Antibodies against cyclic citrullinated peptides in infectious diseases--a systematic review

Rheumatoid arthritis (RA) is a disease characterized by symmetrical polyarthritis of the large and small joints, and in the majority of patients, there is a presence of the rheumatoid factor and erosions in the X-ray of the joints. More recently, the presence of anti-cyclic citrullinated peptide antibodies (anti-CCP) in this disease has been described, with diagnostic and prognostic value. Nevertheless, these antibodies have also been described in infectious diseases. The aim of the present study was to make a systematic review of the presence of antibodies against citrullinated peptides in infectious diseases. Search was conducted in the MEDLINE (1966 to 2010), Cochrane, SCielo, and LILACS databases, using the terms: "anti-CCP, anti-MCV, and infectious diseases"; "anti-CCP, anti-MCV, and virus"; "anti-CCP, anti-MCV, and mycobacteria"; "anti-CCP, anti-MCV, and tuberculosis"; "anti-CCP, anti-MCV, and leprosy"; "anti-CCP, anti-MCV, and leishmaniasis"; "anti-CCP, anti-MCV, and HIV"; "anti-CCP and HTLV"; "anti-CCP, anti-MCV, and Chagas disease"; "anti-CCP, anti-MCV, and Lyme disease", and the corresponding terms in Portuguese. Twenty-five publications were found, which dealt with anti-CCP and infection, and only one on anti-MCV and infection. Of these, 23 were cross-sectional and three cohort studies. Anti-CCP antibodies were found in various frequencies, reaching 37% in tuberculosis. In the other infections, it was a rare finding. In only one publication, anti-MCV was found in only one patient with hepatitis. Since infectious diseases are capable of running their course with osteoarticular symptoms, sometimes difficult to differentiate from RA, additional studies are necessary to define the performance of the test for the detection of anti-CCP antibodies in populations in which the frequency of such infections is high.