Allergic hypersensitivity to the lentil pest Bruchus lentis

Lentils are the most common legume involved in allergic reactions in the Mediterranean area and India. Lentil crops could be attacked by a wide range of insect species. Occupational asthma caused by the lentil pest Bruchus lentis has been described in the present study.

We studied the possibility of immunoglobulin (Ig)E-mediated hypersensitivity to lentil pests in 16 patients who suffered from allergic symptoms (asthma and anaphylaxis) related to inhalation of lentil particles or ingestion of lentils, in which sensitization to legume proteins was not clear.

Extracts prepared either from noninfested and infested lentils, and from the lentil parasite B. lentis were used for skin prick testing (SPT), bronchial and oral challenges and in vitro determinations.

Skin prick test were positive to infested lentils and B. lentis in all patients and negative to noninfested lentil extracts. Five asthmatic patients reacted in the bronchial challenge test with Bruchus extract. Oral challenges performed with boiled infested lentils were positive in six of seven patients. Immunoglobulin E immunoblotting with Bruchus and infested lentils extracts revealed protein bands that were reactive to serum IgE from six and four, respectively, out of 16 patients. These patients had no IgE to lentil-specific proteins as determined by immunoblotting and Len c 1-specific IgE test.

Lentil pest proteins can be a cause of IgE-mediated rhinoconjunctivitis and asthma in patients eating or inhaling infested lentil particles.