Comparison of analytical sensitivity of HIV diagnostic kits using dilutional panel

Abstract

An array of tests have been developed over a period of time for screening and diagnosis of HIV infection which include tests for detection of antigen and antibody , viral nucleic acid and the virus itself. Amongst the available tests, serodiagnosis by ELISA is widely being used. It offers a relatively inexpensive procedure with ease of performance and ability to effectively screen a large number of specimens. Our current study is designed to compare the performance of two different HIV diagnostic kits having different coated antigens using HIV dilutional panel. Kit X had synthetic peptides (3rd generation), and the Kit Y had recombinant antigens (2nd generation) coated on the microtitre plates. 10 HIV-1 plasma panel members which were collected from various blood banks were used for comparison of their performance. The plasma samples were diluted in human plasma (base matrix) negative for anti HIV, anti HCV, HBsAg, VDRL and HTLV I/II. Serial dilutions in the range of 10 to10,000 fold for each sample were used for this study. These kits were compared in terms of antibody titre which is defined as the dilution at which the sample OD to cut off (S/Co) value is 1. It was seen that Kit X is more sensitive as compared to Kit Y for all the HIV panel members. This indicates that Kit X had better analytical sensitivity performance as compared to Kit Y since the S/Co ~ 1.0 of Kit X is at a higher dilution (1:1000) than of Kit Y (1:100).Thus this indicates that dilutional panel can help the manufacturers to design a diagnostic kit which is able to detect the infection at an early stage of disease. It was seen that the S/Co ~ 1.0 of kit X at a higher dilution.