Single-donor Platelet Transfusions Research Articles

The Effect of High Intensity Interval Exercise on Platelet Engraftment in Autologous Bone Marrow Transplantation (BMT).

Background: Thrombocytopenia is a frequent complication after hematopoietic stem cell transplantation (HSCT). Although platelet transfusion is the most used treatment for severe thrombocytopenia, it is associated with well-established risks. High-intensity interval exercise (HIIE) results in thrombocytosis. Therefore, this study aimed to reduce thrombocytopenia by increasing platelet count through exercise. Materials and Methods: Twenty lymphoma and multiple myeloma patients were divided into HIIE and control groups. To determine the maximal exercise capacity, patients in the HIIE group performed a graded exercise test. All patients received granulocyte colony-stimulating factor for 5 days,followed by a HIIE trial. After 5 min warm up at 10 to 20% of peak power, patients in the HIIE group performed an HIIE protocol that included 12 intervals of one-minute work at 100% peak power interspersed by one-minute active rest at 20% of peak power. Patients in the control group were seated for the same duration without any physical activity. Two blood samples were taken before and immediately after the trials and were analyzed for measuring complete blood count. Results: Platelet count on the day of platelet engraftment in the HIIE group was significantly higher than in the control group (P=0.02). Single-donor platelet transfusion was significantly lower in the HIIE group than in the control group (P=0.05). Conclusion: Based on the findings of the present study, a short bout of HIIE had a positive effect on platelet engraftment through thrombocytosis and reduced platelet transfusion and its complications, which could be a useful strategy for HSCT patients.

Dental management of Fanconi anemia: a rare congenital disorder

PurposeFanconi anemia is a rare inherited genetic disorder that is characterized by all three defective blood cell lines such as reduced red blood cells, platelets, and white blood cells. This makes the individual susceptible to spontaneous oral bleeding and prone to oral infections including periodontal diseases.MethodDental management of individuals with Fanconi anemia can be a difficult task as these individuals have a tendency for uncontrolled hemorrhage and infections after any simple dental procedure. This case report highlights the oral manifestations and management of the same in such individuals taking into consideration the complications in such rare diseases.ResultIn this case report, the individuals’ oral manifestations and spontaneous oral bleeding were successfully managed by preventive single-donor platelet transfusion, factor VII transfusion, and local tranexamic acid usage during the dental interventions along with parental counseling.ConclusionFanconi anemia being a rare inherited disorder is often difficult to manage due to a lack of knowledge and awareness among the dental clinicians. This case report attempts in highlighting the same and spreading awareness among the clinicians.

Alloantibody Levels, Immunoglobulin Degradation Products, and Platelet Transfusion Response over Successful Desensitization of Severe Alloimmune Platelet Refractoriness with a Novel IgG-Targeted Enzyme Therapeutic

