1. HIV and STD Unit, Infectious Disease Service, Bellvitge University Hospital, L’Hospitalet del Llobregat, Barcelona, Spain;
2. Rheumatology Service, Bellvitge University Hospital, L’Hospitalet del Llobregat, Barcelona, Spain;
3. Clinical Laboratory, Bellvitge University Hospital, L’Hospitalet del Llobregat, Barcelona, Spain