RAST using crude and purified anti-IgE

Drug allergy diagnosis in humans: possibilities and pitfalls

Due to the potential hazards of drug allergies, an early and reliable diagnosis is crucial. The use of in vivo tests is not recent but, because of the hazards of skin testing in patients with a history of anaphylaxis, they had been abandoned for a while. Recent reevaluations have shown that for some drugs, e.g. antibiotics-reliable skin tests can ensure the diagnosis of drug allergy in up to 70% of cases. Many in vitro tests based on well-defined mechanisms, e.g. the basophil degranulation test have been used for the diagnosis of totally unrelated allergic mechanisms. It is almost impossible to interpret their validity as diagnosis tools. Nevertheless, other tests, e.g. the lymphocyte transformation test which have been evaluated in well-conducted recent studies, seem to have a good predictive value. Their use is still restricted to clinical trials or research studies. A reliable clinical approach as well as a detailed examination of the drug intake remains obligatory to diagnose drug allergy. Available in vivo and in vitro tests are sometimes used to confirm the diagnosis. The sensitivity and specificity of these tests is evaluated in clinical studies. Research to improve the existing tests and to develop new diagnostic tools is still of paramount importance.

Specific IgG subclass antibodies, IgE and IgG S-TS antibodies to wheat gluten fraction B in patients with coeliac disease

Antibodies were measured in the sera of fifteen patients with untreated coeliac disease and twenty-eight patients with inflammatory bowel disease. Increased levels of specific IgG, IgG1, IgG2, and IgG4 antibody to wheat gluten fraction B, measured by an enzyme-linked immunosorbent assay, were shown in the coeliac disease group, but not in the inflammatory bowel disease group. No specific IgE antibody to fraction B was detected but 33% of the patients with coeliac disease had specific short-term sensitizing (anaphylactic) IgG antibody activity (IgG S-TS) to fraction B. There was no correlation between the IgG2 or IgG4 specific antibody and the presence of IgG S-TS activity.

IgE antibody levels to ingested soya protein determined in a normal adult population

Levels of soy protein-specific IgE were measured in a normal adult population (seventy-four males, and fifteen females) who ingested soya-containing and control diets during two 4-week periods. Increases in soya-specific IgE were observed for some individuals following ingestion of the soya-containing diet, and for the female group the increase in soya-specific IgE was statistically significant (P = 0.02). The increase of soya-specific IgE was small and led to lower levels than that associated with adverse effects. The increase in soya-specific IgE in the female group was accompanied by a significant increase (P = 0.02) in total immunoglobulin A. Changes in the level of soy-specific haemagglutinating antibody, soya-specific IgG, IgA and IgM as measured by ELISA and the immunoconglutinin titre could not be related to ingestion of the soya-containing diet.