Platelet transfusions play a major role in preventing major haemorrhage and improve survival in severe thrombocytopenic patients [1]. Platelet units obtained by plateletpheresis are called SDP. The number of platelets in an apheresis product is equivalent to 6-10 random platelet concentrates and contains at least 3.0×1011 platelets [2]. Now-a-days, there is an increased demand for SDP than random donor platelets as they are associated with low risk of transfusion-transmitted diseases and also alloimmunization.
Generally, apheresis procedures are well tolerated. At times, adverse events of varying severity may occur during or after the procedure. These adverse events are divided into local and systemic reactions [3]. Local reactions are caused by the damage of blood vessel during phlebotomy procedure resulting in accumulation of blood outside the veins called as haematomas. These haematomas are associated with bruising, discolouration, local pain and swelling [3,4]. Systemic reactions are mainly vasovagal reactions that can be triggered by the pain of vein-puncture or by the anxiety and state of tension of undergoing the donation etc., [5]. These are characterised by the pallor, sweating, dizziness, nausea, hypotension and syncope. Citrate toxicity due to hypocalcaemia entails perioral paresthesia of the extremities, tremors, dizziness, chills, tetany and seizure [5]. As compared to whole blood donors, the SDP donors are far less and any adverse reaction in them will make the subsequent recruitment of the SDP donors difficult. The aim of this study was to identify the profile of platelet donors and the parameters of plateletpheresis procedure in correlation with the adverse events resulting from plateletpheresis donation.
Materials and Methods
This retrospective study was carried out from November 2014 to June 2018. Data was collected from the records maintained by the Department of IHBT in a tertiary care hospital in Southern India. A total of 615 SDP procedures were performed during study period. Both continuous and intermittent flow centrifugation cell separators (Fresenius Kabi and Trima Accel) were used for performing procedures. All donations were collected from peripheral venous access in the cubital fossa using 16 gauze needle, with required aseptic precautions. Donors were selected as per the SOP criteria for SDP procedure in accordance to our hospital protocol such as weight 60 kg or more, age between 18 to 60 years, Hb 12.5 g/dL and platelet count >1.5 lacs/dL.
As per Drugs and cosmetics act guidelines, if donors used aspirin containing medication within 36 hours were deferred. Interval between procedures should be at least 48 hours and not more than twice a week or 24 times in a year. All the donors were free from any illness and tested negative for HIV, Hep. B, HCV, Syphilis, and Malaria.
Statistical Analysis
Association between platelet count, ACD volume used for each procedure and citrate toxicity was studied by calculating “r”-value (Pearson correlation) using software Microsoft Excel 2007 and p-value by using paired t-test.
Results
A total of 615 plateletpheresis procedures were performed during the study period. All the donors were males. Age range of SDP donors varied from 19 years to 48 years. An 88.93% of donors were between 18 years to 35 years. Majority of the donors (529) were first-time donors and 41 donors were repeat donors [Table/Fig-1].
| Type of donors | No. (%) |
|---|
| First time donors | 529 (92.8%) |
| Repeat donors37 donors-donated twice 37*2=744 donors donated thrice 4*3=12 | 41 (7.2%) |
| Total donors (615 SDP procedures) | 570 |
Association between platelet count, ACD volume used for each procedure and citrate toxicity is shown in [Table/Fig-2]. Platelet counts of the donors ranged from 1.6 to 4.5 lacs/dL. Higher the platelet count of the donor before SDP procedure was associated with low ACD volume consumption, less duration of the procedure and reduced citrate toxicity reactions as shown in [Table/Fig-3]. Amongst the selected 615 procedures, a total of 25 (4.06%) donors had some type of adverse event, 15 (2.43%) had citrate related toxicity reactions, 2 (0.32%) had a vasovagal reactions, 8 (1.3%) had haematomas [Table/Fig-4]. Among the donors who suffered adverse events, 22 (88%) were first-time platelet donors and 3 (12%) were repeat donors. All the reactions were mild and well managed. Only one case had a severe reaction of convulsion (0.16%) during the end of the procedure and recovered immediately after removing the needle and elevating the foot end. Later on, the donor revealed that he had a seizure disorder during his childhood for which he took treatment 15 years back and was asymptomatic since then.
Pearson’s correlation between different parameters in SDP procedure.
| Parameter | Parameter | r-value | Interpretation | p-value |
|---|
| Donor platelet count | Donor reactions | -0.96 | Strong negative correlation | 0.001 |
| Donor platelet count | ACD volume consumed | -0.96 | Strong negative correlation | 0.001 |
| Donor platelet count | Duration of the procedure | -0.95 | Strong negative correlation | 0.001 |
| ACD volume consumed | Citrate toxicity | 0.99 | Strong positive correlation | 0.001 |
| Duration of the procedure | ACD volume consumed | 0.99 | Strong positive correlation | 0.001 |
SDP procedure details and occurence of adverse reactions.
