CD4 and syphilis: In unadjusted regression models, HIV infection did not increase risk of NCI [PR 0.99 (0.60–1.63)], but any latent HIV coinfection (including past history of hepatitis B infection, TB infection, or syphilis) increased the risk of NCI [PR 1.72 (1.04–2.86)], and a current CD4 absolute count of <500 cells/mm3 approached statistical significance [PR 1.64 (0.96–2.8)].