Human immunodeficiency virus DNA amplification and serology in blood donors

Abstract

The significance of indeterminate screening antibody test for human immunodeficiency virus (HIV) serology is still difficult to evaluate, especially in low-risk populations. One hundred twenty-seven blood donors with an initially reactive screening test for HIV antibodies were enrolled in this study. The sera of 95 of these blood donors were reactive on repetition of the test, and none had detectable circulating p24 antigen. Western blot (WB) analysis of the repeatedly reactive sera was as follows: 9 positive, 31 indeterminate, and 55 negative. One of the blood donors with indeterminate WB later presented a seroconversion. On subsequent control 3 to 12 months later, the sera from donors with indeterminate or negative WB did not present any parameters that may indicate a seroconversion. DNA was purified from citrated blood collected from the 127 blood donors at the time of the initial antibody screening. Five micrograms of each DNA sample corresponding to 7 x 10(5) nucleated white blood cells was amplified by polymerase chain reaction (PCR) in the presence of oligonucleotides (primers) corresponding to a highly conserved segment of the pol gene. The detection of amplified DNA was achieved by dot blot and Southern blot using appropriate 32P-labeled oligonucleotides. Ten DNA samples were positive, 9 corresponded to blood donors with a positive HIV serology, and 1 to the blood donor who later presented a seroconversion. These results confirm the sensitivity of the PCR for the diagnosis of HIV infection; they also suggest that repetition of the serology at 3- to 12-month intervals is a valuable procedure for the control of HIV infection status in blood donors.

Blood Donations Indeterminate in HIV‐1 Western Blot Analysed by IgM Immunoblot and Polymerase Chain Reaction

“…Our findings correspond to other reports dealing with the interpretation of repeatedly indeterminate WB results [31,36,37]. According to these reports only 1 of a total of 142 donors tested by PCR was infected with HIV-1, showing that the cases of indeterminate serologic results which can be attributed to HIV-1 are rare but do exist.…”

Enzyme-linked oligosorbent assay for detection of polymerase chain reaction-amplified human immunodeficiency virus type 1

“…It has been shown that the sensitive detection of HIV-1 nucleic acids by polymerase chain reaction (PCR) amplification (34) of conserved sequences of HIV-1 proviral DNA is of interest for the diagnosis of HIV-1 infection (11, [23][24][25]40) and could be a potential parameter for clinical status (9) or treatment evaluation (2). The variability of the viral genome, which can lead to problems of specificity and sensitivity, has encouraged many groups to develop primer pairs in various conserved regions of the viral genome, generally gag and/or pol (7,23,25,30,31), less frequently env and/or the long terminal repeat (7, 30), or nef or vif (7).…”

HIV-1/2 indeterminate Western blot results: follow-up of asymptomatic blood donors in Belo Horizonte, Minas Gerais, Brazil

“…A vast number of conditions have been reported by different authors as being associated with inde-terminate WB results. They include: systemic lupus erythematosus 1,2,4 , presence of rheumatoid factor and polyclonal gamopathy 1,2 , antibodies to DR-HLA 5,16 , cross-reactivity to core proteins of other retroviruses like Bovine Immunodeficiency Virus 7,10,19 , Mycobacterium leprae infection 12 , heat inactivation of serum samples 6 , in vitro hemolysis, elevated bilirrubin levels (Cambridge Biotech HIV WB kit insert) and tetanus vaccination 1,2 .…”

“…The implementation in blood banks of new tests to recently discovered viruses leads to uncertainty on how to interpret the results, specially if they are indeterminate 4 . The screening of volunteer blood donors for antibodies to the human immunodeficiency viruses (HIV-1/2) is usually done with enzyme immunoassay tests, followed by a supplemental technique if repeatedly reactive 3,16 . The supplemental tests routinely used include Western blot (WB), immunofluorescence and particle agglutination assays.…”