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After two patients received bacterially contaminated platelet transfusions, a prospective surveillance program was instituted to perform Gram staining and microbiologic culturing of platelets at the time of transfusion. In 12 months, 3141 random-donor platelet pools (prepared from 14,481 units) and 2476 single-donor apheresis units were cultured. All single-donor apheresis units were sterile, but 6 (0.19%) of the random-donor pools were found to be bacterially contaminated, with 1 unit of 5 in the pool being the source in each case. Contaminants were Staphylococcus epidermidis (4 cases), Bacillus cereus (1), and Staphylococcus aureus (1) at counts of 0.5 x 10(2) to 10(11) colony-forming units per mL in platelet pools and 10(3) to 10(13) colony-forming units per mL in source units. The contamination rate for units transfused at < or = 4 days (1.8/10,000) was significantly lower than that at 5 days (11.9/10,000; p < 0.05), as was the magnitude of contamination (p < 0.05). Use of the pretransfusion Gram stain on 4- and 5-day-old platelet pools was 100 percent sensitive (4/4 true positives) and 99.93 percent specific (1 false positive) in detecting contaminated pools. These data define the extent and magnitude of platelet bacterial contamination and demonstrate the efficacy of the pretransfusion Gram stain on platelet units stored for 4 and 5 days in preventing the transfusion of heavily contaminated units. It is concluded that the risk of platelet contamination is related to the duration of component storage.(ABSTRACT TRUNCATED AT 250 WORDS)

A prospective phase II trial was conducted to assess the feasibility, tolerance, and efficacy of a device designed for selective removal of rheumatoid factor from the plasma of rheumatoid arthritis patients. The device contained terpolymer hydrogel-coated plates with chemically attached, aggregated human immunoglobulin G, and it operated as an immunoaffinity column. Sixty-one patients aged 25 to 73 underwent weekly plasmapheresis treatments (the primary therapy phase). During the trial, patients continued current rheumatoid arthritis medications without dose adjustments. All patients received two to six treatments (primary therapy). Responding patients were eligible to continue apheresis treatment every 2 to 6 weeks (maintenance therapy). No serious, untoward side effects were noted in the course of this study; of 640 treatments, only 2 (in different patients) were aborted, one because of complaints of dizziness and angioedema and the other because of chest tightness and shortness of breath. Except for a significant (p less than 0.05) decrease in serum iron, no significant changes in complete blood count, serum electrolytes, renal and hepatic function tests, or serum C3 and C4 were noted. Although the trial was not designed to determine clinical efficacy, patients noted less morning stiffness, longer time to onset of fatigue, and improved global pain assessment (p less than 0.004); significant objective improvements were noted in joint pain, tenderness, swelling, and the number of affected joints (p less than 0.001). One-half of the treated patients had at least a 50 percent improvement in objective measures of antirheumatic activity.(ABSTRACT TRUNCATED AT 250 WORDS)

We studied the transfusion response from random donor platelet concentrates in 15 stable multitransfused, thrombocytopenic patients by comparing the platelet counts measured before and 20 hours after transfusion. The observed platelet increments were corrected (corrected increment, C.I.) for the number of units of platelet concentrate transfused and the patient's body surface area in square meters (platelets/microliter per unit/m2). Using platelet concentrates stored for less than 24 hours, the patients achieved a median C.I. of 9500 (range: 5000-18,000). When platelet concentrates stored for 24 to 48 hours or 48 to 72 hours were given, the median C.I. markedly decreased to 1000 (range: 0-4800) and 0 (range: 0-5100), respectively (p less than 0.001). These differences could not be explained by further recipient alloimmunization. Transfusion with platelet concentrates less than 24 hours old on a second occasion, bracketing the transfusions of older platelet concentrates, resulted in a median C.I. of 7200 (range: 5400-14,500). Similar results were obtained in three patients when HLA-identical sibling platelet concentrates were employed. In vitro tests, including pH, morphology, and aggregation, demonstrated no statistically significant differences among the platelet concentrates stored for less than 24 hours, 24 to 48 hours, and 48 to 72 hours. These studies suggest that, although platelet concentrates can be stored for 72 hours without loss of in vitro function, the in vivo recovery is significantly diminished after 24 hours of storage, and preferably patients should not be transfused prophylactically with platelet concentrates greater than 24 hours old.