Comment on "chyluria: a mimicker of nephrotic syndrome".

To the Editor: With reference to the interesting paper by Kaul et al,1 tuberculosis (TB) is one of the important non-parasitic causes of chyluria. TB is a common health threat in India with a prevalence of 545 per 100 000 and ranged from 201 in the highest quintile to 1100 in the lowest quintile.2 Kaul et al1 stated in their study that urine test for acidfast bacilli (AFB) in all the studied patents was negative. However, they did not address the applied laboratory test(s) to fill that objective. This is critical as there is a substantial variation in the detection rate of AFB depending on the applied laboratory test. For instance, the detection rate of AFB in urine specimen in patients with suspected renal TB by bacterioscopy (56.25%) is less than that detected by polymerase chain reaction (PCR) method (81.25%).3 Also, the detection of M tuberculosis DNA in renal biopsy tissue by real-time PCR is proved to be highly sensitive as it can increase diagnostic accuracy and provide valuable information regarding the early diagnosis of renal TB.4 Therefore, the over-reliance by Kaul et al1 on negative urine test for AFB to totally exclude TB in all their studied patients with chyluria is questionable.