INTRODUCTION Alloimmune platelet refractoriness (APR), an insufficient response to platelet transfusion due to anti-HLA alloantibodies, affects ~25% of acute myeloid leukemia (AML) patients. In APR, HLA- or crossmatch-compatible platelet units may not be identifiable, precluding transfusion and increasing hemorrhage risk. Single antigen bead testing (SAB) semi-quantitates antibody levels against cognate HLA antigens in units of mean fluorescence intensity (MFI). MFI >3,000 suggests an incompatible platelet antigen for transfusion. Imlifidase, an IgG-specific cysteine protease, cleaves IgG first into single-cleaved IgG (scIgG) with limited Fc-mediated function, then into inactive F(ab') fragments 1. We previously reported successful desensitization and provision of permissive platelet transfusions in an APR patient following desensitization treatment with imlifidase. Here we report pre- and post-desensitization alloantibody (PDAb) levels in correlation with IgG degradation products and response to single donor platelet transfusion. CASE As described previously 2, a 43-year-old highly sensitized (calculated PRA [cPRA] 99.9%) woman with AML and history of life-threatening thrombocytopenic hemorrhage secondary to APR presented for matched-unrelated donor stem cell transplantation. Nationwide, few compatible platelet units were identified to support her through the anticipated platelet nadir. Following conventional desensitization, cPRA did not change significantly. Following imlifidase-desensitization [0.25 mg/kg IV (D-1 and D1)], cPRA decreased significantly. 7 single-donor, antigen-avoidance platelet units produced corrected count increments (CCI) [median (interquartile range) of 6,000 (500-7500)]. The patient experienced no hemorrhage and was discharged stable, post-platelet engraftment on D+19. METHODS With IRB approval, patient data and samples (D-16; D-1 post-conventional desensitization with rituximab and therapeutic plasma exchange; D0 post-imlifidase dose 1; D2 post-imlifidase dose 2; and D7, D14 and D29 follow-up samples) were collected. Serial dilutions of patient D-1 serum were tested with SAB (LABScreen single antigen, One Lambda/ThermoFisher, West Hills, California). SDS-PAGE (gradient gel, non-reduced conditions), Western Blot (antiF(ab') detection), and SAB were performed and acceptable antigens (to molecular specificity, targeted by MFI ≤3,000) were compared over the clinical course. Summative MFIs targeting transfused single donor platelet units were compared with 1-hour CCI. Wilcoxon matched-pairs signed rank for matched, nonparametric values and Chi-squared or Fisher's exact for categorical variables were used. P <0.05 was significant. RESULTS/DISCUSSION The D-1 sample (post-conventional desensitization, pre-imlifidase) showed exquisite HLA sensitization. The highest Class A and B antibodies demonstrated an effective MFI of >4,000,000, each (Fig. A). PDAb and the number of unacceptable antigens decreased significantly in D0 (post-imlifidase) vs. D-1 (pre-imlifidase) samples; Intact IgG and scIgG were eliminated from the D0 and D2 samples (Fig. B). Of 7 single donor platelet transfusions, the 5 producing adequate response were each targeted by a summative MFI ≤4,000 (median 4,000 MFI, range 300-4,000). The 2 units producing inadequate CCI response were targeted by summative MFI >4,000 (5,050, 4,900-5,200), suggesting a threshold summative MFI precluding adequate response. CONCLUSIONS Here we show that the patient's pre-desensitization alloantibody levels significantly exceeded the analytical range of the SAB; PDAb levels declined significantly from baseline, correlating with lack of intact IgG and scIgG following imlifidase; and permissive transfusions (CCI >5,000) were seen to platelets targeted by ≤4,000 summative MFI. These results suggest imlifidase is capable of effective desensitization despite profound baseline sensitization, with rapid cleavage of intact IgG to F(ab'), resulting in the temporary reduction of unacceptable antigens. Larger scale investigation of imlifidase in desensitization of APR patients requiring significant transfusion over a limited period of time, along with investigation into transfusion strategies in desensitized APR, are warranted. REFERENCES Am J Transpl. 2022;22(3):691-697.Blood. 2022;140 (Suppl. 1):8562-3. .

Case Report On Abnormal Uterine Bleeding with Multi-System Disorders

Autoimmune disease is a condition that attacks the immune system and leads to multi-system disorders like systemiclupus erythematosus and rheumatoid disorders, which initiates self-directed immune responses that result in clinical diseases,mainly in obstetrics conditions like recurrent pregnancy loss, pre-eclampsia are common. The study aimed to identify therelationship between connective tissue disorders and abnormal uterine bleeding patterns. A rare case of abnormal uterinebleeding with a past history of recurrent pregnancy loss was presented in the casualty with excessive menstrual bleeding in astate of hypovolemic shock. The patient complained of generalised malaise, giddiness, breathlessness, and palpitations for thepast 2 months. She suffered recurrent epistaxis for the past 2 months and experienced symptoms like loss of appetite, recurrentvomiting for the past 15 – 20 days, and rashes over the face and cheeks for 6 months. Her haemoglobin was 2.4g/dL, and theplatelets were less than 10,000 with bicytopenia at the time of admission She was shifted to ICU and haemodynamicallystabilized by packed red blood cells, fresh frozen plasma, and platelets. Following this, she was treated with antifibrinolytics, andsevere anaemia was corrected with multiple PRBC transfusions. Multiple single-donor platelet transfusions were also done. Afterrecovery, the patient was discharged with an advice to continue hydroxychloroquine. Immune dysregulation and inflammationtogether contribute to the development of menstrual disorders among women with Rheumatoid Disorders which can be wellmanaged with systematic therapeutic plans at the initial stage.

