Polymyositis: a case history approach to the differential diagnosis and treatment.

A wide range of conditions can mimic polymyositis. Thus, diagnosing this condition can be a challenge. Although no single criterion is diagnostic of polymyositis, the following criteria have been proposed and widely used: (1) symmetric proximal muscle weakness; (2) characteristic violaceous rash on the hands, elbows, and knees; (3) increased muscle enzymes in the serum; (4) characteristic electromyographic findings (insertional activity, fibrillation potentials, motor unit potentials of increased frequency and decreased duration, and normal conduction velocity in nerves); and (5) muscle biopsy specimen with characteristic inflammatory and myopathic changes. Although polymyositis primarily involves muscle, up to 20% of patients may have extramuscular problems. The main treatment for polymyositis is high-dose corticosteroids. In corticosteroid-resistant patients, methotrexate is often effective. In this report, case histories are presented to highlight the usefulness and the limitations of the common diagnostic criteria for polymyositis.

Polymyositis-dermatomyositis and malignant lesions: does an association exist?

To examine the purported association between polymyositis-dermatomyositis and malignant lesions, we identified all patients with histopathologically proven polymyositis-dermatomyositis examined at our institution from 1965 to 1974. For each patient, a control subject was selected, matched for age, sex, race, year and department of clinical evaluation, and geographic area of residence. Although the proportion of patients who ever had a diagnosis of malignant disease (25%) was greater than that for controls (17%), the difference was not statistically significant (P = 0.14). The slight excess of cancer seen among patients was contributed by the most distant referrals and may best be explained on the basis of referral bias. No clinical differences were found between patients with polymyositis-dermatomyositis who had a malignant neoplasm and those who did not, and intensive clinical investigation to exclude "occult" underlying malignant growths did not seem to be cost-effective. Although the present study does not prove that there is no association between polymyositis-dermatomyositis and malignant lesions, the existence of a clinically significant relationship seems unlikely.

Anti-type II collagen antibodies in rheumatoid arthritis. The influence of HLA phenotype.

Antibodies to native chick and bovine Type II collagen were measured by radio immunoassay, in 83 rheumatoid arthritis (RA) patients and 14 normal controls. Anti-chick Type II collagen and anti-bovine Type II collagen antibodies were found in 48% and 43% of RA patients, respectively. A strong correlation of antibodies to chick and antibodies to bovine collagen was described, suggesting cross-reactivity between different collagen species. There was an association between the presence of anti-native Type II collagen antibody and the expression of HLA-DR2. It is suggested that the production of anti-collagen antibody may be under genetic control in RA, but not associated with the major genetic marker of disease susceptibility, HLA-DR4.

Controlled trial of hydroxychloroquine and D-penicillamine singly and in combination in the treatment of rheumatoid arthritis.

A 2-year, controlled, double-blind trial of D-penicillamine and hydroxychloroquine either alone or in combination was conducted on patients with progressive rheumatoid arthritis. The group given D-penicillamine alone improved most, but a linear fall-off in efficacy occurred. Surprisingly, the group receiving combination drug therapy did not fare as well as the group receiving D-penicillamine therapy. A subset of patients receiving hydroxychloroquine therapy had prolonged benefit. Toxicity, though not uncommon, was generally not severe.

Systemic lupus erythematosus developing in patients with primary biliary cirrhosis.

Three patients with biopsy-proven primary biliary cirrhosis subsequently developed a multisystem disorder and serologic abnormalities consistent with systemic lupus erythematosus. In one patient, antimitochondrial antibody titers fell to undetectable levels after the development of the extrahepatic manifestations. No patient had been exposed to D-penicillamine or other drugs capable of inducing a lupus-like condition. These patients further emphasize the difficulties in disease classification and underline the systemic nature of chronic liver diseases such as primary biliary cirrhosis.

Renal tubular acidosis. A new look at treatment of musculoskeletal and renal disease.

