جستجوی مقالات مرتبط با کلیدواژه « platelet transfusion » در نشریات گروه « پزشکی »

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.

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.

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).

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.

Although cold storage of platelets (PLTs) could decrease the risk of bacterial growth, it could affect on the PLTs viability and hemostatic function. At cold temperatures, trehalose can be used to substitute water, inhibit the solid-liquid transition phase of the PLT membrane, and stop Glycoprotein Ibα (GPIbα) polymerization. In this study, we evaluated the potential of trehalose for reducing the negative effects of cold storage on the apoptosis and the clearance rates of PLTs after long-term storage at cold.

Materials And Methods:

In this experimental study, PLT concentrates (PCs) were maintained for five days in the different circumstances. PLTs were subsequently counted by using an automated hematology analyzer. Also water-soluble tetrazolium salt (WST-1) assay was performed to estimate the viability of PLTs. The activity of lactate dehydrogenase enzyme (LDH) was determined by a biochemical analyzer. And human active caspase-3 levels were measured by using enzyme-linked immunosorbent assay (ELISA) method. Also, we applied flow cytometry technique.

PLTs count and viability were higher, while LDH amount was lower in trehalose-treated PLTs when compared with two other groups (P=0.03). The highest increase in the amount of caspase-3 levels in the PLTs was observed at 4°C. However, trehalose-treated and 4°C PLTs had a lower amount of active caspase-3 in comparison with 4°C PLTs. The level of PS expression on PLTs was lower in the trehalose-treated PLTs in compared with the two other groups (P=0.03). PLTs ingestion by HepG2 cells was enhanced in the 4°C-stored PLTs. However, the ingestion rate was significantly reduced in the trehalose-treated PLTs on day 5 of storage (P=0.03).

Trehalose can moderate the effects of cold temperature on the apoptosis, viability, and the survival rate of PLTs. It also decreases the ingestion rate of refrigerated PLTs in vitro.

All cells encounter various signals coming from the surrounding environment and they need to receive and respond to these signals in order to perform their functions. Cell surface receptors are responsible for signal transduction .Platelets are blood cells which perform several functions using diverse receptors. Platelet concentrate is one of the most consumed blood products. However, due to the short lifespan of the platelets and platelets damage during storage, we face shortage of platelet products. One of the damages that platelets undergo during storage is the loss of surface receptors. Since cell surface receptors are responsible for all cell functions, the loss of platelet receptors reduces the quality of platelet products. In this study, we reviewed the important receptors involved in platelet activation and their associated signaling pathways. We also looked at the platelet receptors that shed during storage and the causes of this incident. We found that GPIbα, P-selectin, CD40 and GPVI are platelet receptors that fall during platelet storage at room temperature. Considering that GPVI and GPIbα are the most important receptors which involved in platelet activation, their shedding can cause decrease in platelet activation after transfusion and decrease thrombus consistence. Shear stress and platelet contact with the container wall are among the mechanisms discussed in this process, but studies in this area have to be continued.

Androgenetic alopecia is the main cause of hair loss and common baldness that affects psychological more than physiological aspects of people’s lives. Studies have shown that this multi factorial disorder is initiated by androgens secretion in pubertal period, minerals limitations, autoimmunity, mental stress, genetic predisposition and some alterations in hematological factors.
The aim of this study was to evaluate the involvement of hematologic parameters in this disease using a case control study design.
In this case-controlled study, two groups each of 80 individuals with androgenetic alopecia were voluntarily included in the study based on their medical histories and clinical examinations and subjected to blood tests for routine hematological parameters. The results were then compared and analyzed using SPSS version 16.0.
Our findings indicated that all the parameters for both groups fall in normal ranges (Mean ± SD) but the values for RBC, HGB, MCH, MCHC, WBC, LYM and TIBC were significantly higher in patients than in normal group. The average counts of PLT was significantly lower in patients compared with the normal group. Otherwise, Person’s tests for statistical correlations between two groups indicated that the pattern of correlations were abnormal in patients.
Our findings indicated the presence of a chronic, immunologic and slowly progressing disorder that causes hair loss, the disease which is in turn triggered in pubertal period upon androgen secretion. We suggest, therefore, that the conditions may be ameliorated by prescription of iron tablet, platelet transfusion and anti-inflammation therapy.

This study was designed to evaluate platelet transfusion outcome via flow cytometric monocyte phagocytic assay (FMPA).
Fifteen patients with a history of multiple platelet transfusions and fifteen controls were enrolled in this study. CMFDA-labeled platelets were incubated with patient's sera and were finally incubated with monocytes in a tube and analyzed by flow cytometry. Monocytes that phagocytosed platelets were detected as a CMFDA-positive platelet population via monocyte gate. The FMPA results were compared with CCI results for the patients.
The FMPA result correlated with 1-hour (r = -0.885, P = 0.001) and 24-hour (r = -0.884, P = 0.001) CCI. There is a significant difference in means of FMPA results between the patients with immune platelet refractoriness (68.46 ± 10.4%), non-refractory group (37.73 ± 15.21%) and the control group (18.27 ± 2.86%).
Our data showed that FMPA has good results in evaluation of platelet transfusion outcome and may be useful as an indicator of platelet transfusion response.