A Rare Case of Post-Partum Hemorrhage with Refractory Thrombotic Microangiopathy, and Hepatic Infarction: A Diagnostic Dilemma with High Mortality

We are presenting a very rare and unique case of postpartum hemorrhage with excessive blood loss requiring 6 units of packed red cells, 2 units of single donor platelet transfusions, 4 fresh frozen plasmas, and 4 cryoprecipitates. The patient developed a life-threatening spectrum of thrombotic microangiopathy which is known to result in pregnancy from eclampsia, pre-eclampsia, thrombotic thrombocytopenic purpura, typical and atypical hemolytic uremic syndrome, and hemolysis, elevated liver enzymes, low platelets syndrome and in non-pregnant patients with a wide differential diagnosis. The patient required 7 sessions of plasma exchange along with systemic steroids. During her illness, she developed rising liver enzymes and bilirubin, diffuse intravascular coagulation, renal failure, alveolar hemorrhage, and acute fulminant hepatic failure. A contrast-enhanced computed tomography scan revealed multiple areas of liver infarction with patent hepato-portal vessels. The patient required continuous renal replacement therapy and high supportive care. She stayed in the intensive care unit for 9 days, developed multi-organ failure, and finally expired. It is highly imperative to be aware of the complications of postpartum hemorrhage, as it should be treated promptly to minimize the possible cascade of multi-organ failure with high maternal and fetal mortality. Liver transplantation is the only possible radical therapy in cases with fulminant hepatic failure, worth considering, if clinically possible and applicable.

A comparative study of the transfusion effect of single donor apheresis platelets versus random donor platelets in the management of severe dengue infection in children

Background: The national vector-borne diseases control programme (NVBDCP) dengue clinical care guidelines 2014 clearly specify the indications for platelet transfusion in dengue fever. The goal of the study was to see how successful guideline-driven platelet transfusion was, as well as whether single donor platelet (SDP) transfusion was superior to random donor platelet transfusion (RDP), which was widely thought but unproven.Methods: Two ml of the patient's blood were collected in EDTA tubes at two distinct times: once before the transfusion and the other 24 hours afterwards and the data were assessed using corrected count increments (CCI), percentage recovery (PR) and other criteria.Results: Platelet increments were substantially larger with SDP transfusions at 24 hours than with RDP transfusions (p<0.01 for 24 hours post-transfusion period). However, in both groups, the corrected count increment and percentage recovery were nearly identical and the difference was statistically insignificant.Conclusions: Although post-transfusion increments were considerably higher in SDP patients than in RDP patients, the CCI and PR were similar in both groups of patients. When it comes to the number of donors exposed to patient and leukoreduction, SDP is superior to RDP in terms of logistics. However, in developing countries, SDP may be advised only in selected patients based on accessibility and affordability, due to their high cost and higher technical competence required.

Platelet additive solution suspended apheresis platelets in a tertiary care hospital: A step toward universal single donor platelets.

Transfusion of ABO-compatible single donor platelets (SDP) is preferable for better outcomes over group switchover SDP. The use of SDP containing ABO-incompatible plasma is associated with a risk of allergic and acute hemolytic transfusion reactions. Moreover, high titer O group donors SDP impose a further threat to patient safety. Platelet additive solution (PAS) is used worldwide for the storage of platelets which reduces plasma volume available in SDP. SSP + (Macopharma) is one such PAS which can provide improved availability, logistical management, decrease wastage, and improvement in patient safety. The aim of this study was to assess the feasibility of using PAS to obtain low titer SDP units which can be utilized across a larger patient population and to study quality control parameters of these units. The study was performed in the department of Transfusion Medicine from June 2017 to January 2018 after clearance from the Institutional Review Board. The study design comprised two cohorts (A and B). In cohort A, the temporal trend of in-vitro changes in the quality parameters was tested and analyzed for PAS modified and unmodified products on days 1, 5 and 7. In cohort B, the original plasma from the SDP donors of all blood group donors except the AB group was tested for antibody titers before (prepreparation) and after modification (postpreparation) by PAS. In cohort A, in the control group, there was a significant change in the mean platelet volume, potassium, and bicarbonate levels from day 1 to day 7, whereas no significant change in the biochemical parameters was noted in the study group where PAS was used. In cohort B, on comparing the anti-A and anti-B, before and after modification of SDP with PAS, there was a significant reduction in the median titers across all the groups studied. PAS added SDP is an efficient strategy to reduce the ABO-antibody levels significantly. PAS added SDP also helps in the better inventory management of available groups.

