The role of infectious diseases in the catastrophic antiphospholipid syndrome.

Catastrophic antiphospholipid syndrome (CAPS), also called "Asherson syndrome", is a variant of the antiphospholipid syndrome (APS) that occurs in less than 1% of APS cases. The etiology of CAPS is uncertain; however, several triggering factors have been recognized. The most common of these are infectious diseases, particularly those of the respiratory tract. CAPS pathogenesis is incompletely understood, but several theories have been proposed, such as the molecular mimicry theory, which describes the production of anti-ß2-glycoprotein I (GP1) antibody in response to infection. The process is complex and involves the activation of Toll-like receptor 4 (TLR-4), which triggers a cytokine storm, followed by endothelial alterations that induce a procoagulant state.

Socioeconomic status and organ damage in Mexican systemic lupus erythematosus women.

The objective of this cross-sectional study was to determine relationships between socioeconomic status and organ damage in Mexican systemic lupus erythematosus (SLE) patients. Demographic and clinical variables were assessed. Socioeconomic status was evaluated using the Graffar method and monthly household income. Lupus activity and organ damage were measured using the SLE disease activity scale, validated for the Mexican population (Mex-SLEDAI), and the Systemic Lupus International Collaborating Clinics/American College of Rheumatology (SLICC/ACR) scale. The 143 Mexican female SLE patients included (mean age 40.1 ± 8.9 years, mean disease duration 8.9 ± 6.3 years) had a mean monthly household income of $ 407.2 ± 326.5. According to the Graffar index, 18.9%, 52.5%, and 28.7% had high/medium-high, medium, and medium-low/low socioeconomic status, respectively. Organ damage was observed in 61 patients (42.7%). Patients with organ damage had lower monthly household incomes ($241.4 ± 152.4 vs. $354.8 ± 288.3) and were more frequently unemployed (57.3% vs. 35.3%; p = 0.01) than those without. Low monthly income was not associated with lupus activity or self-reported health status. In the adjusted multivariate analysis, low monthly income ( < $300) was associated with organ damage. In conclusion, low income may be associated with organ damage in Mexican SLE patients.

P-glycoprotein in autoimmune rheumatic diseases.

P-glycoprotein (Pgp) is a transmembrane protein of 170 kD encoded by the multidrug resistance 1 (MDR-1) gene, localized on chromosome 7. More than 50 polymorphisms of the MDR-1 gene have been described; a subset of these has been shown to play a pathophysiological role in the development of inflammatory bowel disease, femoral head osteonecrosis induced by steroids, lung cancer and renal epithelial tumors. Polymorphisms that have a protective effect on the development of conditions such as Parkinson disease have also been identified. P-glycoprotein belongs to the adenosine triphosphate binding cassette transporter superfamily and its structure comprises a chain of approximately 1280 aminoacid residues with an N-C terminal structure, arranged as 2 homologous halves, each of which has 6 transmembrane segments, with a total of 12 segments with 2 cytoplasmic nucleotide binding domains. Many cytokines like interleukin 2 and tumor necrosis factor alpha increase Pgp expression and activity. Pgp functions as an efflux pump for a variety of toxins in order to protect particular organs and tissues as the central nervous system. Pgp transports a variety of substrates including glucocorticoids while other drugs such as tacrolimus and cyclosporine A act as modulators of this protein. The most widely used method to measure Pgp activity is flow cytometry using naturally fluorescent substrates such as anthracyclines or rhodamine 123. The study of drug resistance and its association to Pgp began with the study of resistance to chemotherapy in the treatment of cancer and antiretroviral therapy for human immunodeficiency virus; however, the role of Pgp in the treatment of systemic lupus erythematosus, rheumatoid arthritis and psoriatic arthritis has been a focus of study lately and has emerged as an important mechanism by which treatment failure occurs. The present review analyzes the role of Pgp in these autoimmune diseases.