[Diagnosis of pulmonary tuberculosis using Ziehl-Neelsen stain and polymerase chain reaction]

Definitive diagnosis of unclear pulmonary lesions is mainly based on morphological methods. In addition to a neoplasm, inflammatory reactions, in particular tuberculosis (TB), have to be considered in most cases. Therefore, the aim of this work was to determine whether established methods used in general pathology can be efficiently used with cytological material.

An established polymerase chain reaction (PCR) protocol for the detection of Mycobacterium tuberculosis complex (Mtc) DNA in fixed specimens was conducted on fixed material available as an assay for liquid-based cytology (LBC). CytoLyt®-fixed material of 45 patients with clinically suspected TB or other mycobacteriosis were selected and were initially tested cytologically. In cases of absent tumor cells, PCR for detection of Mtc DNA and Ziehl-Neelsen stain (ZN) were performed.

In 9 patients (20 %), Mtc DNA was found by PCR. The following methods were used to obtain material: catheter biopsy (5), needle biopsy (2), transbronchial needle aspiration (1), and bronchoalveolar lavage (1). Cytologically an inflammatory reaction was observed in all cases. In 2 patients, a history of TB, in 2 further cases either silicosis or a posttransplant situation was known. In cases with a positive PCR, 7 patients (78 %) were positive in ZN and 3 patients (33.3 %) in TB culture (15.5 % vs. 6.7 % of the total cohort); however, the material used for investigation was not always from identical sources, respectively. In 36 out of 45 patients, both PCR and ZN were negative for the detection of Mtc DNA.

The material intended for LBC can be used for detection of TB with ZN and Mtc PCR.