Use and abuse of eight widely-used diagnostic procedures in clinical immunology: a WHO Memorandum.

This Memorandum assesses eight widely-used diagnostic procedures with the aim of establishing their usefulness in patient care. For each procedure, the main methods that can be recommended at present are outlined and their pitfalls discussed. For each procedure, recommendations are made as to the clinical conditions for which the test is essential for diagnosis, the conditions for which the test will help in assessing and monitoring disease activity, and the conditions for which the test is useful for research purposes only.