C WILKINSON1,2, G KAN1,2, V MANICKAM1,2, V SRIVASTAVA1,2
1The Townsville Hospital, Queensland; 2James Cook University Clinical School, Queensland
Background: There were 37 notifications for active tuberculosis (TB) infection in Australian haemodialysis patients between 2001 and 2006. The incidence of TB in Australia is 5-7 per 100 000 and 4.5 per 100 000 in Indigenous Australians.
Case report: A 61 year old Indigenous male was noted to be hypercalcaemic in February 2017 on routine biochemistry. His background was of ESKD secondary to diabetic nephropathy, commenced on haemodialysis via right brachio-basilic fistula in 2014. There was no oral calcium or vitamin D supplementation. There was history of distant contact with TB. Investigations into hypercalcaemia included CT body, with no initial abnormality; negative myeloma screen, angiotensin converting enzyme within normal limits, and negative tumour markers including prostate specific antigen. Hormonal studies showed suppressed parathyroid hormone, elevated 1,25-dihydroxyvitamin D and suppressed 25-hydroxyvitamin D, suggestive of granulomatous disease. Hypercalcaemia was managed with low calcium dialysate, pamidronate, calcitonin and denosumab however persisted. A new scrotal ulcer was noted in April 2017; and repeat imaging (CT and PET) revealed diffuse abdominal and inguinal disease with omental caking, ascites and lymphadenopathy. Initial swab of the scrotal lesion were negative for acid fast bacilli (AFB) but became culture positive for Mycobacterium tuberculosis on day 20; core biopsy of left inguinal node showed necrosis and bacteria without granuloma or malignancy. A regime of rifampicin, isoniazid, pyrazinamide and ethambutol was commenced. Initial medical management of hypercalcaemia was ineffective and dialysis was required to reduce serum calcium; prednisolone was added to the anti-TB regime for further control of hypercalcaemia.
Conclusion: TB can be challenging to diagnose in haemodialysis patients as it is more likely to present as extra-pulmonary disease and rarely presents with classic symptoms.