1 Department of Nephrology, 2 Department of Pathology, Sanjay Gandhi Post Graduate Institute of Medical Sciences, Lucknow, India
Sir,
Amongst mycobacterial infections, tuberculosis is the most frequent in renal transplant recipients. Leprosy, although widespread in some tropical countries including India, is uncommon in renal transplant recipients. Co-infection with leprosy and tuberculosis has been reported in the general population [1]. We report a case of a renal transplant recipient with pulmonary tuberculosis occurring concomitantly with leprosy. To best of our knowledge this is the first case of co-infection with tuberculosis and leprosy reported in a renal transplant patient.
Case.
A 40-year-old male patient with chronic renal failure due to presumed chronic glomerulonephritis received a live related renal transplant in September 1990. The patient had no history of tuberculosis or leprosy prior to transplant. Post-transplantation, the patient was put on triple drug immunosuppressive therapy, including prednisolone, azathiorpine and cyclosporin. He had an episode of acute rejection about 1 month post-transplant that was successfully treated with methyl prednisolone. Cyclosporin was withdrawn 1 year after transplantation and the patient's graft function is well maintained on azathioprine 2.5 mg/kg/day and prednisolone 10 mg/day.
In February 1998 the patient was admitted for evaluation of prolonged fever of 1 month duration. He also complained of a productive cough of similar duration. Clinical evaluation was largely unremarkable. Urinalysis, full blood count, urea and electrolytes and chest X-ray were within normal limits. Sputum examination revealed acid-fast bacilli by ZiehlNelson staining. Later, sputum culture also demonstrated growth of acid-fast bacilli, and based on culture characteristics like slow growth, rough and buff coloured colonies and absence of pigment in dark or on exposure to light the organism was identified as Mycobacterium tuberculosis. Anti-tubercular therapy was instituted with four drugs that included isoniazid, rifampicin, ethambutol and pyrazinamide. Over the following 23 weeks the patient became afebrile and had marked symptomatic improvement. Meanwhile a hypoesthetic and hypopigmented patch was detected over the right forearm, and on examination the ipsilateral ulnar nerve was found to be thickened and tender. The patient admitted that the patch had been there for 2 months. A biopsy of dorsal ulnar nerve was performed. It stained positive for Mycobacterium leprae and a lepromatous type of leprosy was reported. Two anti-leprosy drugs including dapsone (100 mg/day) and clofazimine (100 mg/day) were started in addition to anti-tubercular treatment. Two months later the patient developed an erythematous rash with low grade fever suggesting lepra reaction which responded to a short-term (2 weeks) increase in prednisolone dosage. A repeat sputum examination after 3 months was negative for acid-fast bacilli. Anti-tubercular treatment was stopped after completing 12 months of therapy. However, the patient is still receiving rifampicin at a dose of 600 mg once a month as part of anti-leprosy treatment in addition to daily dapsone and clofazimine. We intend to treat leprosy for a longer period (1.5 years completed) since the patient is immunosuppressed. During this period graft functions remained stable.
Comment.
Mycobacterial infections, predominantly tuberculosis, are commonly seen in renal allograft recipients in our country. These infections require long-term therapy with relatively toxic drugs, and are responsible for a significant amount of morbidity and mortality. The incidence of tuberculosis is much higher in our population of renal transplant recipients. Sakhuja et al. have reported an incidence of 11.8% from India [2] as compared to only 0.8% as reported from the USA and Spain [3,4].
The exact incidence of leprosy is not known. Date and colleagues reported five cases occurring from 22 months to 12 years post-transplant in their study [5].
In the present case the patient had co-infection with leprosy and tuberculosis that were diagnosed at about the same time. Leprosy in this case was detected by incidental finding of a hypoesthetic and hypopigmented patch. The patient did not complain of this problem. Therefore a high index of suspicion is needed to pick up these lesions at an early stage before the disease is widespread, when it would be much more difficult to treat. The patient was treated simultaneously for both mycobacterial infections and responded favourably.
References