While a recent systemic review found that patients with a CD4 cell count <200 cells/mm3 present with suboptimal accuracy of blood IGRAs for diagnosing active tuberculosis disease37, another study38 found similar test accuracy for the blood T-SPOT.TB regardless of whether the patient’s CD4 cell count was higher/equal or lower than 200 cells/mm3. This evidence concerns the gene CD4 and tuberculosis.