To Study the Effectiveness of Platelet Transfusion in Management of Dengue Patients in Tertiary Care Hospital

Background: Dengue has been emerging as rapidly spreading and dreaded mosquito borne disease caused by the bite of Aedes Aegypti Mosquito. Clinical features are variable and presents with Dengue fever or Dengue Hemorrhagic fever or more severe Dengue shock syndrome. Thrombocytopenia is presenting feature in in all Dengue cases and some often presents with bleeding. Platelet transfusions are given in patients with haemorrhagic symptoms. Present study thus aims to study the effectiveness of platelet transfusion in management of Dengue patients with Dengue haemorrhagic fever and Dengue shock syndrome. Results: In present study, a total of 20 patients were diagnosed as dengue confirmed cases by serological testing methods. Out of 20, 12 (60%) patients had dengue fever with platelet count in range of 50,000-80,000 per μl. Two patients with Dengue fever had Petechial spots with platelet count in range of 50,000 per μl and were given prophylactic Single Donor Platelet Transfusions. Eight patients (40%) presented with Dengue Haemorrhagic fever and platelet count of < 20,000 per μl. These patients were given single donor platelet transfusions. Six patients responded good with CCI of > 30,000 per μl and 2 patients recorded as non-responders. Conclusion: This study suggests that 25% Platelet transfusions are inappropriate. Platelet transfusions are more effective when it is given to patients with platelet count <20,000 per μl. Platelet transfusion should be given based on platelet count and hemorrhagic manifestations, as this decreases hospitalization of patients and complications of dengue.

The burden of immune-mediated refractoriness to platelet transfusions in myelodysplastic syndromes.

A retrospective analysis of MDS patients enrolled in the SA-MDS registry was performed. HLA data was analyzed from January 2003 to 30 June 2017 to ensure minimum follow-up of 2 years. During the study period, 341 of 681 (50%) MDS patients required at least one PLT transfusion, with 29 of 341 (9%) of all PLT transfusion patients requiring HLA-matched PLT transfusion for PLT-R. Of these 29 patients, 70% were females treated with disease-modifying therapies suggesting that these patients are at high risk of HLA alloimmunization. Immune-mediated PLT-R is common in MDS and can be expensive and difficult to manage once it occurs. Therefore, PLT transfusion practices should be optimized, especially for female MDS patients planned for disease-modifying therapies. This can help save time and streamline management, especially in the provision of PLT products for these patients, where the consequences of alloimmunization and PLT-R can be severe.

Trastuzumab-Induced Severe Thrombocytopenia: A Case Report and Literature Review

We present a 29-year-old woman with pT2N0M0 breast cancer, histological diagnosis of invasive ductal carcinoma, ER and PR low positive, and HER-2 (3+). The patient developed trastuzumab-induced thrombocytopenia in 6 hours after an intravenous infusion of trastuzumab at the second cycle of trastuzumab treatment with the symptom of abnormal uterine bleeding. Laboratory exam revealed a sharp drop of platelet count down to 3×109/L. With the treatment of single-donor platelet transfusions, glucocorticoids, oxytocin and thrombopoietic drugs, the platelet count recovered completely in 11 days. This case was confirmed to be severe thrombocytopenia induced by trastuzumab, and retreatment with trastuzumab was not attempted. With increasing clinical utilization of trastuzumab, clinicians are likely to encounter more life-threatening trastuzumab induced severe thrombocytopenia. By this case report and literature review, we hope to increase the awareness, attach the attentions to this condition, and help with the effective treatment.

Adding to platelet safety and life: Platelet additive solutions.

BACKGROUND:Platelet additive solutions (PAS) are crystalloid nutrient media used in place of plasma for platelet storage. They replace 60%–70% of plasma in platelet components, so the amount of storage plasma can be decreased. Platelets in PAS have lower risk for allergic transfusion reactions with equivalent clinical efficacy for controlling bleeding.AIM:The aim of this study is to evaluate the clinical and laboratory efficacy of PAS-platelets.MATERIALS AND METHODS:A total of 1674 single donor platelet (SDP) were collected in PAS in the month of June to September 2016 by different apheresis systems. The quality control tests were done on 356 units in 4 months. Total number of SDP were processed with Amicus device (n = 232), Trima Accel (n = 84), and MCS+ (n = 40). The parameters analyzed were antibody titer of anti-A and anti-B, volume, platelet count, pH, bacterial contamination, and reporting of adverse transfusion reaction. Antibody titers were checked by tube technique, and platelet counts were checked by hematology analyzer Sysmex poch 100i. The swirling was checked manually, and pH was checked with pH strips.RESULTS:Out of 356, 164 units were O group, 113 units were B group, 68 units were of A group, and the remaining 11 units were of AB Group. Anti-A and anti-B titer was significantly reduced in PAS-SDP and found 1:32 or less for all the units. All the units found negative for bacterial contamination. No transfusion reaction was reported of the units transfused. All other quality parameters for platelets also found satisfactory after implementing the additive solution.CONCLUSION:The ABO antibody titers were significantly reduced after addition of PAS. This facilitates the ABO incompatible SDP transfusion and helps in inventory management. The risk of allergic transfusion reaction decreases after reducing the amount of plasma from SDP units. Using PAS-SDP certainly improve the inventory management for platelets with no compromise on clinical and laboratory efficacy.

