Claudia Mendoza-Pinto

Etiopathogenesis of Behcet's disease.

Bechets disease (BD) is an inflammatory, multi systemic disease with spontaneous remissions and relapses similar to various autoimmune diseases. BD leads to organ damage, including the eyes, skin, joints, etc., which produces various clinical manifestations. The central histopathologic characteristic is systemic vasculitis with perivascular inflammatory infiltrates. The etiopathogenesis is unknown, although immunological abnormalities, possibly induced by susceptible microbiological pathogens, have been postulated.

Immunopathogenesis of vitiligo

Vitiligo is a common depigmenting disorder which may have devastating psychological and social consequences and is characterized by the presence of circumscribed white macules in the skin due to the destruction of melanocytes in the epidermis. Various hypotheses have been proposed to explain the pathomechanisms involved in this disease, and studies have shown the participation of autoimmune processes in the pathogenesis of vitiligo. Cellular and humoral immunities have been implicated in the development of vitiligo and their role continues to be investigated. Peripheral blood and skin biopsies of patients with vitiligo show that T-cells, mononuclear cells, various pro-inflammatory cytokines, and auto-antibodies can damage melanocytes. Further research is required to determine whether autoimmunity is the main mechanism of vitiligo or only a consequence.

Anti-CD20 therapy in patients with refractory systemic lupus erythematosus: a longitudinal analysis of 52 Hispanic patients

The objective of this study was to investigate the efficacy and safety of anti-CD20 treatment in Hispanic patients with refractory systemic lupus erythematosus and to determine whether baseline parameters predict disease flare. Fifty-two patients with systemic lupus erythematosus, 13 with active lupus nephritis, eight with thrombocytopenia, three with leukocytopenia, 25 with severe musculoskeletal involvement and three with skin involvement) refractory to conventional therapy were treated with anti-CD20 treatment (rituximab; MabThera®, Roche) plus ongoing immunosuppressive treatment. Disease activity was assessed monthly using the SLEDAI validated for the Mexican population with a follow-up period of 6 months. At 6 months of follow-up, significant clinical improvements were detected, with a reduction in the global SLEDAI validated for the Mexican population score. Five of the 13 patients with lupus nephritis (38.4%) had a complete renal response and five (38.4%) had a partial response. Rituximab was also effective in patients with autoimmune thrombocytopenia, inducing a significant increase in platelet counts (p = 0.012). Nineteen of 25 patients with severe musculoskeletal involvement had remission of arthritis. Only one of the three patients with skin involvement had no lesions at 6 months. Rituximab treatment also allowed a reduction of the oral prednisone dose in the majority of patients. No baseline predictors of flare were found. Treatment was discontinued after the first infusion in two patients due to serum sickness and in another due to pulmonary infection. In conclusion, the addition of rituximab to conventional immunosuppressive therapy may be an effective strategy for lupus nephritis, autoimmune thrombocytopenia and inflammatory polyarthritis in patients with refractory systemic lupus erythematosus. Lupus (2010) 19, 213—219.

Use of rituximab in patients with systemic lupus erythematosus: An update

Systemic lupus erythematosus (SLE) is a chronic, occasionally life threatening, multisystem disorder. Patients suffer from a wide group of symptoms and have a variable prognosis that depends of the severity and type of organ involvement. The clinical manifestations include fever, skin lesions, arthritis, neurologic, renal, cardiac, and pulmonary disease. The pathogenesis of this serious multisystem autoimmune disease is based on polyclonal B cell immunity, which involves connective tissue and blood vessels. The novel biologic therapies have raised hope for more effective and safer treatment for SLE. Although definitive studies are still under development, the impressive preliminary results of therapies specifically targeting B cells and the signaling pathways involved in B-T-cell interactions suggest that the depletion of memory cells accounts, at least in part, for the clinical efficacy of rituximab therapy in patients whose disease is resistant to other immunosuppressive therapies. However these findings, although provocative, require further investigation in larger cohorts.

Treatment of Raynaud's phenomenon.

Raynauds phenomenon is an episodic vasospasm of the peripheral arteries, causing pallor followed by cyanosis and redness with pain and sometimes paraesthesia, and, rarely, ulceration of the fingers and toes. Primary or idiopathic Raynauds phenomenon (Raynauds disease) occurs without an underlying disease. Secondary Raynauds phenomenon (Raynauds syndrome) occurs in association with an underlying disease. Initially conservative, non-pharmacologic approach is important for these patients, although pharmacologic therapy may ultimately be necessary. Advances in vascular physiology have showed the role of the endothelium as well as endothelium-independent mechanisms in the altered vasoregulation of Raynauds phenomenon. This has opened promising therapeutic avenues, and it is likely that therapies targeted towards specific pathophysiologic steps become available in the near future.

