Rhabdomyolysis associated with pulmonary tuberculosis.

To the Editor: Rhabdomyolysis, a syndrome of muscle breakdown, is caused by a variety of infectious and noninfectious etiologies. To my knowledge, this is the first reported case of rhabdomyolysis caused by active pulmonary tuberculosis.

A 60-year-old African-American gentleman presented to the emergency room with productive cough associated with fever, weight loss and occasional night sweats.

The patient denied muscle weakness or tenderness. He also denied a recent history of trauma or falls. The patient is known to be diabetic. He was taking only multivitamins and had no history of illicit drug abuse. The physical examination revealed diminished breath sounds over the right lower and upper lobe segments on auscultation and dullness over the right lung on percussion. The rest of the examination was unremarkable.

Laboratory studies revealed a serum glucose level of 280 mg/dL, a blood urea nitrogen level of 8 mg/dL, a creatinine level of 0.7 mg/dL, a sodium level of 130 mmol/L, a potassium level of 3.2 mmol/L, a phosphorus level of 2.6 mg/dL, a magnesium level of 1.7 mg/dL, and a calcium level of 1.22 mg/dL. The creatine kinase (CK) level was 13,918 IU/L at admission and increased to above 16,000 IU/L the following day. Creatine kinase myocardial band, thyroid stimulating hormone, and liver function tests were normal. A computed tomography (CT) scan of the chest revealed a complete opacification of the right upper lobe with central cavitation. A sputum acid-fast stain showed abundant acid-fast bacilli and the culture grew Mycobacterium tuberculosis. The patient was treated with IV fluid and antituberculous drugs. The patient's creatine kinase level started declining after one week of therapy and the patient was later discharged home on an oral antituberculous drug regimen.

Rhabdomyolysis is a life threatening disease resulting from the disintegration of skeletal muscle cells. The causes are generally secondary to trauma, exertion, drugs, toxins, electrolyte abnormalities, endocrine disorders, inflammatory myopathies and infections. Active pulmonary tuberculosis has not been reported yet as a cause. Review of the literature revealed only one case by Cases et al reporting rhabdomyolysis associated with pleural tuberculosis. (1) This case did not involve pulmonary tuberculosis. Other reported cases of pulmonary infections associated with rhabdomyolysis have generally been related to viral or bacterial etiologies such as influenza, chlamydia, Legionella, mycoplasma, streptococcus and staphylococcus. The pathophysiologic mechanism in these infections leading to rhabdomyolysis is presumed to be muscle injury from direct toxin effect, hemodynamic alterations, immune-mediated process, or direct invasion. (2-4)

Samer Zeayter, MD

From the Department of Internal Medicine

Danbury Hospital

Danbury, CT

References

1. Cases A, Grau J, Latorre X, Moreno A. Rhabdomyolysis associated with pleural tuberculosis. Arch Intern Med 1986;146:2411.

2. Posner MR, Caudill MA, Brass R, Ellis E. Legionnaires' disease associated with rhabdomyolysis and myoglobinuria. Arch Intern Med 1980;140:848-850.

3. Hroncich ME, Rudinger AN. Rhabdomyolysis with pneumococcal pneumonia: a report of two cases. Am J Med 1989;86:467-468.

4. Lannigan R, Austin TW, Vestrup J. Myositis and rhabdomyolysis due to Staphylococcus aureus septicemia. J Infect Dis 1984;150:784.