Extended Small-Dose Platelet Transfusions in Multitransfused Hemato-Oncological Patients: A Single-Center Experience

Background: Refractoriness to platelet transfusion, prevalent among 15-20% of hemato-oncological patients, is associated with multitransfusions and inferior outcomes. We evaluated the effectiveness of extended slow-dose transfusion (ESDT) in increasing platelet increments in multitransfused patients. Methods: Patients treated after the implementation of ESDT were compared with historical controls treated with standard single-donor platelet (SDP) transfusions. Cohorts of early and late recipients were assembled for comparison, i.e. the 8th or 9th and 11th platelet unit per patient, respectively. Patients in the ESDT group received transfusions equal to half an SDP unit, administered over 4 h. Effectiveness was defined as a higher corrected count increment (CCI) at 1, 12, and 24 h after transfusion. Results: In the early-recipients cohort, 24-h-posttransfusion increments were available for 29 ESDT patients and 6 standard patients, and did not differ significantly between the groups (p = 0.078). The 24-h-posttransfusion increment was available for 20 ESDT patients and 7 standard patients in the late-recipients cohort. The CCI was significantly higher in the ESDT group (p = 0.042). ABO compatibility improved the CCI (p = 0.01). Conclusions: ESDT demonstrated slightly higher increments at 24 h after transfusion in late recipients, suggesting this could be a cost-effective approach for the treatment of thrombocytopenic multitransfused hemato-oncological patients.

Various aspects of plateletpheresis: Its impact on donor and patients

Background and Aim: Platelet transfusion plays an important role in the treatment of hematological, oncological, surgical, and transplant patients. Aphaeresis technology is widely available in the world and some part of India, but it is new for our region. The present study aims at various aspects of plateletpheresis including donor safety, donor hematological changes following single donor platelet (SDP) donation, quality of product, and impact on patient following SDP transfusion. Materials and Methods: Preprocedural hematological count such as total platelet count (TPC), hemoglobin, red blood cells, and white blood cells count was recorded. All donors were observed for adverse donor reactions. Postdonation (after 30 min) sample was drawn to see the hematological parameters and compared to that of pre donation hematological parameters. Quality control of all SDP products was done. All recipients were observed for any transfusion reactions. Post 24 h transfusion sample was obtained from the SDP recipient and compared to that of pretransfusion sample to see the platelet increment. Results: A total of 135 plateletpheresis procedures were performed on cell separator. SDP was collected from the donors as per standard operating procedure. All donors were observed for adverse donor reaction. We found an adverse event with one donor. There was decrease in mean value of all hematological parameters in the postdonation sample. There was no thrombocytopenia either clinically or from laboratory value. Similar trend was seen with double yield collection. Mean acid citrate dextrose (ACD) used was 328, mean blood volume processed 3385 ml, mean product volume was 249 ml, mean time was 76.8 min during the procedure. Quality control of all SDP products was done. Mean yield was found to be 4.18 ± 0.95 × 1011 per unit. A positive correlation was seen between pre TPC of donor and product yield. Post 24 h transfusion sample was obtained from the SDP recipient and compared to that of pretransfusion sample to see the platelet increment. We observed mean increment of platelet count to be 76.15 × 109/L. Overall therapeutic benefit was observed in all cases. Conclusion: The study found that plateletpheresis procedure is very safe from donor point of view and SDP product is effective from recipient's point of view.

