PREDICTIVE VALUE OF INVITRO TESTS FOR THE IGE-DEPENDENT AND THE IGE-INDEPENDENT ANAPHYLACTOID REACTIONS TO MUSCLE-RELAXANTS

Several aspects of in vitro tests for life-threatening anaphylactoid r eactions (AR) to neuromuscular blockers (NMB, muscle relaxants) were a ddressed and highlighted. They include topics which have been under st udy in our centre in the past few years. Already available tests and n ewly developed ones were assessed for diagnostic and predictive value, as well as for usefulness in understanding of mechanism(s) of AR. The theoretical and practical aspects of radioallergosorbent tests (RAST) for antibodies to NMB (particularly IgE), their predictive value and their possible use in << screening >> with the hope of preventing AR a re discussed, Confirmatory tests after AR include plasma or serum hist amine/methylhistamine, tryptase and possibly eosinophil cationic prote in (ECP), all of which point to activation of mast cells, basophils, e osinophils and possibly other inflammatory cells. Future anaesthetics after AR can be guided by measurement of the in vitro release of hista mine, leukotrienes and possibly eosinophil cationic protein (ECP) and serum antibodies. Antibody studies (mainly IgE by RAST) are valuable f or diagnosis and, together with other tests, can throw light on cross- reaction and further clarify the mechanisms of AR. In RAST (IgE)-negat ive cases of AR, which may be due to immune or nonimmune mechanisms, m ediator release measurements are particularly useful. Lymphocyte stimu lation tests may also be useful in such cases. RASTs cannot be advocat ed for general preoperative screening, as yet. Further development or selection of potentially << susceptible >> subpopulations may improve the predictive value of these tests.