Systemic Lupus Erythematosus

What is the LES?

The term lupus was historically used for the first time to indicate a lesion to the face that, with a certain imagination, was considered similar to that caused by the bite of a wolf.

LES ( Systemic Lupus Erythematosus ) is a systemic inflammatory disease, ie spread to the whole body, which manifests itself with extremely varied clinical pictures. It is characterized by the presence of autoantibodies, that is antibodies turned against the normal constituents of the organism, like some components of the tissues, in particular the cell nucleus. The most characteristic autoantibody is turned against DNA.

Systemic Lupus Erythematosus affects individuals of all races, has a clear preference for the female sex (8-9 times more frequent in women than in men), and occurs at very different ages (from 0 to 76 years) with a maximum of frequency between 10 and 40 years.

Insights

Causes

The causes of Systemic Lupus Erythematosus are not known, but it has been seen that it depends on several factors (multi-factorial):

• Genetic factors : a certain familiarity with this disease is well known.

• Environmental factors : in about one third of patients, the appearance of Systemic Lupus Erythematosus or its exacerbation is preceded by prolonged exposure to the sun or ultraviolet rays (tanning lamps).

• Drugs : some drugs can cause the onset of lupus-like manifestations (hydralazine, procainamide, alpha-methyldopa, PAS, anticonvulsants and D-penicillamine). The clinical picture of these forms is very similar to that of classical but less severe lupus.

• Action of viruses : an important role is assumed by viruses (rubella, paramixovirus) in the onset of Systemic Lupus Erythematosus .

• Role of sex hormones : the fact that SLE is nine times more common in women than in men appears to be related to the ability of sex hormones to modulate the immune response, with stimulatory effects on the onset of autoimmune diseases, therefore also of SLE, by female sex hormones, especially estrogens, and inhibitors by male ones, especially testosterone.

The presence of different types of autoantibodies is the main feature of Systemic Lupus Erythematosus . Among these are very important those directed against the constituents of the cell nucleus, called anti-nucleus antibodies (ANA or ANF in abbreviation). These autoantibodies are of different types and react against molecules present in the nucleus, especially DNA, but also against the proteins of the nucleus, called histones. There are also other autoantibodies directed against substances belonging to the cytoplasm of cells, especially RNA molecules, and called anti-cytoplasmic antibodies, and finally antibodies against coagulation proteins, called lupic anticoagulants, against red blood cells, lymphocytes, platelets, and against specific molecules belonging to the various organs (thyroid, liver, adrenal glands, stomach, muscle).

Once it was thought that these autoantibodies could directly destroy their targets; today, instead, it has been seen that they are unable to penetrate living cells, because they are blocked by the outer membrane. However they bind to the DNA of the cells forming structures called complex antigen (represented by DNA) - antibody (which is the autoantibody of the LES). These complexes can be deposited in various sites, in particular in the kidney, causing serious injuries that are the basis of the symptoms of Systemic Lupus Erythematosus .