CD4 and chronic obstructive pulmonary disease: Several risk factors associated with IPD in PLWHA have been identified: age > 60 years and aboriginal ethnicity [8], education less than high school [8], smoking and alcoholism [4,9], intravenous drug use (IDU) [4,8,10], hepatitis C co-infection [8], chronic obstructive pulmonary disease (COPD) [8], low serum albumin, CD4 < 200 cells/mm3 [8], CD4 < 100 cells/mm3 [4,9], HIV RNA > 50.000 copies/mL, no use of ART [4], not having received 23-valent pneumococcal vaccine (PCV23) [4], and prior hospitalization [4,9].