Background: TCD4+ cells are target of HIV and an important parameter to determine immunodeficiency status. This laboratory test can only in limited centres, expensive and cannot be done in emergency unit. The absolute lymphocytes count can be alternative test that acceptable and has diagnostic value. Objective: This study aims to find correlation between absolute lymphocyte count and CD4+ count in children with HIV infection. Methods: We conducted a cross sectional analytical study at Haji Adam Malik Hospital, Medan, by taking patient medical record data from 2016-2020. Samples were excluded children <12 months, suffering from malignancy or bone marrow disease and receiving chemotherapy or steroids. Blood sample were collected and analysed on the same day according to the procedure. The Spearman correlation and linear regression analysis was performed. Results: A total of 304 haematological data met the inclusion criteria with an age range of 12-214 months. Overall strong correlation strength (r 0.668), moderate correlation at 12-35 months (r 0.441), strong correlation at 36-59 months (r 0.679), and strong correlation at ?60 months (r 0.714). The coefficient determination (R 2 ) of each is 0.414, 0.233, 0.481 and 0.488. Overall AUC area was 77.7%, age 12-35 months 53.2%, age 36-59 months 74.5% and age ?60 84.3%. Cut off point to determine the presence of an overall immunodeficiency 3.100/?l with a sensitivity of 64.8% and a specificity of 68.3%, 36-59 months 4.145/?l with a sensitivity of 71% and a specificity of 81.8% and ?60 months of 2.775/?l with a sensitivity of 78.6% and specificity of 79.1%. Conclusion: There is a correlation between the absolute lymphocyte count and the CD4+ count in children with HIV infection with increasing strength at a later age. The absolute lymphocyte count can be used as a predictor of CD4+ count.

HIV; CD4+; Absolute lymphocyte; Children