Characterization of HIV RNA in Blood Donor Possessing Serological Test Indeterminate

Indeterminate results of serological HIV test have been found in Indonesia. The screening procedure is following the prescribed by WHO for screening of blood donors which is based on 3 different serological HIV test during screening of blood donors. Discordant results are interpreted as indeterminate. In order to find the cause of the indeterminate results, we conducted RT-PCR detection of HIV RNA in samples from blood donors with indeterminate serological HIV-test. Plasma samples showing indeterminate results by serological testing from blood donor were collected from Blood Transfusion Service of Indonesian Red Cross and subjected to confirmatory test by using western blot. Test of 40 samples showed that 90% of the samples remain indeterminate. Most of the indeterminate results were caused by the reactivity towards p24 antigen. RT-PCR targeted at LTR, pol, env and p24 region of HIV was performed to detect the presence of HIV RNA. Primer were consequently designed to amplify these regions. Preliminary results showed 1/35 24/32 (75%) positive LTR, 4/31 (12%) positive pol and 1/3 (33%) positive env. Amplification in p24 region showed that bands found have lower size than expected. Sequencing was performed to confirm these findings. The results suggest that further exploration should be performed in order to understand the magnitude of problem regarding HIV-RNA positivity in indeterminate sample by serological test to determine future direction such as the necessity to obtain information regarding the influence of circulating HIV strain in Indonesian population towards accuracy of HIV diagnostics