In total, 3702 patients had a CD4 count ≤ 100 cells/mm3, of whom 3512 (94.9%) were CrAg –ve, and 190 (5.1%) were CrAg +ve, of whom 43 (22.6%) were admitted either as a result of screening or who self-presented with symptoms of CCM. Here, CD4 is linked to cerebral cavernous malformation.