Incubation of platelet concentrates before transfusion does not improve posttransfusion recovery M.A. HUSSEIN,C.A. SCHIFFER, AND E.J. LEE Incubation of stored platelet concentrates (PCs) a t 37°C for 1 hour h a s been reported to result in a better morphology score and improved platelet recovery. A study was conducted in adult patients with leukemia to determine whether incubation of stored PCs results in an improved platelet recovery as measured by 10-minute posttransfusion corrected count increments (CCI). Eligible patients had platelet counts of less than 30,000 per pL and were clinically stable. Patients were transfused with 6 to 1 0 units of PC stored for 3 days (15 studies) or 4 days (5 studies). Platelets were pooled and then split in two equal volumes so that each patient received two se uential halftransfusions, one incubated at 37°C for 1 hour and the other kept at 22% for 1 hour. Patients were randomized as to which half-transfusion was received first. The mean CCI of the incubated half-transfusions was 13.6 x lo3 when they were given first and 14.5 x 1O3 when given second: this was not significantly different from the mean CCI of the nonincubated half-transfusions: 13.8 x 1O3 when they were given first and 13.8 x 1O3 when given second. In contrast to earlier reports, it can be concluded that incubation of pooled PCs does not improve platelet recovery. TRANSFUSION 1990;30:701-703.
THE ADMINISTRATION OF PLATELET transfusions to patients with amegakaryocytic thrombocytopenia has resulted in a reduction of the morbidity and mortality associated with hemorrhage.'.* Platelet concentrates (PCs) are obtained as a by-product of whole blood donation from random donors and can currently be stored at 20 to 22°C for 1 to 5 days.3 However, prolonged storage has a somewhat detrimental effect on platelet r e c o v e ~ y . ~ Maneuvers that could enhance in vivo platelet recovery and survival of stored platelets might reduce the number of units required to support a given A recent in vitro study conducted by Garcez et al.' reported that the incubation of stored platelets at 37°C for 1 hour resulted in better morphology scores and retention of the normal disc shape by a higher fraction of those platelets than were seen in platelets that had not been incubated. Subsequently, a report by Hutchison4 suggested that the administration of incubated, stored platelets to children with amegakaryocytic thrombocytopenia is associated with an improvement in platelet recovery, as measured by a 2-hour posttransfusion platelet count, over that seen after paired transfusions prepared identically but without incubation. W e have conducted a study to determine if the apparent improvements in the quality of stored platelets From thc Division of Hematologic Malignancies, University of Maryland Canccr Center, and the Division of Hematology, Dcpartment of Medicine, University of Maryland School of Medicine, Baltimore, Maryland. Supported in part by a grant from Cutter Biological. Received for publication February 5, 1990; revision reccived April 17, 1990, and accepted April 19, 1990.
70 1
noted in vitro translate into improved platelet recovery in transfused adults.
Materials and Methods Eligible patients had amegakaryocytic thrombocytopenia with platelet counts of less than 30,000 per pL and were clinically stable. Stability was defined by a temperature < 101°F and no evidence o f . sepsis, coagulopathy, hemorrhage, or palpable splenomegaly. Alloimmunized patients requiring HLA-matched single-donor platelet transfusions were excluded. The Chesapeake Regional Red Cross staff collected platelets from 10 donors into storage bags (CLX, Cutter Biological, West Haven, CT). Platelets were stored as single PCs at 22°C with horizontal to-and-fro agitation for 3 days (15 studies) or 4 days (5 studies). Each patient received a mean of 400 mL of PC, representing 6 to 10 units of PC. On the day of transfusion, the platelets were pooled and then split in two equal volumes so that each patient would receive two half-transfusions in a single clinic visit. Patients were randomized to receive platelets incubated at 37°C or maintained at 22°C as their initial half-transfusion. When a patient was randomized to receive the incubated half-transfusion first, one half-pool was incubated at 37°C for 1 hour before transfusion and the other half-pool was maintained at 22°C without agitation. When the first half-transfusion was not incubated at 37"C, both half-pools were held for 1 hour at 22°C to allow for the same transfusion timing. The initial half-transfusion was administered in a period of 20 minutes. Ten minutes after its completion, a platelet count was obtained.h Thirty minutes later, the second halftransfusion was given in a period of 20 minutes. A posttransfusion platelet count was obtained 10 minutes later to complete the study. The platelet count 10 minutes after the first halftransfusion was used as the pretransfusion count for the second half-transfusion. Specimens were obtained from each half-pool for platelet counts. We measured all platelet counts on an automated cell counter (ELT-15, Ortho Instruments, Boston, MA).
702
As in previous ~ t u d i e s ,results ~ were expressed as corrected count increments (CCI)where
CCI
TRANSFUSION
HUSSEIN, SCHIFFER, AND LEE
=
absolute increment x body surface area (m’) number of platelets transfused x 10”
.
