Flow cytometry analysis with a new FITC-conjugated monoclonal antibody-3E12 for HLA-B*57:01 rapid screening in prevention of abacavir hypersensitivity in HIV-1-infected patients.

BACKGROUND: Rapid screening for the detection of HLA-B*57:01 in the prevention of abacavir hypersensitivity in HIV-1-infected patients is a hallmark for clinical services. OBJECTIVE: The aim of this work was to analyze the utility of flow cytometry with a new FITC-conjugated B-17 monoclonal antibody (mAb3E12) for HLA-B*57:01 screening in a Spanish cohort of 577 HIV-1+ individuals. METHODS: Cryopreserved peripheral blood mononuclear cell samples from HIV-1+ individuals were analyzed by flow cytometry with the mAb 3E12 that recognizes both HLA-B*57 and HLA-B*58 alleles (members of the group specificity, HLA-B17). Patients' DNA samples had been previously typed for HLA-B*57:01 with PCR-SSO or PCR-SSP and additional DNA sequencing (EPI Study). The results obtained by flow cytometry were compared with the results obtained by the DNA-PCR techniques. RESULTS: By flow cytometry, 46 samples (7.97%) were positive for HLA-B17, 530 (91.86%) were negative, and 1 (0.17%) was undetermined. All samples found negative by flow cytometry were negative for HLA-B*57:01 by DNA-PCR. Of the HLA-B17 positive samples, 31 (67.4%) were positive for HLA-B*57:01, 2 (3.25%) were positive for HLA-B*57:03, 11 (26.1%) were positive for HLA-B*58, and 2 (3.25%) were negative for both HLA-B*57 and HLA-B*58 antigens. The undetermined sample was negative for HLA-B*57 and HLA-B*58 alleles by DNA-PCR. CONCLUSIONS: This study shows that flow cytometry with mAb3E12 is a highly sensitive method (no false negatives) to implement prior to DNA-PCR analysis for rapid screening of HLA-B*57:01. Additional confirmation by molecular HLA typing method would be required in less than 10% of the cohort of HIV-1-infected individuals.

Prevalence of HLA-B*5701 in HIV-infected patients in Spain (results of the EPI Study).

BACKGROUND: A hypersensitivity reaction (HSR) is associated with abacavir (ABC), a nucleoside reverse transcriptase inhibitor. Genetic association of ABC HSR with the presence of HLA-B*5701 has been demonstrated in PREDICT-1 study, showing a prevalence of 5.6% in HIV-infected population. However the prevalence of this allele in HIV-infected patients in Spain has not been established yet. METHOD: This is a cross-sectional epidemiological study that included 1,198 patients in 74 centers that serve the HIV-infected population of Spain. HLA-B*5701 was checked both in the hospital lab and one central lab, showing an overall prevalence of this allele of 6%. RESULTS: HLA-B*5701 was most prevalent in Caucasian population (6.5%). Concordance between the local and central lab was very high for positive and negative results (95.7% and 99.3%, respectively). CONCLUSION: These aspects define this test as a useful tool for the management of HIV-infected patients.