Transfusion of ABO-Incompatible HLA-Matched Platelets as Support for Patients with Acute Myeloid Leukaemia Undergoing Chemotherapy

Background: ABO-incompatible human leukocyte antigen (HLA)-matched platelets are used to manage thrombocytopenic patients with anti-HLA-A and/or anti-HLA-B (HLA-A/B) antibodies when ABO-identical donors are not available. This study assessed the effectiveness of ABO-incompatible HLA-matched platelets in an unselected group of patients with acute myeloid leukaemia (AML) undergoing cytotoxic chemotherapy. Material and Methods: The study cohort consisted of 12 AML patients undergoing cytotoxic chemotherapy and administered HLA-matched single donor platelet transfusions. Patients positive for anti-HLA-A/B antibodies were defined as candidates for HLA-matched platelet transfusion. The effectiveness of platelet transfusions was determined by measuring corrected count increments (CCIs). Results: The 12 patients received a total of 128 HLA-matched platelet transfusions. The median CCIs 1 hour after ABO-minor and -major incompatible HLA-matched transfusions were 11.4 (range: 3.2-24.9) and 12.4 (range: 3-37), respectively. There were no significant differences in 1- and 24-hour CCIs among ABO-identical and ABOminor and major incompatible transfusions. Discussion: ABO-incompatible HLA-matched platelets are effective in supporting thrombocytopenic AML patient’s positive for anti-HLA-A/B antibodies and undergoing cytotoxic chemotherapy.

The utility of thromboelastometry in prophylactic platelet transfusion for hematological malignancies

There is still debate on how platelet transfusions should be used to prevent severe bleeding. The aim of our study is to assess the clinical efficacy of thromboelastometry in reducing number of prophylactic platelet transfusions in patients with hematological malignancies. One hundred hematological malignancy patients were included in the study. Six units random donor platelets (RDPs) was given to the first group, three units RDPs was given to the second group, one unit single donor platelets (SDPs) was given to the third group, and 1/2 unit SDPs was given to the fourth group. Before and 15 minutes after transfusion, rotation thromboelastometry (ROTEM) was performed (Pentapharm GmbH, Munich, Germany). ROTEM® parameters did not show any statistical difference between ‘low dose’ and ‘high dose’ random or single donor platelet transfusions. Therefore, low dose platelet transfusion can be considered because of its reduced adverse transfusion reactions and economic burden.

Safety and Efficacy of Eltrombopag in Post-hematopoietic Stem Cell Transplantation (HSCT) Thrombocytopenia.

Twelve adult patients (median age 29.5years) were started on Eltrombopag 25-50mg/day for post-hematopoietic stem cell transplantation (HSCT) thrombocytopenia. All patients were having primary thrombocytopenia after HSCT. No patient had other secondary cause for thrombocytopenia. Two patients were allogenic subsets (1 acute myeloid leukemia i.e., AML and 1 aplastic anemia), and 10 were autologous transplants (3 multiple myeloma, 6 lymphoma and 1 AML). Nine patients were males, three were females. The median time of starting Eltrombopag was 21days post-stem cell infusion (range day +17 to +60) at a median platelet count of 9,000/cmm (range 3,000-11,000/cmm). The median duration for treatment was 29days. Median total dose of 812.5mg was received by patients and they had a median platelet increment of 36,000/cmm. We observed that there were no adverse effects in these patients and there was a gradual increase in platelet count so that none of the patients had any complication due to thrombocytopenia. The cost of treatment was less than the cost of extended hospitalization and irradiated single donor platelet transfusion.

Continuous Platelet Transfusion Increases Platelet Increment in Refractory Hemato-Oncological Patients – a Single Center Experience