Diagnosis and classification of Susac syndrome

Susac syndrome (SS) is an autoimmune disease characterized by the clinical triad of encephalopathy, branch retinal artery occlusions and neuro-sensorial hearing loss; it is due to a microangiopathy affecting the precapillary arterioles of the brain, retina and inner ear. SS is characterized by typical radiological features on magnetic resonance imaging (MRI) which, together with clinical symptoms, may permit a diagnosis. Branch retinal artery occlusions (BRAOs) are best evaluated using fluorescein angiography (FA) which may show the typical multifocal fluorescence. SS is an autoimmune endotheliopathy that requires treatment with immunosuppressive agents: steroids, azathioprine, mycophenolate mofetil, methotrexate, cyclophosphamide and intravenous immunoglobulin, usually in combination. Plasma exchange is also useful. In addition, antiplatelet agents may be a useful adjunct. Correct immunosuppressive therapy results in significant clinical and radiological improvement. An early diagnosis and treatment are important to delay the disease progression and prevent permanent disability.

Infections and the antiphospholipid syndrome.

Currently, the origin of autoimmune diseases is considered to be multifactorial. Genetic predisposition, immune system malfunction or even backfire, hormonal regulation, and environmental factors, i.e. infections, all play important roles in the pathogenesis of autoimmune diseases such as the antiphospholipid syndrome (APS). New drugs and strategies aimed at preventing infections could further improve the outcome of APS and other autoimmune diseases.

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.

Health related quality of life in Mexican women with systemic lupus erythematosus: a descriptive study using SF-36 and LupusQoL©

The LupusQoL© questionnaire is a disease-specific health related quality of life (HRQOL) instrument for adults with systemic lupus erythematosus (SLE). The Short Form-36 (SF-36) is a generic instrument that captures the physical, psychological, and social impact. We conducted a descriptive study of women aged ≥ 18 years attending our Lupus Clinic. HRQOL was assessed by applying the LupusQoL© and SF-36. Lupus activity was measured using the Mexican Systemic Lupus Erythematosus Disease Activity Index (Mex-SLEDAI) and chronic damage using the Systemic Lupus Collaborative Clinics Damage Index (SDI). Data were analyzed using descriptive statistics, the chi-square test and Pearson’s product moment correlation coefficient. A total of 127 patients were included with a mean age of 40.5 ± 12.6 years. The mean disease duration was 8.2 ± 5.6 years, the mean disease activity score was 2.4 ± 3.0, and the mean SDI score 0.77 ± 1.06. The mean SF-36 score was 58.1 ± 21.1 and the mean LupusQoL© score was 69 ± 22.7. The correlation between global scores of the SF-36 and LupusQoL© was rho = 0.73 (p < 0.001). The correlation between lupus disease activity and the SF-36 and the LupusQoL© was −0.26 (p = 0.003) and −0.25 (p = 0.004), respectively. The correlation between the SDI and the SF-36 and the LupusQoL© was −0.28 (p = 0.001) and −0.38 (p < 0.0001), respectively. In conclusions: both LupusQoL© and SF-36 were useful instruments in assessing HRQOL in Mexican lupus female patients. The usefulness of the LupusQoL© should be evaluated in lupus patients with moderate to severe disease activity.

Primary antiphospholipid syndrome in Latin American mestizo patients: clinical and immunologic characteristics and comparison with European patients

A great variety of clinical and immunological features have been described in patients with the antiphospholipid syndrome (APS), but information on their prevalence and characteristics in Latin American mestizo patients with the primary APS is scarce. To analyze the prevalence and characteristics of the main clinical and immunological manifestations in a cohort of patients with primary APS of mestizo origin from Latin America and to compare them with the European white patients, clinical and serological characteristics of 100 patients with primary APS from Colombia, Mexico, and Ecuador were collected in a protocol form that was identical to that used to study the “Euro-Phospholipid” cohort. The cohort consisted of 92 female patients (92.0%) and eight (8.0%) male patients. They were all mestizos. The most common manifestations were deep vein thrombosis (DVT; 23.0%), livedo reticularis (18.0%), migraine (18.0%), and stroke (18.0%). The most common pregnancy morbidity was early pregnancy losses (54.1% of pregnancies). Several clinical manifestations were more prevalent in the Latin American mestizo than in the European patients (transient global amnesia, pulmonary microthrombosis, arthralgias, and early pregnancy losses) and vice-versa (DVT, stroke, pulmonary embolism, and thrombocytopenia). Latin American mestizo patients with primary APS have a wide variety of clinical and immunological manifestations with several differences in their prevalence in comparison with European white patients.