[Spanish cohort of naïve HIV-infected patients (CoRIS): rationale, organization and initial results].

Objective: To describe the methodology and baseline results of the Spanish cohort of naïve HIV-infected patients included in the Research Network on HIV/AIDS (CoRIS).

Methods: CoRIS is a multicenter, hospital-based prospective cohort of HIV sero-prevalent, retroviral-naïve subjects, over 13 years old, and seen at 17 hospitals in 8 of the 17 Autonomous Regions in Spain from January 2004 to October 2005. The socio-demographic characteristics, as well as epidemiological, clinical, laboratory and treatment data were recorded, and biological samples were collected at baseline and during follow-up.

Results: A total of 1,591 subjects have been included in CoRIS; 24% are women, median age at cohort entry is 36 years, and 74% were diagnosed during 2004 or 2005. Twenty-seven percent came from countries other than Spain, mainly Latin-America (16%) and sub-Saharan Africa (5%). Thirty-two percent had completed secondary education and 16% university studies. The most frequent categories of transmission were men having sex with men (37%) and heterosexual sex (36%); only 21% were injection drug users. At cohort entry, median CD4 count was 317 cells/mm 3 and median viral load was 52,300 copies/mL; 18% were diagnosed with AIDS. Main AIDS-defining illnesses were Pneumocystis jiroveci pneumonia (6.1%), esophageal candidiasis (3.3%) and tuberculosis (extrapulmonary, 3.0% and pulmonary 2.7%). There were 35 deaths (2.2%). Thirty-three percent of patients gave a baseline sample to the BioBank.

Conclusions: CoRIS offers relevant information about the current epidemiological profile of HIV infection in Spain, where sexual transmission has become predominant. The type and amount of information obtained from clinical and epidemiological data collection together with biological samples demonstrate the viability of the project, which offers many possibilities for future research.