Concentrados de plaquetas procedentes de sangre total (buffy coat) u obtenidos por aféresis; ¿qué producto emplear?

Avatrombopag for the management of thrombocytopenia in patients with chronic liver disease

Severe thrombocytopenia (platelet count < 50 x 109/l) is the most frequent hematological disorder in patients with chronic liver disease, affecting 64-84 % of individuals with cirrhosis. The pathophysiological mechanisms that underlie thrombocytopenia are complex, but the reduction of thrombopoietin levels is considered to play a key role. Until recently, there was a continuous debate about the optimal management of patients with chronic liver disease and whether low platelet counts require a scheduled invasive procedure. Transfusion of platelet concentrates is considered to be the standard treatment, but has major limitations such as its short lifespan, limited efficacy and relevant adverse effects. Avatrombopag is an oral thrombopoietin receptor agonist that induces megakaryocytic proliferation and differentiation and platelet production. It has been approved by the Spanish Agency of Medicines and Health Products for the treatment of severe thrombocytopenia in adult patients with chronic liver disease before scheduled procedures, to decrease the risk of bleeding. Randomized trials have demonstrated that this agent is effective in maintaining platelet counts above 50 × 109/l over a period of more than two weeks, with a similar safety profile to the placebo. In this article, we review avatrombopag in the treatment of thrombocytopenia in patients with chronic liver disease. Furthermore, the main differences of this intervention in comparison to the previous standard of care therapy are discussed.

Quality and safety measures in transfusion practice: The experience of eight southern/eastern Mediterranean countries

BACKGROUND AND OBJECTIVES

Blood transfusion is inherently associated with risks, and little is known regarding the available quality and safety measures in developing countries. No studies or census has been carried out, and therefore, no data on this compelling issue are available.

MATERIALS AND METHODS

Data emanating from eight Arabic eastern/southern Mediterranean countries who responded to five surveys were collected and tabulated.

RESULTS

Asepsis during phlebotomy, screening for serological and immuno-haematological parameters and appropriate storage conditions are maintained across all countries. Variations in blood component processing exist. Universal leucoreduction is systematically applied in Lebanon. Nucleic acid testing is only performed in Egypt. Aphaeresis procedure, leucoreduction and quality control for blood components are virtually inexistent in Mauritania. Written donor questionnaire is absent in Algeria and Tunisia. Most donor deferral periods for infectious agents are inconsistent with international standards.

CONCLUSION

Gaps in the processing and in the quality/safety measures applied to the manufacture of blood components are quite evident in most eastern/southern Mediterranean countries. The decision of establishing an effective collaboration network and an independent body - aside from WHO - composed of specialists that oversees all transfusion activities in these countries is certainly a crucial step towards ensuring an optimum level of blood safety.

Defining an appropriate leucoreduction strategy by serial assessment of cytokine levels in platelet concentrates prepared by different methods

Background and Objectives:

Different methods of platelet concentrate preparations leave behind certain number of residual leukocytes, accounting for most of the febrile nonhemolytic transfusion reactions, especially in multitransfused patients. Various inflammatory cytokines, such as tumor necrosis factor-α (TNF-α), interleukin-1β (IL-1β), and IL-6 are generated during storage and have been implicated for these adverse effects. We have studied the levels of these cytokines and their correlation with leucocyte contents in platelet concentrates prepared by three different methods.

Study Design and Methods:

Five pools of platelet rich plasma platelet concentrates (PRP-PC) and buffy-coat platelet concentrates (BC-PC) each were prepared and divided into two halves. One half of the pool was leucofiltered (LF), whereas the other half was stored as such. Ten apheresis units were also included in the study. All the platelet concentrates were assessed for leucocyte load and cytokine content (IL-1β, IL-6, and TNF-α) on different days of storage (0, 3, and 5) using Nageotte chamber and commercially available immunoassays respectively.

Results:

There was a statistically significant rise in cytokine levels (IL-1β, IL-6, and TNF-α) in nonleucofiltered (NLF) random donor platelet concentrates (RDPs) (PRP-PC and BC-PC) during storage (day 3 and 5) whereas LF RDP concentrates (PRP-PC and BC-PC) and apheresis platelet concentrates (AP-PC) did not show any significant rise in cytokine levels (on day 3 and 5) over the baseline values at day 0.

