No abstract

Four children, 7 to 24 months old, were found to have anti-M at the time of admission to the hospital for severe acute bacterial infections. All were M-N+. Two patients had meningitis, one had septic arthritis, and the fourth had a third-degree burn of the left hand. In follow-up studies the anti-M of patients No3 and No4 were no longer detectable after 12 and 11 months respectively. In all patients no demonstrable antibody was in either maternal or cord sera at time of birth. The clinical data and bacterial isolations lead us to postulate that bacterial infections account for the formation of naturally occurring anti-M in M-negative persons.

Experiments were performed to compare the formation of microaggregates in stored human whole blood (WB) with that in stored packed cells (PC) and also to compare the effectiveness of standard blood transfusion filters with dacron wool (Swank) micropore transfusion filters in removing such microaggregates. After 5, 10, 15 and 20 days of storage SFP and debris weights of PC's were considerably greater than those of matched WB samples. Passage of either WB or PC's through standard blood transfusion filters resulted in small decreases in SFP and debris weights. Passage of either WB or PC's through dacron wool (Swank) transfusion filters led to striking and highly significant decreases in both SFP and debris weights. When stored PC's were diluted to the same hematocrits as their corresponding WB samples, SFP remained considerably elevated above those of the WB samples. On the basis of this research, it is concluded that centrifugation of blood during component separation leads to a significant increase in microaggregate formation over and above that which progressively occurs during storage and that the risk of pulmonary microembolization during transfusion with stored PC's is greater than that during WB transfusion. For this reason, dacron wool (Swank) filters should always be used when PC's are being transfused.