The clinical and laboratory manifestations, roentgenographic findings, and treatment of 48 patients with renal tubular acidosis who were examined at the Mayo Clinic during a 10-year period were reviewed. The initial clinical presentations of the 48 patients in the series included rheumatic complaints in 25 and recurrent nephrolithiasis in 23. Of the 23 patients who presented with nephrolithiasis, 8 also had musculoskeletal symptoms. Thirty-three of the 48 patients had careful follow-up of a total of 68 musculoskeletal complaints. Forty of these symptoms (59%) diminished after treatment of the renal tubular acidosis with orally administered alkali. Associated connective tissue diseases were present in 12 patients. Thirty-four patients had roentgenographic evidence of renal calculi. Of this group, 19 were followed up with sequential roentgenographic studies of the kidneys for more than 1 year during therapy. Of 15 patients treated orally with alkali, 13 had metabolically inactive renal stone disease. Three of the patients treated orally with phosphorus supplements had persistent metabolically active renal stone disease. Patients with renal tubular acidosis often present with musculoskeletal manifestations and renal lithiasis, both of which frequently subside with the treatment of the renal tubular acidosis.

Comparison of clinical and serologic markers in systemic lupus erythematosus and overlap syndrome: a review of 247 patients.

To evaluate the relationship between clinical manifestations and serologic markers in patients with systemic lupus erythematosus (SLE) and patients with an overlap syndrome, we reviewed the charts of 247 such patients who had been examined between 1975 and 1979. All patients with an overlap syndrome had a high frequency of arthritis and Raynaud's phenomenon and a low frequency of renal disease regardless of the presence or absence of antibody to nuclear ribonucleoprotein (anti-nRNP) and antibody to Sm antigen (anti-Sm). The presence or absence of anti-nRNP and anti-Sm did not distinguish whether a patient had SLE or an overlap syndrome and could not be used to predict clinical manifestations of disease.

Treatment of renal lithiasis associated with renal tubular acidosis.

In order to determine the incidence of renal lithiasis in patients with renal tubular acidosis and the effect of therapy on further stone formation, we reviewed the clinical and laboratory manifestations, X-ray findings, and treatment of 48 patients with renal tubular acidosis who were seen at the Mayo Clinic during the years 1970-1980. Thirty-four patients (70%) had radiological evidence of renal lithiasis which was the presenting symptom in 23 (48%) patients. In every instance the calculi were multiple and, with one exception, bilateral. While receiving therapy, 19 patients with renal lithiasis were followed for longer than one year with sequential uroradiographic studies. Fifteen of these patients were treated with oral base alone and thirteen had no evidence of new stone formation or continued growth of existing stones during therapy. The two patients with X-ray evidence of continued stone formation admitted to poor compliance. Four patients received initial treatment with an oral phosphorus supplement. Three of these four patients had radiographic evidence of continued renal stone formation during three, five and eight years of phosphate therapy. We conclude renal lithiasis is a frequent complication of renal tubular acidosis, and adequate base replacement is effective therapy to stop continued stone formation while oral phosphate therapy alone is often ineffective.

Pulmonary hypertension in polymyositis.

Pulmonary hypertension is an uncommon but lethal complication of polymyositis. A 69-year-old woman is described who had a 20-month history of polymyositis and cardiac failure and in whom severe pulmonary hypertension was noted terminally when she was first seen at our clinic. She died within 24 hours of admission, and autopsy revealed severe plexogenic pulmonary vascular disease.

Prednisone and azathioprine for polymyositis: long-term followup.

Two groups of patients with polymyositis have been followed for approximately 3 years. One group was treated with prednisone alone and the other with prednisone plus azathioprine. Although the polymyositis of both groups has improved, no statistically significant difference was noted at the end of 3 months, as previously reported. Longer followup, however, has shown that the group given prednisone plus azathioprine has improved more with respect to functional disability; this group also requires less prednisone for disease control.