Bronchoalveolar lavage (BAL) is one of important diagnostic and therapeutic procedures in pneumonology. It’s also one of very few procedures enabling determination of biochemical and immunological processes of the lung tissue. BAL is usually performed during routine bronchofiberoscopy. Both cellular and humoral elements are estimated in the material obtained during BAL. However, due to very low concentrations of most investigated substances in BAL fluid (BALf), it has to be concentrated prior to further analysis for which standard methods (in accordance with manufacturer’s protocols) are employed: ELISA (enzyme linked immunoassay), RIA (radio-immunoassay) as well as radioimmunodyfusion. One of the most important limitations of BALf results interpretation is lack of its standardization. This compromises comparing results from different laboratories as well as following dynamics of concentrations and/or activities of BALf components.

In the paper authors present briefly indications for diagnostic use of BALf. They also stress the most common mistakes in BAL technique resulting in misleading results. Based on their experience authors discuss effective measures to avoid or diminish the risk of false results. Amongst others: the use of standardized volume of instilled liquid, appropriate placing of the bronchoscope ending in the segmental bronchus, separate aspiration and analysis of the first aliquot of aspired BALf, appropriate handling of the samples – including early spinning down of cellular elements and deep-freezing of supernatants. In summary authors conclude that BALf analysis is already today a valuable source of immunological information, however further research leading to a better standardization of BAL procedure is needed to make such an analysis a fully reliable diagnostic tool.