Journal of AIDS & Clinical Research

Many people living with Human Immunodeficiency Virus (HIV) infection receive treatment with nucleoside reverse transcriptase inhibitors. This study’s objective was to evaluate whether treatment with lamivudine and emtricitabine can result in an elevated Mean Corpuscular Volume (MCV). This was a retrospective cohort study of people who were newly diagnosed with HIV infection and received treatment with lamivudine and/or emtricitabine. MCV is already a part of blood tests routinely performed in the care of people living with HIV infection. This study evaluated a difference in individual person’s MCV from prior to their anti-retroviral treatment (ART) and post-ART. Between January 2011 and June 2020, 282 people were newly diagnosed with HIV infection. 226 (80%) received emtricitabine, 45 (16%) received lamivudine and 11 (4%) received emtricitabine and lamivudine sequentially.  Overall, the median MCV increased by 3.5 (IQR 2-5) fL. The median MCV increase was 3 (IQR 2 to 5) fL in the emtricitabine group, 5 (IQR 3 to 7) fL in the lamivudine group and 5.5 (IQR 4 to 6) fL in the sequential group. There was a greater MCV increase in the lamivudine group compared with the emtricitabine group (p<0.001). Across all groups, seven people (2.5%) developed a macrocytosis (MCV ≥ 100 fL). While the increase in MCV was relatively modest and only a small percentage of people developed a macrocytosis, clinicians should be aware that treatment with lamivudine and to a somewhat lesser extent emtricitabine does result in an increased MCV when compared with baseline.