Introduction Patients with chonic kidney disease (CKD) are at increased risk of developing tuberculosis (TB) due to immunosuppression from renal failure. There is little information on incidence of TB in CKD patients in countries such as the UK with a low background rate of TB. The incidence of TB is 14.9/100 000 population in UK and 43/100 000 population in London.1 Our aim was to establish this incidence in our CKD patients.
Methods We identified 40 patients with CKD at a single large renal unit in London who developed TB from 1994 to 2010. Data collected included site of TB, treatment received for CKD (pre-dialysis, peritoneal dialysis (PD), haemodialysis or transplant) and outcome. Incidence of TB was calculated from total number of TB patients and total number of CKD patients in each CKD treatment group from 1994–2010.
Results Sites of TB were: 21 pulmonary, six lymph node (cervical, mediastinal and aortic lymph nodes), five disseminated/miliary, six spinal, one renal, one skin and three of unknown sites. Only three patients had a past medical history of TB. Three PD patients had TB of whom two had peritoneal TB. 18/40 CKD/TB patients were pre-dialysis, 3/40 had PD, 15/40 were on haemodialysis, 4/40 had a transplant. The incidence of TB was 398/100 000 in patients on PD, 1267/100 000 in patients on haemodialysis and 298/100 000 in renal transplant recipients. No total pre-dialysis patient numbers were available. 17/40 patients were further immunosuppressed by either HIV (five cases) or drugs (12 patients) such as prednisolone, cyclosporine, tacrolimus or mycophenolate mofetil. Most of the latter had either functioning or non-functioning transplants. All patients were cured except for one who died of an unrelated cause.
Conclusions Patients with CKD are at increased risk of developing TB compared with the general UK population. Peritoneal TB is more common in patients on PD whereas pulmonary TB is seen more often in other CKD groups followed by lymph node TB. More than two fifth of the CKD/TB patients had further immunosuppression in the form of drugs or HIV infection, thus further increasing their risk of developing TB.