| Platelet count lacs/dL | No. of SDP Donors | Percentage % | Duration | ACD consumption in mL | Donor reactions |
|---|
| 1.5-2.0 | 92 | 14.90 | 61-90 min | 300-400 | 9-Citrate toxicity2-Hematomas |
| 2.1-2.5 | 172 | 27.86 | 60 min | 250-300 | 4-Citrate toxicity2-Hematomas |
| 2.6-3.0 | 180 | 29.16 | 50 min | 231-260 | 2-Citrate toxicity2-Hematomas1-sweating |
| 3.1-3.5 | 95 | 15.39 | Under 45 min | 201-230 | 1-Hematoma1-Vomiting |
| 3.6-4.0 | 74 | 11.98 | Under 40 min | 180-200 | 1-Hematoma |
| 4.0-4.5 | 2 | 0.32 | Under 35 min | 170-180 | Nil |
| Total | 615 | 100 | | | 15-Citrate toxicity8-Hematomas2-others |
| Types | Reaction | No. |
|---|
| Citrate related toxicity causes | Peri-oral paresthesia | 12 |
| Convulsion | 1 |
| Muscle spam | 2 |
| Vaso-vagal causes | Vomiting | 1 |
| Sweating | 1 |
| Local causes | Hematomas (swelling, bruising, pain) | 8 |
| Total | 25 (4.06%) (Severe adverse reactions-0.16%) |
Discussion
The present study main focus was to identify the profile of platelet donors and the parameters of plateletpheresis donations as well as the adverse events resulting from plateletpheresis donation. Even though there is no evidence that these procedures are associated with severe complications, different reports from medical literature shows variation in the frequency of occurence of adverse events during the donation [6].
In the present study, majority of the donors were under the age of 35 years (88.93%) which was in agreement with the studies in literature [7-9]. However in a study by Barbosa MH et al., the predominant donor age range was 40-49 years [10].
In this study, total of 4.06% (25/570) donors had some kind of adverse events. Among them, 22 (88%) were first-time platelet donors and 3 (12%) were repeat donors. In a study by Arora D et al., 13 (3.48%) were first-time platelet donors and 2 (0.58%) were repeat donors among the 15 donors who had adverse event out of 344 donors [7]. The study by Crocco I et al., showed only 0.68% (18/2,641) which is a very low incidence of adverse events among the plateletpheresis donors as this study has not included the local reactions like haematomas as adverse events [6]. The study conducted by Patidar GK et al., had a very high incidence of adverse events of 18% (90/500) among the plateletpheresis donors [11].
It was observed that the lower the donor platelet count, the more were the occurence of citrate toxicity related adverse events among donors. This could be due to increased duration of procedure which results in increased infusion of ACD (anticoagulant) to the donor. A study revealed that adverse events occurred in plateletpheresis procedures which took more time (mean 77.1 min) compared to those without adverse events [12]. All the donors who had citrate related adverse events were first-time donors accounting for 2.43% (15/615). Citrate related adverse events in other studies conducted by Philip J et al., Crooco I et al., Patidar GK et al., and Khajuria K et al., were 0.96%, 0.38%, 9.0% and 3.03% respectively [5,6,11,13].
In the present study, one case of convulsion was observed which was a severe reaction and accounts for 0.16% (1/615). Further, this could have been prevented provided the donor had not concealed his past history of seizure disorder. Despotis GJ et al., reported 0.24% of severe adverse events in plateletpheresis donors [14].
Vasovagal reactions and haematomas have no relation to platelet count of donors or ACD consumed by the donors. There incidence in SDP donors may be similar to whole blood donors. In our study, the incidence of vasovagal reactions was 0.32% (2/615) among first-time donors which was in agreement with the study conducted by Reiss RF et al., [15], where the vasovagal reactions varied from 0.32% to 0.64% among different age groups. In a study conducted by Crocco I et al., the incidence of vasovagal reactions was 0.68% (18/2,641) [6].
In our study, local reactions like haematomas were observed in 1.3% (8/615), whereas it was 1.16% (4/344) and 1.51% (1/66) in a study by Arora D et al., and Khajuria K et al., respectively [7,13]. Tomita T et al., Observed difference between apheresis donors and whole blood donors in the incidence of vasovagal reactions increased with age for SDP and not same with the whole blood donations [16]. Formation of haematomas can be considered if there are any factors such as thin or deep veins in the venipuncture site, going through the vein by an under experienced nurse/technologist causing damage to the vessel or extravasation of red cells during return phase, improper care after the initial bleeding was stopped from venipuncture are associated with the formation of haematoma [10,17]. In this study, female SDP donors were not included, because the number of female donors coming for SDP donation is very less and all of them were deferred for not fitting in the selection criteria and in general for low haemoglobin. The studies in the literature also documented minimal female SDP donors [8].
Conclusion
The overall rate of acute adverse events, among healthy SDP donors in our study was very low. Citrate toxicity was reduced significantly in the donors with platelet count 2.5-4.5 lac/dL in our study. All the adverse events were managed very well. None required hospitalisation of the SDP donor. Vasovagal reactions could be managed easily similar to those occurring during whole blood donations. Vein puncture related local reactions can further be minimised to some extent by allowing only an experienced professional to perform the procedure. This low rate of mild adverse events in our study underlies safety of donors of plateletpheresis.