Effectiveness of Anti Tuberculous Treatment in patients with Chronic Kidney Disease

Background: Tuberculosis(TB) is the most common infectious cause of mortality across the world. Chronic Kidney Disease (CKD) is an acquired immunosuppressed state associated with increased risk of infections, especially Tuberculosis.The effectiveness of Anti Tuberculous Treatment (ATT) in CKD patients with TB has not been studied previously. There are no guidelines put forth in treating TB in patients with CKD.

Objective: To study the profile of TB, the effectiveness of ATT and ATT induced complications in CKD patients.

Methods: It was a prospective study from August 2008 to July 2010.All CKD patients with a diagnosis of TB were included. They were started on ATT using Isoniazid(5mg/kg), Rifampicin(10mg/kg),Pyrazinamide (12-20mg/kg),Ethambutol (15-25mg/kg) and/or Ofloxacin 400mg.INH and Rifampicin were given daily whereas Pyrazinamide and Ethambutol/Ofloxacin was given on alternate days. Doses were adjusted according to GFR (Creatinine Clearance).Patients with severe forms of TB(CNS,Spine,Pericarditis and Disseminated)were treated for 1year where as patients with less severe forms(Pleural effusion,Lymphadenopathy,Ascites and Abscess) for 6 months to 1year.The patient was declared cured if there was clinical improvement with radiological,microbiological or laboratory evidence of improvement.Exclusion criteria included patients aged less than 13years,HIV infected,patients with underlying liver disease and post renal transplant patients.

Results: 33 patients with CKD had Tuberculosis.The incidence of Tuberculosis was 5.77%, much higher than incidence in general population.Mean age of patients was 46.4± 17 years and male to female ratio was 3:1. Extra pulmonary TB was the predominant form(84.8%), of which TB pleural effusion(32.1%) was the commonest followed by CNS TB(17.9%).The other forms of TB seen in our study were Genitourinary,Lymphadenopathy,Ascites,Spinal,Abscess,Disseminated and Pericardial effusion.A cure rate of 84.8% was noted in these patients.The most common ATT induced complication was gastritis(36.1%) followed by drug induced hepatitis(11.1%) .The other complications noted were rash(5.6%)and INH psychosis(2.8%). Worsening of renal function was seen only in 2.8%.Mortality of TB in CKD was 9.09%.Mortality was maximum in Disseminated TB,followed by CNS TB.

Conclusions: This study highlights the high incidence of Tuberculosis, especially Extra pulmonary TB,in patients wilth CKD. Response to ATT was seen in 84.8%,althought it is not as robust as seen in patients with normal GFR. Gastritis was the commonest complication,followed by drug induced hepatitis.Worsening of renal function was seen only in a few, establishing the fact that ATT is safe, if adjusted for GFR,in CKD patients.