Immunological Features Of Systemic Lupus Erythematosus Research Articles

Implications of Endogenous Retroelements in the Etiopathogenesis of Systemic Lupus Erythematosus.

Systemic lupus erythematosus (SLE) is a heterogeneous autoimmune disease. While its etiology remains elusive, current understanding suggests a multifactorial process with contributions by genetic, immunologic, hormonal, and environmental factors. A hypothesis that combines several of these factors proposes that genomic elements, the L1 retrotransposons, are instrumental in SLE pathogenesis. L1 retroelements are transcriptionally activated in SLE and produce two proteins, ORF1p and ORF2p, which are immunogenic and can drive type I interferon (IFN) production by producing DNA species that activate cytosolic DNA sensors. In addition, these two proteins reside in RNA-rich macromolecular assemblies that also contain well-known SLE autoantigens like Ro60. We surmise that cells expressing L1 will exhibit all the hallmarks of cells infected by a virus, resulting in a cellular and humoral immune response similar to those in chronic viral infections. However, unlike exogenous viruses, L1 retroelements cannot be eliminated from the host genome. Hence, dysregulated L1 will cause a chronic, but perhaps episodic, challenge for the immune system. The clinical and immunological features of SLE can be at least partly explained by this model. Here we review the support for, and the gaps in, this hypothesis of SLE and its potential for new diagnostic, prognostic, and therapeutic options in SLE.

Differences by race, sex and age in the clinical and immunologic features of recently diagnosed systemic lupus erythematosus patients in the southeastern United States.

We examined the prevalence of clinical and immunologic features of systemic lupus erythematosus (SLE) by race, sex and age in a population-based study of 265 SLE patients. Patients fulfilled the American College of Rheumatology classification criteria. The median time between diagnosis and study enrollment was 13 months. The clinical and hematologic data were limited to occurrences up to 6 months after the diagnosis date, as documented in medical records. We used sera collected at study enrollment from 244 (92%) patients for serologic testing of autoantibodies. The associations between clinical and immunological features of SLE and age, sex and race were examined using logistic regression. The effect of each of these variables was examined adjusting for the other two demographic factors. Mean age at diagnosis was 6 years younger among African-Americans and other minorities compared with white patients (P < 0.01). Discoid lupus, proteinuria, anti-Sm and anti-RNP autoantibodies were more commonly seen in African-American patients, with odds ratios higher than 3.0. Photosensitivity and mucosal ulcers were noted less often in African-American patients. Proteinuria, leukopenia, lymphopenia and thrombocytopenia were approximately three times more common in men compared with women. The prevalence of oral or nasal ulcers and anti-DNA autoantibodies declined with age. The extent to which the differences we observed reflect genetic or environmental influences on the disease process should be investigated.

Systemic lupus erythematosus

Systemic lupus erythematosus (SLE) is the most common of the connective tissue disorders and can involve virtually any organ in the body. It is associated with pleuropulmonary manifestations in well over 50% of cases. Pleuritis with or without pleural effusion is the most common manifestation and can be particularly troublesome to manage but is rarely life-threatening. More serious manifestations in the lung include acute lupus pneumonitis with or without alveolar haemorrhage, chronic lupus pneumonitis and pulmonary hypertension. These all contribute significantly to overall mortality in SLE. The association between SLE and the antiphospholipid syndrome, leading to venous thrombosis and pulmonary embolism, is well recognized. Up to 20% of all cases of SLE present in childhood and many of these have pulmonary features at presentation or during the course of their illness. Sepsis is one of the main causes of death in SLE and pulmonary sepsis in these often immunocompromised patients contributes a significant proportion. Several drugs can produce a clinical syndrome that has many of the clinical and immunological features of SLE. Pleuritis may be seen in up to half of these cases of drug induced SLE. The development of SLE and conditions such as sarcoidosis or asbestosis in the same patient may represent a simple coincidence but there is some evidence for a closer association between these disorders.