▪Background: Refractoriness to platelet transfusion is prevalent among 15-25% of hemato-oncology patients. Refractoriness has been linked to inferior clinical outcomes, including bleeding and mortality, as well as higher health care costs. Suggested etiologies to refractoriness include both non-immune and immune causes. Methods to manage refractoriness include leuko-reduction, HLA- and HPA- matched platelets, use of ABO compatible transfusions and platelet cross-matching. Leuko-reduction has been proven to decrease the rates of allo-immunization and is widely used in hemato-oncology units. Other methods have demonstrated modest effectiveness in some studies, but some of these (HLA- and HPA- matched platelets) are not widely available. There are only a few reports in the literature of continuous platelet transfusion (CPT) as an alternative method for increasing post-transfusion platelet increments. Those reports prompted the current analysis of CPT in platelet refractory patients.Aim: To evaluate the effectiveness of CPT in producing satisfactory platelet increments in refractory patients compared to the standard care of routinely prepared single donor platelet transfusions.Patients and Methods: Patients included in this study were treated for hematological malignancies in our Institution between January 2007 and December 2013. A retrospective analysis of the increment of platelets achieved in refractory patients was performed. Refractoriness was defined as a corrected calculated increment (CCI) less than 10,000 platelets per micro-liter following two successive platelet transfusions. The CCI was calculated as PPI (post-transfusion platelet count minus pre-transfusion platelet count) x BSA (body surface area measured in square meters m2) x 1011/number of platelets transfused. All refractory patients included in this analysis received single donor platelet transfusions. The practice of CPT was adopted by us in March 2008. All refractory patients who received CPT between March 2008 and December 2013 were included. These patients received a continuous 24 hour transfusion of single donor platelet units, each dose given over 4 to 6 hours, comprising of 1.5 x 1011 platelets and equaling to half a single donor platelet unit. Their outcome was compared with that of our refractory patients treated with single donor transfusions in the routine manner, between January 2007 and March 2008 (i.e. before the introduction of CPT). The CCI was used to monitor the effectiveness of each platelet unit at 12 and 24 hours post-transfusion intervals. To account for prior antigen-exposure of the patients, we chose to include for each patient the 11th consecutive platelet transfusion. Factors known to contribute to the development of refractoriness, such as infection, disseminated intravascular coagulation (DIC) and splenomegaly were evaluated for impact on the CCI. The statistical analysis was generated using SAS Software, Version 9.4. Continuous variables were presented as mean ± STD, Categorical variables were presented by (N, %). t-tests and non-parametric Wilcoxon tests were used to compare the value of continuous variables between study groups.Results: Twenty eight patients with hematologic malignancies received at least eleven single-donor platelet transfusions during 2007-2013. Twenty one of the 28 patients received CPT due to refractoriness and seven patients were treated before the introduction of this approach. CPT resulted in a significantly higher post-transfusion mean increment at 24 hours (1.16 vs. 0.37, p<0.05). Increments were higher, albeit not significantly, at 12 hours post-transfusion in the CPT group (2.45 vs. 0.36, p=0.058). Patient’s gender, age (younger than 35 years old versus older), renal failure, high grade fever, infection and DIC, splenomegaly or donor-recipient ABO compatibility were not found to significantly influence the increment.Conclusions: CPT results in significantly higher increments at 24 hours post-transfusion, and therefore suggest an effective approach to the treatment of platelet refractoriness in patients treated for hematological malignancies. DisclosuresNo relevant conflicts of interest to declare.

Curious association between Plasmodium vivax malaria and nontraumatic acute subdural hematoma.

Sir, A 65-year-old male was brought to the erectile dysfunction with acute onset of altered consciousness level. Relatives informed that the patient was having high-grade fever 4 days back that lasted for 2 days. On the day of admission, the patient suddenly lost his consciousness following an episode of vomiting. Relatives denied any history of abnormal limb movements or frothing from mouth or any facial deviation. Repeated questioning of all the available relatives was negative for history of head trauma (even trivial). On examination, he was afebrile with heart rate 76/min, regular, blood pressure 130/80 mmHg. He was stuporous, Glasgow coma scale-E1 M5 V1 with bilateral equal size (2 mm) pupils reacting to light. There was a paucity of movement in the right side with right-sided extensor plantar reflex. There was no hepatosplenomegaly. Respiratory, cardiovascular, and skin examinations were unremarkable. Computed tomography head showed acute subdural hematoma involving left cerebral convexity with 7 mm midline shift [Figures ​[Figures11 and ​and2].2]. Laboratory investigations revealed leukopenia (3400/mm3) with normal differential count, thrombocytopenia (25,000/mm3) with normal hemoglobin level. Blood urea nitrogen and serum creatinine level were mildly elevated (41 and 1.6 mg/dl, respectively). Liver function test, electrocardiography, and chest X-ray did not reveal any abnormality. Peripheral blood film (both thick and thin film) showed Plasmodium vivax trophozoites. Rapid test for malaria (lactate dehydrogenase based antigen detection test, First sign) was also positive for P. vivax. Dengue serology (NS1, IgG, and IgM dengue) was negative. Patient was intubated and placed on mechanical ventilation. He was started on intravenous artesunate and clindamycin as per WHO guideline and was planned for decompressive craniotomy following platelet transfusion. Only the following day, the patient could be taken up for surgery following eight random donor and one single donor platelet transfusion. Left frontotemporoparietal craniotomy, evacuation of the hematoma and cranioplasty was done [Figure 2]. In the following days in the intensive care unit patient's blood film became negative for malaria parasites and platelet count normalized. However, his sensorium never showed improvement-he remained comatose throughout the postoperative course. On day 16 the family decided to take him home against medical advice. Figure 1 Acute subdural hematoma over left cerebral convexity Figure 2 Postcraniotomy Increasing number of severe manifestations reported in the literature contributed to the increasing interest in P. vivax infection recently. In an observational study of 40 cases of severe vivax malaria, Kochar et al., described different complications, including ARDS, acute kidney injury, thrombocytopenia, hepatic dysfunction, and cerebral malaria.[1] Mixed infection with Plasmodium falciparum species was ruled out by PCR method in all these cases. Falciparum malaria complicated by subdural hematoma has been described in the literature.[2,3] All these cases had associated thrombocytopenia. To the best of my knowledge, this is the first case reported in the literature of a case of vivax malaria associated with acute nontraumatic subdural hematoma.

