embedded liver tissues, as well as saliva from PBC patients, also demonstrated increased levels of EBV-DNA when compared to healthy individuals and those with other liver diseases. The increased levels of EBV-DNA in the PBMC, liver tissue and saliva of the PBC patients suggest that those patients may have a depressed immune function against EBV infection.

Laboratory methods for early detection of human immunodeficiency virus type 1 in newborns and infants

Cumulative data on serological testing of newborns and infants have shown that (i) maternal and newborn anti-HIV-1 IgG titers are high at delivery, which may explain the persistence of antibody in the infants of seropositive mothers; (ii) in some situations, serial HIV-1 antibody testing may identify infected infants; and (iii) detection of anti-HIV-1 IgA or IgM is specific for infection but the sensitivity of this assay may be compromised in certain situations, such as when infected infants are hypogammaglobulinemic or when the rise and fall of HIV-1-specific IgM synthesis following acute infection has been completed before delivery of the infant. Cumulative data on PCR, viral culture, and tests for antigen in newborns and infants have shown that (i) among all age groups, viral culture is probably the most specific test available for detection of HIV-1, as PCR and the p24 antigen test may (though rarely) give false-positive results; (ii) the sensitivity of these tests increases in the order of antigen, culture, and PCR, with relatively insensitive results in the first 3 months of life for all of these tests; (iii) the sensitivity of all of these tests improves and approximates 90 to 100% when infants over 6 months of age are tested; and (iv) data regarding the sensitivity, specificity, and usefulness of these virological assays in infants under 3 months of age are very scant and inconclusive.

Evaluation of clinically normal appearing skin for systemic infectious diseases in human immunodeficiency virus seropositive patients

The observation of a human immunodeficiency virus (HIV)-infected patient with cutaneous ulcers which contained both fungal and viral pathogens, and in which the fungal organisms were grown in culture yet could not be demonstrated microscopically, suggested the possibilities: 1) that the skin lesions might have been primarily caused by the viral pathogen, and 2) that the concurrent presence of that fungal pathogen was coincidental and perhaps secondary to fungemia. Assuming that these postulates are valid, it is reasonable to hypothesize that fungal organisms would have been detected if perilesional or distal, clinically normal appearing, skin had been evaluated. This hypothesis could be further assessed by performing a prospective study of clinically normal appearing skin for pathogens of suspected systemic infectious diseases in HIV seropositive patients. Since the quantity of infectious pathogens in nonlesional skin may be limited, it might be difficult to grow the organisms in culture or demonstrate them microscopically using standard methods. Therefore, in addition to routine cultures and histologic evaluation, immunohistochemical techniques using monoclonal antibodies to pathogen antigens and DNA amplification techniques based upon the polymerase chain reaction should be used to enhance the detection of the infectious pathogens.