Side Effects during Immunotherapy with Purified Grass Pollen Extracts

Abstract

In a 3-yr prospective double blind study, grass pollen allergic patients were allocated to perennial hyposensitization with the timothy major allergens No. 19 and 25 (2-component extract) or a 20-component timothy extract. The extracts were biologically standardized and adsorbed to Al(OH)3 for treatment. Systemic side effects (SSE) had debut after 1.05-5 h and lasted without treatment 0.05-10 h. Treatment with the 2-component extract showed preponderance of minor SSE (arthralgia, rhinitis, tiredness, headache, conjunctivitis, nausea, flu-like symptoms), but major SSE (urticaria, angioedema, asthma) were equally distributed between treatment with the 2 timothy extracts. Major SSE complicated the treatment before the first grass pollen season in 33% of the patients vs. only in 3% during the subsequent perrenial therapy, and developed (92%) at high single dose of .gtoreq. 1,000 biological units. The majority (69%) were later able to reach the same or higher dose withut relapse. Most (62%) patients with major SSE were predicted by high nasal sensitivity before treatment. Only 18% of the patients had immediate local skin reactions of .gtoreq. 2 cm, but delayed local side effects of .gtoreq. 10 cm were recorded in 70%. Immediate skin reactions did not correlate with delayed skin reactions or with SSE, but delayed local side effects tended towards negative correlation with major SSE. A mean area reduction of 50% of the delayed skin reactions was recorded by repetition of a single dose. Subcutaneous nodules appeared at single doses of .gtoreq. 5,000 biological units. Only 5% of the patients contracted nodules during initial preseasonal therapy compared with 38% during subsequent perennial dosage. The nodules contained typical benign granulomas, and the frequency in the 2 groups was proportionate to the quantity of Al in the 2 extracts.