Experience of buffy coat pooling of platelets as a supportive care in thrombocytopenic dengue patients: A prospective study.

Random donor platelet (RDP) is not sufficient to improve the platelet count in most thrombocytopenic patients. Single donor platelet (SDP) or buffy coat pooled platelet (BCPP) are the two choices to provide a full therapeutic dose of platelets. However, there are constraints in the preparation of SDP due to stringent donor selection procedure, time required for procedure, and need of special expensive equipments and kits. BCPP is widely practiced, especially in the European countries, since 1995. In India, we decided to adopt the procedure of buffy coat pooling of platelets, especially for economically backward patients and for emergencies. This study was prospectively conducted from September 2009 to September 2010. A total of 129 units of BCPP [tested prior for viral markers by enzyme-linked immunosorbent assay (ELISA) and individual donor nucleic acid amplification test (ID-NAT)] were issued to 129 patients suffering from dengue and were included in this study. For comparison between efficacy of SDP and BCCP, patients were divided into two groups of 50 each. The post-transfusion platelet counts of the patients were noted after 2 hours of transfusion for each type of component. The platelet yield varied from 2.5 to 4.4 Χ 1011 in BCPP samples. The samples analyzed were sterile without any contamination. The different biochemical parameters were analyzed in detail. The observed post-transfusion platelet recovery and corrected count increment (CCI) at 1 hour and 24 hours after BCPP transfusion were similar to that after SDP transfusion. Hence, we concluded that BCPP can be a low cost alternative to SDP in the times of emergencies like dengue and non-affordability by the patient for SDP.

Cross-match-compatible platelets improve corrected count increments in patients who are refractory to randomly selected platelets.

Cross-match-compatible platelets are used for the management of thrombocytopenic patients who are refractory to transfusions of randomly selected platelets. Data supporting the effectiveness of platelets that are compatible according to cross-matching with a modified antigen capture enzyme-linked immunosorbent assay (MAC-ELISA or MACE) are limited. This study aimed to determine the effectiveness of cross-match-compatible platelets in an unselected group of refractory patients. One hundred ABO compatible single donor platelet transfusions given to 31 refractory patients were studied. Patients were defined to be refractory if their 24-hour corrected count increment (CCI) was <5×10(9)/L following two consecutive platelet transfusions. Platelets were cross-matched by MACE and the CCI was determined to monitor the effectiveness of platelet transfusions. The clinical sensitivity, specificity, positive predictive value and negative predictive value of the MACE-cross-matched platelets for post-transfusion CCI were 88%, 54.6%, 39.3% and 93.2%, respectively. The difference between adequate and inadequate post-transfusion 24-hour CCI for MACE cross-matched-compatible vs incompatible single donor platelet transfusions was statistically significant (p=0.000). The 24-hour CCI (mean±SD) was significantly higher for cross-match-compatible platelets (9,250±026.6) than for incompatible ones (6,757.94±2,656.5) (p<0.0001). Most of the incompatible cross-matches (73.2%) were due to anti-HLA antibodies, alone (55.3% of cases) or together with anti-platelet glycoprotein antibodies (17.9%). The clinical sensitivity and negative predictive value of platelet cross-matching by MACE were high in this study and such tests may, therefore, be used to select compatible platelets for refractory patients. A high negative predictive value demonstrates the greater chance of an adequate response with cross-matched-compatible platelets.