“…Low or moderate azotemia (urea 70 mg%) does not hamper diphtheria antitoxin production [42], With advanced renal insufficiency, however, very low agglutination titers are found after typhoid immunization. Acute skin reactions against several natural antigens (pollen, Candida) are also sup pressed [25], Skin reactions after passive immunization and after subcutane ous histamine injection, on the other hand, remain unchanged [44], These skin reactions are not useful for individual testing, because signifi cant differences are only found when comparing large groups.…”