No increased benefit, higher adverse event risk with prophylactic platelet transfusion in dengue
Prophylactic platelet transfusion did not improve outcomes in adults with dengue and thrombocytopenia, and may be associated with an increased risk of adverse events, a recent study found.
“Results from our randomized trial provide evidence to support present [World Health Organization] guidelines ... in recommending against prophylactic platelet transfusion in patients with low platelet count,” said the researchers.
In this open-label, randomized, superiority trial conducted in five hospitals in Singapore and Malaysia between April 2010 and December 2014, 372 individuals aged ≥21 years with laboratory-confirmed dengue and thrombocytopenia (≤20,000 platelets/µL) were randomized to receive prophylactic platelet transfusion plus supportive care (transfusion group, n=188, median age 44.3 years, 74 percent male) or supportive care only (control group, n=184, median age 45.2 years, 77 percent male). [Lancet 2017;doi:10.1016/S0140-6736(17)30269-6]
Patients in the transfusion group were given four units of pooled platelets per day, while supportive care comprised bed rest, fluid therapy, and fever and pain medications.
The primary endpoint, incidence of clinical bleeding by day 7 or discharge from hospital, was comparable between groups, experienced by 40 patients who received prophylactic platelet transfusion and supportive care compared with 48 patients who received supportive care only (21 percent vs 26 percent, relative risk [RR], 0.81, 95 percent confidence interval [CI], 0.56–1.17; p=0.16). Incidence of clinical bleeding remained comparable between groups by day 21 (22 percent vs 27 percent, RR, 0.83, 95 percent CI, 0.58–1.19; p=0.34).
The incidence of bleeding by day 7 was similar between the transfusion and control groups in individuals with baseline platelet counts of <10,000/µL (p=0.41) and <5,000/µL (p=0.78).
“[These findings indicated] a lack of efficacy at any degree of thrombocytopenia,” said Dr Muhammad Zaman Khan Assir from the Allama Iqbal Medical College and Jinnah Hospital, Lahore, Pakistan, in a separate editorial. [Lancet 2017;doi:10.1016/S0140-6736(17)30545-7]
The most common type of bleeding was gingival bleeding experienced by 21 and 32 patients by day 7 in the transfusion and control groups, respectively.
Incidence of severe bleeding (at day 21) was low in the study population and similar between the transfusion and control groups (three vs seven patients, RR, 0.42; p=0.21).
The incidence of adverse events was higher in patients in the transfusion group compared with the control group (13 vs two, RR, 6.26, 95 percent CI, 1.43–27.34; p=0.0064). Nine adverse events were deemed possibly, probably, or definitely related to transfusion, six were mild-to-moderate and included urticaria (n=3), maculopapular rash, pruritus, and chest pain (one incident each), while another three led to severe events (one incident each of anaphylaxis, transfusion-related acute lung injury, and fluid overload).
“With similar bleeding risk and platelet recovery, as well as potential harm, prophylactic platelet transfusion should not be recommended,” said the researchers.
“A strategy to withhold prophylactic platelet transfusion in adult dengue is expected to substantially reduce healthcare costs, ease demand on blood banks, and reduce harms related to platelet transfusion,” said Assir.
The researchers acknowledged that the results may not extend to children or individuals in other countries. A higher dose of prophylactic platelet transfusion may also have produced different results. Furthermore, although female sex tends to be a risk factor for bleeding in dengue, [Southeast Asian J Trop Med Public Health 2012;43:890-899] women were underrepresented in this cohort, they said.
“Bleeding risk in dengue – which can be due to a range of other factors – might not be improved by platelet transfusion alone,” they said, and recommended that future research look into the outcomes of prophylactic platelet transfusion in children and for severe bleeding.