Conclusion:

This data suggests that although AP-PCs are superior to PRP-PC (NLF) and BC-PC (NLF) in terms of in vitro quality control parameters and cytokine generation during storage, BC-PC mode of platelet preparation followed by leucofiltration is the best method to store platelets and minimise the cytokine accumulation. This strategy is best suited for transfusion in multitransfused hematooncologic patients, who cannot afford single donor apheresis platelets.

Legal and ethical issues in safe blood transfusion

Legal issues play a vital role in providing a framework for the Indian blood transfusion service (BTS), while ethical issues pave the way for quality. Despite licensing of all blood banks, failure to revamp the Drugs and Cosmetic Act (D and C Act) is impeding quality. Newer techniques like chemiluminescence or nucleic acid testing (NAT) find no mention in the D and C Act. Specialised products like pooled platelet concentrates or modified whole blood, therapeutic procedures like erythropheresis, plasma exchange, stem cell collection and processing technologies like leukoreduction and irradiation are not a part of the D and C Act. A highly fragmented BTS comprising of over 2500 blood banks, coupled with a slow and tedious process of dual licensing (state and centre) is a hindrance to smooth functioning of blood banks. Small size of blood banks compromises blood safety. New blood banks are opened in India by hospitals to meet requirements of insurance providers or by medical colleges as this a Medical Council of India (MCI) requirement. Hospital based blood banks opt for replacement donation as they are barred by law from holding camps. Demand for fresh blood, lack of components, and lack of guidelines for safe transfusion leads to continued abuse of blood. Differential pricing of blood components is difficult to explain scientifically or ethically. Accreditation of blood banks along with establishment of regional testing centres could pave the way to blood safety. National Aids Control Organisation (NACO) and National Blood Transfusion Council (NBTC) deserve a more proactive role in the licensing process. The Food and Drug Administration (FDA) needs to clarify that procedures or tests meant for enhancement of blood safety are not illegal.

Estimating the residual risk for HIV, HCV and HBV in different types of platelet concentrates in Germany

BACKGROUND AND OBJECTIVES

We estimated and compared the residual risks due to window-period donations for pooled and apheresis platelets in Germany using a modification of a previously described statistical model. This model directly utilizes the reported interdonation intervals before a positive donation and reflects in this aspect the look-back procedures used in haemovigilance.

MATERIALS AND METHODS

Data from the German National Blood Donor Surveillance System for the years 2006-2012, including reports about donations from repeat donors with confirmed positive test results for HIV, HCV and HBV, were used to estimate the risk of undetected infectious units for both pooled and apheresis platelets.

RESULTS

Demographics of whole-blood and apheresis donors differed in age, gender, catchment area and interdonation interval. These differences impact on the prevalence and incidence of transfusion relevant infections and consequently the residual risk. The estimates for the residual risks for pooled and apheresis platelets were comparable. For HIV, there was no significant difference, for HCV apheresis platelets had a lower residual risk, whereas pooled platelets had a lower risk for undetected HBV infections.

CONCLUSION

These findings do not support calls for a shift to an apheresis platelets-only policy in Germany.

Quality control of leucocyte-depleted platelet concentrates obtained by buffy-coat method

OBJECTIVES

Quality control results on leukoreduced buffy-coat platelet pools during the 7-year period (2005-2011) are presented with the aim to assess their overall quality and trends recorded during the study period.

METHODS

Data of the Quality Assurance Department, Croatian Institute of Transfusion Medicine were used in the study. Measurement results of all study parameters are presented for the entire study period, while the rate of controlled platelet pools consistent with the specified quality requirements is additionally presented for each study year.

RESULTS

The mean component volume was 50 ± 9 mL per 6 × 10(10) platelets (91.5% of conformable results), mean platelet count 7.81 ± 1.26 × 10(10) per single unit equivalent (97.5% of conformable results), mean leucocyte count 0.01 ± 0.08 × 10(6) per single unit equivalent (99.6% of conformable results), and mean pH 7.45 ± 0.16 (99.4% of conformable results). Bacteriologic testing showed negative result in 99.8% of tested components.

CONCLUSION

Study results indicated the results of platelet pool quality control to be highly conformable with the specified quality requirements. It is illustrated how simple interventions in the preparation process can have significant impact on product quality improvement and thus on redefining quality requirements.