My veterinarian suspects that my cat has systemic lupus erythematosus. Please help me find information on lupus in cats. I want to know the symptoms, treatment, and prognosis. I can't find anything on-line; I've searched many areas. Please help.
Systemic lupus erythematosus, or SLE, is a rare disease in cats. Not much information is generally available about it. Lupus is a disease of the immune system. Antibody molecules against the affected cat's own tissues are produced, which ultimately cause an inflammatory response in the targeted tissues. The signs of SLE result from the inflammatory process; they are diverse because of the wide variety of organs affected. Additionally, primary signs of specific organ system damage caused by the SLE -- associated immune complexes may be present.
The principal signs of SLE include chronic skin changes, nonerosive polyarthritis, polymyositis (muscle inflammation), glomerulonephritis (a specific inflammatory kidney disorder), and reductions in certain blood cell populations. Most cats will be depressed, will have loss of appetite and weight loss, and may also have a fever. Chronic skin manifestations may include redness, blisters, and itching. The arthritis of SLE typically involves multiple joints in a symmetric pattern; unlike other forms of arthritis, the joint involvement in lupus does not usually cause destruction of cartilage. Abnormally low numbers of red and white blood cells (anemia and leukopenia, respectively) and low numbers of platelets (thrombocytopenia) occur frequently in SLE. Although the reduction in these blood cell lines is not specific for SLE alone, the presence of low blood cell populations is an important diagnostic clue for this disease.
Others signs of SLE may include inflammation of the heart (myocarditis) and linings of the heart and lungs (pericarditis and pleuritis, respectively). The nervous system is sometimes affected; seizures and altered states of consciousness or behavior may occur.
Diagnosis is reached with a positive combination of clinical signs and laboratory diagnostics. A complete blood count (CBC) will reveal anemia and other blood cell disorders. A blood chemistry panel and urinalysis may demonstrate nonspecific changes consistent with SLE. Several tests for SLE are available, including the antinuclear antibody (ANA) test and the lupus erythematosus (LE) cell test. However, test results are highly interpretative, and must be evaluated cautiously. Cats with elevated levels of circulating lupus-associated antibodies (ANA titers) do not always have lupus; other conditions may result in elevated ANA titers as well. Additionally, some cats with lupus will not have an elevated ANA titer. Unfortunately, there is no single, definitive test for SLE. Tissue biopsies may display changes characteristic of immune-mediated disease.
Treatment involves suppressing the immune system and the resultant tissue inflammation. Corticosteroids, such as prednisone, are the mainstay of treatment. Other immunosuppressive agents may be required to achieve a clinical remission; life-long treatment is expected. Organ system dysfunction resulting from SLE should be addressed as well. The prognosis is considered guarded. Progressive organ dysfunction and failure indicate a poor prognosis.
If your cat has been diagnosed with lupus or is suspected of having this problem, you may wish to speak with your veterinarian about referral to a veterinary specialist in internal medicine, or dermatology, if skin changes predominate.
05/04/06
