Four-year safety follow-up of the tetravalent dengue vaccine efficacy randomized controlled trials in Asia and Latin America.

OBJECTIVE: Our objective was to describe the risk of hospital admission for virologically confirmed dengue (VCD) and the risk of clinically severe hospitalized VCD occurring up to 4 years after the first dose (years 1 to 4) in three randomized clinical trials comparing tetravalent dengue vaccine with placebo. METHODS: The relative risks (RR) for hospitalized VCD from first dose to year 4 were estimated by year and age-group in individual and combined studies. RESULTS: Overall, from Year 1 to Year 4, 233 and 228 participants had at least one episode of hospitalized VCD in the vaccinated (n = 22 603) and placebo (n = 11 301) groups, respectively (RR = 0.511, 95% CI 0.42-0.62). Among these, 48 and 47 cases, respectively, were classified as clinically severe. In children aged ≥9 years, 88 and 136 participants had at least one episode of hospitalized VCD in the vaccinated (n = 17 629) and placebo (n = 8821) groups, respectively (RR = 0.324; 95% CI 0.24-0.43). In vaccinated participants aged <9 years, particularly in those aged 2-5 years, there were more hospitalized VCD cases compared with the control participants in Year 3 but not in Year 4. The overall RR in those aged <9 years for Year 1 to Year 4 was 0.786 (95% CI 0.60-1.03), with a higher protective effect in the 6-8 year olds than in the 2-5 year olds. CONCLUSIONS: The overall benefit-risk remained positive in those aged ≥9 years up to year 4, although the protective effect was lower in years 3 and 4 than in years 1 and 2.

Thawed cryoprecipitate stored for 6 h at room temperature: a potential alternative to factor VIII concentrate for continuous infusion.

Continuous infusion (CI) of factor VIII concentrates has been demonstrated to be cost-effective method in maintaining stable levels of FVIII activity in haemophilia A patients with major bleeding or undergoing major surgery. Cryoprecipitates remain the major source of FVIII in developing countries-like the Philippines because of limited availability and high cost of concentrates. To support the use of cryoprecipitate as alternative to FVIII concentrate for CI in centres with no factor concentrates, FVIII levels in 37 bags of random cryoprecipitate were measured at 0, 2, 4 and 6 h after thawing, kept at room temperature with bacteriological culture studies performed on the sixth hour. The mean FVIII content at hour 0 was 108.10 U per bag. Type ORh+ blood had lower FVIII content (+/-78.91 U per bag) compared with blood types ARh+ (+/-121.64 U per bag) and BRh+ (+/-117.04 U per bag). The units stored <6 months had higher FVIII content (+/-117.74 U per bag) compared with those stored for over 6- but <12-months (+/-66.77 U per bag). The mean rate of decline of FVIII activity at 2, 4 and 6 h was statistically significant at 10.35% (P = 0.000), 21.49% (P = 0.000) and 29.41% (P = 0.000) from baseline, respectively, using the paired t-test. Similar finding was found across different blood types and storage duration. Only one of 37 bags grew Staphylococcus aureus on day 10 of incubation.

Cryoprecipitate-removed plasma 'cryo-removed plasma' as a source of factor IX in the treatment of haemophilia B.

Fresh frozen plasma (FFP) is the main source of factor IX (FIX) in the treatment of bleeding episodes of haemophilia B in the Philippines. Cryoprecipitate-removed plasma otherwise known in the Philippines as cryosupernate, is a by-product of cryoprecipitate preparation. These blood products expire in storage or are just thrown- away because of less demand for clinical use. By theory, this product should have almost the same amount of FIX as in FFP, therefore can be used in the treatment of haemophilia B. There is no local data on the actual FIX content of the cryoprecipitate-removed plasma. Hence, the authors established these data to support the use of this product. Eighty-three bags of cryoprecipitate-removed plasma received from three different blood banks in Manila, Philippines were tested for FIX activity using an activated partial thromboplastin time (APTT)-based one-stage FIX assay. The FIX content in each bag of cryoprecipitate-removed plasma was calculated by multiplying its volume in mL with that of FIX activity per mL of plasma measured in vitro. The total mean FIX content per bag was 212.20 U (+/-88.98) exceeding the contents set by the American Association of Blood Banks (AABB, 70-90 U). The mean FIX activity per bag was 127.62% (+/-38.23) with the mean volume of 164.28 mL (+/-52.23). Statistically significant difference on volume (P = 0.000) was found across the three sources resulting to a significant variation of the actual FIX content (P = 0.000).

Prothrombin time and partial thromboplastin time as a predictor of bleeding in patients with dengue hemorrhagic fever.

Eighty-nine pediatric patients admitted at the University of Santo Tomas Hospital from June to December 1992, with the clinical diagnosis of dengue hemorrhagic fever (DHF) were studied with the following objectives: To determine the possible use of hematocrit, platelet count, prothrombin time (PT) and partial thromboplastin time (PTT) as predictors of bleeding and outcome in patient with DHF. The following were established: PTT can be an index in predicting bleeding in DHF. The tendency to bleed is greater with prolongation of > 30 seconds; platelet count can be a predictor of mortality, with death six times greater among those platelet count < 50,000/microliters than those whose platelet count was > 50,000/microliters. PT can also predict bleeding in patients with DHF.