Frequency of Mycoplasma hominis and Ureaplasma urealyticum infections in women with systemic lupus erythematosus Freqüência da infecção pelo Mycoplasma hominis e Ureaplasma urealyticum em mulheres portadoras de lupus eritematoso sistêmico

Ureaplasma urealyticum (UU) and Mycoplasma hominis (MH) have been detected in the urine of women with systemic lupus erythematosus (SLE). We evaluated the presence of these mycoplasma in the endocervix of women presenting SLE. A total of 40 SLE patients (mean age 40.2 years), and 51 healthy women (mean age 30.9 years), were studied. Endocervical swabs were cultured in specific liquid media for MH or UU, detected by a quantitative color assay, and considered positive at >103 dilutions. Statistical analysis was performed using the two-tailed Fisher test. UU was detected in 52.5 % of patients and in 11.8% of controls (p= 0.000059). MH was detected in 20% of patients and 2% controls (p=0.003905). Both mycoplasmas were detected in 7.3% patients and 0% controls (p<0.000001). The results reported here corroborate the association of the mycoplasma infection and SLE. Thus, these agents may stimulate the production of autoreactive clones. Key-words: Mycoplasma. Systemic lupus erythematosus. Mycoplasma hominis. Ureaplasma urealyticum. Genital infections. 1. Faculdade de Medicina de Ribeirão Preto da Universidade de São Paulo. Conselho Nacional de Desenvolvimento Científico e Tecnológico-CNPq, 2. Hospital das Clínicas da Faculdade de Medicina de Ribeirão Preto da Universidade de São Paulo. Financial Support: CNPq and FAEPA. Address to: Dra. Alcyone A. Machado, Faculdade de Medicina de Ribeirão Preto /USP. Av. Bandeirantes 3900, 14049-900 Ribeirão Preto, SP, Brasil. Phone: 55 16 633 0436, Fax: 55 16 633 6695 e-mail: [email protected] Recebido em 26/9/2000. Systemic lupus erythematosus (SLE) is an autoimmune disease of connective tissue involving various organs and having a broad spectrum of clinical presentation, with periods of exacerbation and remission. Several immunological alterations are involved in the disease. The disease predominates among young women and its etiology is unknown, probably being multifactorial. Genetic, hormonal, immunological and environmental factors have been implicated in its etiopathogeny. Among the environmental factors, we may mention the participation of sunlight, of medications and of infections induced by viruses or other microorganisms7 11 17. Mycoplasma hominis (MH) and Ureaplasma urealyticum (UU) belong to the family Mycoplasmatacea, which is considered to include the smallest free-living microorganisms in nature. Their size is intermediate between bacteria and viruses. They differ from the former by the lack of a cell wall and from the latter by the fact that they grow in cell-free media3 4 . The lack of a cell wall in microorganisms of the family Mycoplasmatacea permits their direct contact with host