Systemic Lupus Erythematosus (SLE): A General clinical Overview, Pathology And Clinical Features
Butterfly And Malar Rash
A General Overview
SLE is an inflammatory disease of autoimmune nature involving the connective tissue of several organs systems and associated with a variable course.
This disease is seen all over the world. In India especially, it is not uncommon. Both sexes are affected, but females predominate. The exact etiology is unknown but the evidence suggests that the condition results from severe disturbances of immune regulation, with production of several autoimmune antibodies and immune complexes. Suppressor T-lymphocyte function is diminished. B-lymphocytes are overactive and consequently several autoantibodies belonging to IgG and IgM classes are produced. The autoantibodies combine with their antigens to form immune complexes which are deposited in various tissues resulting in inflammatory changes. Formation of immune complexes takes up serum complements C3 and complexes takes up serum levels of C3 and C4 are reduced. Primary factors responsible for initiating the immunological disturbance are not clearly definable.
Drugs and viral infections have been implicated in some cases. Genetic factors probably play an important role in some cases. This is evidenced by the simultaneous occurrence of the disease in monozygotic twins, higher incidence of SLE and other connective tissue disorders in the relatives of SLE patients and the presence of several auto-antibodies and low serum complement levels in many of them. HLA types B6 and DR3 and inherited deficiency of C1, C4 and C2 complement are known to be associated with a higher incidence of SLE.
Viral and bacterial infections, drugs like sulphonamides, pregnancy, puerperium and exposure to sunlight precipitate the acute attack.
The lesions of SLE are widespread and all tissues may be affected. Basically, four types of histological pictures are seen. These are fibrinoid changes, collagen sclerosis, formation of hematoxylin bodies and inflammatory changes in arterioles and capillaries. Tissue damage occurs in two different ways. These are:
- Direct cytotoxicity (type II reaction) caused by antibody and complement, e.g; brain damage and abortion, and
- Type III immune reaction caused by immune complexes and complement, e.g. renal and vascular lesions.
Pain In The Hand
The disease is more common in women, in the second and third decades. The presenting symptoms are arthritis, fever, and skin lesions, though diverse clinical features may be present.
Arthritis and Arthralgia: The conditions occur in 90% of subjects with SLE in the early stages. Large joints are affected more than others. Severity of joint involvement varies widely. Permanent deformities do not occur.
Skin Lesions: These occur in 65% of patients at some stage or other. The classical lesion is the erythematous, photosensitive, butterfly rash affecting the cheeks and nose and this is diagnostic. Discoid lupus, maculopapular rashes and purpura may occur in some. Frontal baldness may develop. Alopecia occurs due to breaking up the hair. Painful ulcers may develop in the mouth and pharynx. Discoid lupus is the form in which the only manifestation of the disease is confined to the skin for a few years. The lesions show scaling, atrophy, telangiectasis and keratotic plugging. They heal with considerable scarring. Some patients develop systemic lupus.
These are not all the clinical features of systemic lupus erythematosus, as it manifests on the respiratory system, kidney, central nervous system, muscles, blood and more. These would be discussed in the next hub.
© 2014 Funom Theophilus Makama