Urinary lipoarabinomannan in individuals with sputum-negative pulmonary tuberculosis.

BACKGROUND OBJECTIVES: Tuberculosis (TB) is a major global cause of ill health. Sputum microscopy for confirmation of presumptive pulmonary TB (PTB) has a reportedly low sensitivity of 22-43 per cent for single smear and up to 60 per cent under optimal conditions. National TB Elimination Programme in India recommends the use of cartridge-based nucleic acid amplification test (CBNAAT) and culture for microbiological confirmation in presumptive PTB individuals with sputum smear negative test. The use of lateral flow urine lipoarabinomannan (LF-LAM) is usually recommended for the diagnosis of TB in HIV-positive individuals with low CD4 counts or those who are seriously ill. The objective of this study was to detect urinary LAM using cage nanotechnology that does not require a physiologic or immunologic consequence of HIV infection for LAM quantification in human urine in 50 HIV-seronegative sputum smear-negative PTB individuals. METHODS: To study the diagnostic value of urinary LAM in sputum smear negative PTB individuals, a cage based nanotechnology ELISA technique was used for urinary LAM in three different groups of participants. Fifty smears negative PTB clinically diagnosed, 15 smear positive PTB and 15 post TB sequel individuals. Sputum was tested by smear, CBNAAT, and culture along with urine LAM before treatment. The results were interpreted by ROC curve in comparison to the standard tests like CBNAAT and culture. RESULTS: The mean urinary LAM value was 0.84 ng/ml in 37 culture-positive [Mycobacterium tuberculosis (M.tb)] and 0.49 ng/ml in 13 culture-negative (M.tb) smear-negative individuals with PTB, respectively. In 47 smear-negative PTB cases with microbiologically confirmed TB by CBNAAT, the mean urinary LAM was 0.76 ng/ml. The mean urinary LAM in post-TB sequel individuals was 0.47 ng/ml. As per the receiver operating characteristic curve, cut-off value of urinary LAM in individuals with smear-negative PTB microbiologically confirmed by: (i) CBNAAT was 0.695 ng/ml and (ii) culture was 0.615 ng/ml. INTERPRETATION CONCLUSIONS: The findings of this study suggest that individuals with smear-negative PTB and a urinary LAM value of >0.615 ng/ml were most likely to have microbiological confirmed TB while those with a LAM value <0.615 ng/ml >0.478 ng/ml are less likely and those with a value <0.478 ng/ml are unlikely to have microbiological confirmed TB.

Fluorescein Diacetate Vital staining for detecting viability of acid-fast bacilli in sputum of pulmonary tuberculosis patients.

OBJECTIVE: To compare the performance of the Fluorescein diacetate (FDA) vital staining method with Ziehl-Neelsen staining method in detecting the viability of acid-fast bacilli using MGIT culture as "reference standard". METHODS: This was a single centre prospective observational study conducted from October 2015 to November 2016. Microbiologically confirmed ZN-Smear positive (3+) sputum specimens were obtained from 30 pulmonary tuberculosis patients taking anti-tuberculosis treatment at DOTS centre of NITRD, New Delhi. Patients were made available to collect the first baseline sputum sample before commencing treatment, and an early morning sputum sample was collected as per RNTCP guidelines. After starting treatment, sputum specimens were collected weekly in the first month and thereafter twice-weekly until 18th week. All sputum specimens from patients receiving anti-tuberculosis treatment were examined using Ziehl-Neelsen (ZN) smear microscopy, FDA vital staining, and MGIT culture. RESULT: Out of 360 follow up sputum specimens collected from 30 adult microbiologically confirmed ZN- Smear (3+) pulmonary tuberculosis patients, 146 were ZN-positive and 130 FDA-positive. Of 130 FDA-positive sputum samples, mycobacteria tuberculosis (MTB) growth was found in 116 sputum samples, of which 116 sputum specimens were positive for FDA. Additionally, 14 culture-negative specimens were FDA positive. No FDA-negative sputum samples were positive for MGIT culture. Among ZN positive specimens, FDA had 100% sensitivity and 85.3% specificity with an accuracy of 96.58% for the detection of viable mycobacteria. Among ZN negative sputum specimens, FDA had comparatively high specificity (95.7%). Using positive MGIT culture as a reference for viability, negative predictive value (NPV) and positive predictive value (PPV) from FDA vital staining method were found to be 100 and 89% respectively. CONCLUSION: FDA staining is a simple and rapid tool for identifying viable MTB bacilli. Because of its excellent NPV and encouraging specificity, FDA staining is useful to identify patients with non-viable bacilli (FDA negative) among retreatment cases at diagnosis and patients on anti-tuberculosis treatment for both drug-sensitive and drug-resistant tuberculosis for follow up for the response of treatment.

Tetany in an Extensively Drug Resistant Tuberculosis (XDR-TB) Patient Treated with Capreomycin.

Gross electrolytes disturbances including hypokalemia, hypomagnesaemia, and hypocalcaemia have been reported in tuberculosis patients who have been treated with capreomycin.1-3 Capreomycin is recommended in the treatment of M. tuberculosis isolates resistant to kanamycin at baseline in multi drug resistant tuberculosis patients (MDR - TB) and treatment of extensively drug resistant tuberculosis (XDR-TB) under programmatic management of drug resistant tuberculosis (PMDT) in India.4 We report a case of tetany in a extensively drug resistant tuberculosis (XDR-TB) patient treated with capreomycin. She developed hypokalemia after 7 weeks of administration of injection capreomycin intramuscularly daily in dose of 750 mg. Hypokalemia was refractory to intravenous potassium replacement therapy. At 12 weeks during the treatment she developed tetany and hypocalcaemia. Hypomagnesaemia was also associated with hypocalcaemia and hypokalemia. Normal level of serum potassium and calcium were achieved with correction of hypomagnesaemia.

Black brown discoloration and hairy tongue - A rare linezolid side effect.

INTRODUCTION: Linezolid was approved for clinical use for methicillin resistant Staphylococcus aureus and vancomycin-resistant Enterococci. Additionally it is used in the management of drug resistant tuberculosis. It is well-tolerated however bone marrow suppression and neuropathies may occur in patients taking this antibiotic for more than 2 weeks. Black discoloration and black hairy tongue (BHT) due to linezolid is rarely reported. We report two cases of BHT. CASE REPORTS: Two patients of drug resistant pulmonary tuberculosis developed benign hairy tongue with linezolid 600mg per day. In both the cases black colored/hairy tongue was reported within 2-3 weeks of linezolid treatment. Both patients improved after withdrawal of linezolid. Subsequent reintroduction of linezolid with good oral hygiene was well tolerated and both patients completed the treatment of 2 years duration without any recurrence. CONCLUSION: Black discoloration and BHT is a rare but transient adverse reaction with linezolid. Reintroduction of linezolid with good oral hygiene is well tolerated.

Microfilariae in association with other diseases. A report of six cases.

BACKGROUND: Lymphatic filariasis is a major public health problem in tropical countries. Earlier reports have reported microfilariae as an incidental finding in body fluids and fine needle aspiration smears from various sites. CASES: The findings of body fluid cytology and fine needle aspiration smears from six patients with microfilariae in association with other conditions--tubercular pleural effusion/lymphadenitis, pregnancy and non-Hodgkin's lymphoma--are presented. Three patients demonstrated an associated eosinophilic cellular exudate. Adherence of inflammatory cells to microfilariae was seen in two patients. CONCLUSION: Although microfilariae in cytologic smears are considered incidental findings, the association of microfilariae with debilitating conditions suggests that it is an opportunistic infection and needs further study.