Maggi P, et al. - The Coordinamento Italiano per lo Studio di Allergia e Infezioni da HIV (CISAI) conducted a cross-sectional analysis on adult subjects attending HIV-outpatient facilities in order to describe co-morbidity and multi-morbidity, their clustering mode and the potential disease-disease interactions in an Italian HIV cohort. Among 1087 patients enrolled in the study (mean age 47.9 ± 10.8), more than 50% were multi-morbid and about 30% had three or more concurrent comorbidities. Associations that were most recurrent comprised: 1) dyslipidemia + hypertension (237, 21.8%); 2) dyslipidemia + chronic obstructive pulmonary disease (188, 17.3%); 3) chronic obstructive pulmonary disease + antibodies for hepatitis C virus (141, 12.9%). Older age, higher body mass index, current and former smoking, Center for Diseases Control stage C and longer antiretroviral therapy duration were noted to be correlated with multi-morbidity. Researchers suggest addressing the phenomenon of clusterization timely and detecting all the patients at risk of disease-disease interactions as mandatory in view of the aging of PLWH, their persistent exposure to chronic inflammation and the possible effects of HAART.