Udo Reischl

Institute of Medical Microbiology and Hygiene, University of Regensburg, Franz-Josef-Strauß-Allee 11, 93053 Regensburg, Germany

Received 06/18/96; Accepted 07/19/96; On-line 08/01/96

The basis for effective treatment and cure of a patient is the rapid diagnosis of the disease and its causative agent, which is founded on the analysis of the clinical symptoms coupled with laboratory tests. As we approach the 21st century, clinicians are becoming increasingly able to diagnose and treat diseases at the molecular level. The rapid development of new methods and techniques in the area of molecular biology has gained new insights into the genetic and structural features of a considerable number of human pathogens. These results obtained by intensive basic research are currently leading to improved diagnostic procedures.

Basically, there are four different possibilities for laboratory diagnosis of infections: 1. direct detection of the pathogens (e.g., microscopy and/or culture), 2. detection of protein components of the pathogens with the help of specific antibodies (e.g., antigen capture ELISA) 3. IgA-, IgM- and IgG-specific detection of antibodies directed against a given pathogen and changes in their corresponding titer, and as the most sensitive method, 4. specific detection of nucleic acids (e.g., PCR) of the pathogens.

Here, the human immunodeficiency virus (HIV) and Mycobacterium tuberculosis are serving as examples to review the recent developments as well as the future perspectives in molecular biology-based laboratory diagnosis (Figure 1).

Figure 1: Modern laboratory diagnosis of infections is mainly based on refined traditional methods like microscopy and culture, specific detection by antibodies and, more recently, on the specific and high-sensitive detection methods for detection of nucleic acids.