Steps were undertaken to reduce platelet concentrate outdating while maintaining the ability to provide them to hospitals as needed. A brief daily information exchange was established with the purpose of determining a platelet concentrate production goal for each weekday. This procedure has resulted in the ability to meet 100 percent of the hospital demand while reducing platelet concentrate outdating from greater than 20 percent to 2.95 percent over a 6-month period. When considering the 4 months when all platelet concentrates had 5-day expiration dates, the outdating rate was 2.57 percent. The significant reduction in outdating brought about by our procedure can result in substantial economic savings for a regional blood supplier.

A total of 3,212 samples of blood from asymptomatic volunteer donors positive for hepatitis B surface antigen (HBsAg) by radioimmunoassay and 860 samples negative for HBsAg were tested for the presence of hepatitis e antigen (HBeAg) and its corresponding antibody (anti-HBe) using a rheophoresis technique. Neither HBeAg nor anti-HBe was detected in any sample negative for HBsAg. Of the HBsAg-positive samples, 237 (7.4%) contained HBeAg and 749 (23.3%) had anti-HBe. HBeAg was significantly (P less than or equal to 0.0005) more likely to be in samples with high titers of HBsAg. Anti-HBe had an equal chance of occurring in samples with low or high titers of HBsAg. Both HBeAg and anti-HBe were found in samples with HBsAg subtypes ad or ay. However, a significant association (P less than or equal to 0.0005) between HBsAg/ay and HBeAg as well as an association between anti-HBe and HBsAg/ad was found.

A simple, inexpensive procedure for the isolation and purification of HB8Ag from plasma is described. The technique included precipitation of HBsAg with PEG and elimination of normal plasma proteins by digestion with pepsin. Tween 80 was used to remove contaminating lipoprotein(s). This technique resulted in about a 200-fold gain in the specific activity of HBsAg and yielded about 20-40% recovery. Rabbits immunized with the purified antigen produced type-specific antibodies to HBsAg without detectable reactivity to normal human plasma antigens.

A comparative evaluation of six licensed radioimmunoassay kits for the detection of hepatitis B surface antigen (HBsAg) has been performed. Each method met the federal licensure requirements for the test. The performance of the kits varied considerably, however, when they were challenged to the limits of their sensitivities. During the period December 1978 through March 1979, four kits were judged to be of equivalent high sensitivity, whereas two were less sensitive. Three of the kits, including two of those with high sensitivity, generated a high (6%--7%) proportion of false reactive results. The sensitivities of all kits decreased during the shelf lives of the reagents.