Tuberculosis Therapy Effective in CKD Patients
Teny Mathew John, MD
SAN DIEGO—Anti-tuberculosis treatment (ATT) appears to be both safe and effective in patients with chronic kidney disease (CKD), data show.
In a 12-month study of 572 CKD patients, of whom 33 had tuberculosis (TB), researchers in India found that 84.8% of subjects responded to ATT, although the responses to the treatment were not as robust as seen in patients with normal kidney function. Clinicians may need to modify the dosing interval of ATT for patients with impaired kidney function, who may not achieve optimal outcomes with standard daily therapy.
The study also showed that gastritis was the most common complication from ATT in CKD patients, followed by drug-induced hepatitis. The investigators observed worsening of renal function in a minority of CKD patients.
“TB is endemic in the developing world and India has the second largest burden of disease,” said lead investigator Teny Mathew John, MD, currently a specialist in infectious diseases at Hamad General Hospital Doha Qatar. “Chronic kidney disease is an immunosuppressed state like HIV. We had many patients with CKD presenting with unexplained fever and weight loss and when evaluated had radiological, biochemical, or microbiological evidence of TB. Some had response to empirical anti TB treatment as well.”
Dr. John presented study findings at IDWeek, a conference sponsored by the Infectious Diseases Society of America and three other medical organizations.
TB management in CKD patients is not well defined and guidelines stop short of formulating a proper treatment plan. He and his colleagues analyzed the effectiveness of ATT overall in CKD patients as well as the effectiveness of specific dosing and duration of ATT.
The prospective study, which included 33 CKD patients with TB, was conducted from August 2009 to July 2010 at the Department of Nephrology/Medicine, Government Medical College, Kottayam, Kerala, India, under the guidance of K.P.Jayakumar, MD, Professor and Head of Nephrology. All CKD patients with a diagnosis of TB were included and each patient was started on ATT using isoniazid (5mg/kg), rifampicin (10mg/kg), pyrazinamide (12-20 mg/kg), ethambutol (15-25mg/kg) and/or ofloxacin 400 mg. Patients were given isoniazid and rifampicin daily and given pyrazinamide and ethambutol/ofloxacin on alternate days (thrice weekly).
Patients with severe forms of TB (central nervous system [CNS], spine, pericarditis, and disseminated) were treated longer than those with less serve forms (pleural effusion, lymphadenopathy, ascites, and abscess). Patients were excluded from the study if they were under the age of 13, were HIV infected, if they had underlying liver disease, or were renal transplant recipients.
Extra pulmonary TB was the predominant form diagnosed (84.8%) and among these patients TB pleural effusion (32.1%) was the most common followed by CNS TB (17.9%). Of the 33 TB patients, 28 (84.8%) were cured, meaning they had radiological, microbiological, or laboratory evidence of improvement.
“TB should be one of the important differential diagnoses in a CKD patient with unexplained fever and weight loss,” Dr. John told Renal & Urology News. “Genitourinary TB in CKD can present as strictures and scarring and usually the radiological findings are quite specific. The outcome of TB treatment is comparable to that of the general population although the treatment duration is prolonged, needing up to one year.”
The most common ATT-related adverse event (AE) was gastritis (36.1%), followed by drug induced hepatitis (11.1%). Other notable AEs included rash (5.6%) and isoniazid-induced psychosis (2.8%). A worsening of renal function was observed only in 2.8%. The study cohort had a 9% mortality rate. The rate was highest among those with disseminated TB and CNS TB.