Qualitative and quantitative changes of bone marrow cells in sensitized rabbits

Bone marrow of adult rabbits was dynamically investigated during the sensitization of animals with the complete Freund's adjuvant containing 10 per cent human gammaglobulins (five intramuscular injections of 1 ml adjuvant, one per week). Smears, imprints and paraffin sections from tibial and femoral bone marrow were examined in normal, unsensitized animals, and a week after the third, the fourth and the fifth antigenic stimulations. The differential count of about 10,000 elements of 20-25 smears and imprints allowed the establishment of normal and modified myelograms at each sacrificing term. A high increase in the number of monocytes, small lymphocytes and plasma cells was noticed after the third antigenic stimulation, with statistically significant values as compared to controls. The increase in the number of lymphocytes--including both T and B cells--was more marked after the 3rd antigenic stimulation, later on the proportional increase diminished, the proliferation maintaining itself "en plateau". The ratio between myeloblastic-myelocytic and erythroblastic-erythrocytic elements doubled after the third antigenic stimulation and increased up to six times after the fifth one, due to an absolute decrease of the erythroblastic-erythrocytic line.