Results We studied 20 transfusions to 17 clinically stable adult patients. Three transfusions given to three patients were inevaluable. One patient received an inadequate number of platelets. A second patient did not achieve a good increment with either half-transfusion and was found to have a high level of lymphocytoxic antibody; he responded well on the day after the study transfusions to a transfusion from an HLA-matched donor. The specimen obtained from the third of these patients for the platelet count 10 minutes after the second half-transfusion clotted. Therefore, 17 transfusions to 14 patients were evaluable. Data from these procedures are summarized in Table 1. Patients randomized to receive incubated platelets (37°C)as their first half-transfusion had a mean CCI of 13.6 x lo3with the incubated platelets and a mean CCI of 13.8 x lo3 with nonincubated platelets. Patients who were randomized to receive nonincubated platelets first had a mean CCI of 14.5 X lo3 with the incubated platelets and a mean CCI of 13.8 x lo3 with the nonincubated platelets. The mean CCI for all transfusions incubated at 37°C was 14.0 x lo3 and for all transfusions maintained at 22°C was 13.8 x lo3 (p=O.88 by paired t test). These increments are comparable to the mean CCI of 13.6 x lo3, reported earlier by our group,3 in nonsplenectomized patients given a large number of transfusions of platelets stored for 3 days.
Discussion Methods to improve the posttransfusion recovery of stored PCs would be welcomed as a means of decreasing transfusion frequency in patients requiring repeated transfusions. However, we did not find a significant difference between the mean CCIs following the transfusion of incubated and nonincubated PCs. We used a study design in which the original pool of platelets was split, thereby eliminating possible influences of differences in initial preparation and storage, donor source,
Vol. 30. No. 8-1990
and changes in the patients’ condition. The results were identical whether the incubated half-transfusion was given first or second. Our results differ from those of Hutchison et aL4 who studied 15 patients and found that the CCIs following the transfusion of incubated pooled PCs were greater than the CCIs following the transfusion of nonincubated PCs, particularly when the incubated PCs were given first. In the Hutchison article, when statistical methods were used that included linear regression analysis after adjustment for the order in which the transfusions were used, the significance was even more pronounced. There were several differences between the study design and technique of our studies and those of Hutchison et al. In our study, we used the 10-minute posttransfusion platelet count to calculate the CCI, whereas in the earlier study, 1- and 2-hour posttransfusion platelet counts were used. Because there is a close relationship between 10- and 60-minute posttransfusion counts, however, this is an unlikely explanation for the discrepant conclusions.6 The half-transfusion administered last in our study remained as a pool for 2 hours before transfusion, whereas in the earlier study, which required 2-hour posttransfusion platelet counts, a delay of at least 3.5 hours was required between pooling and transfusion. In the article by Hutchison et al., no information was given as to whether agitation was maintained during the period of time between pooling and transfusion. This prolonged period, during which a large volume of platelets occupied a relatively small space, possibly without agitation, may have induced some damage to the pooled platelets. It must be noted, however, that the CCIs they reported with the incubated platelets were almost the same regardless of the order of transfusion (mean CCIs of 17.9 and 18.6 x lo3); similar results were seen with the nonincubated platelets (CCIs of 13.4 and 14.9 x lo3) and in our study as well (Table 1). There were also differences in the methods and possibly the duration of platelet storage prior to pooling. In our study, transfused platelets were stored for 3 to 4
Table 1. Response to transfusion of platelets incubated a t 37 or 22°C before transfusion
Procedure
Incubation temperature
Number of transfusions
Number of transfused patients
37°C 22°C 37°C
17 17 9
14 14 8
14.0 -t 8.5 13.8 f 6.8 13.6 2 9.7
22°C 37°C
8 8
13.8 ? 7.7 14.5 2 7.5
22°C
8
13.8 ? 6.1
Evaluable transfusions Platelets incubated at 37°C given first
103)
SD
p values NSt NS
Platelets incubated at 22°C given first
NS
Corrected count increment.
t Not significant (by paired
Mean CCP (X
t test).
TRANSFUSION 1990-VoI. 30, No. 8
703
INCUBATION AND PLATELET RECOVERY
days after to-and-fro agitation, whereas the duration of storage used by Hutchison et al. was not specified, and a rotary agitator was used. Another technical difference is that our adult patients received an average volume of 200 mL per half-transfusion, whereas Hutchison’s pediatric patients, who had a mean age of 9 years, received a total of 4 units per mz. Therefore, these pediatric patients received approximately one-half the volume our patients received. It is possible, although less likely, that the improvement in morphology scores seen by both Garcez and Hutchison and their coworkers reflects a more efficient warming process in smaller volumes than that achieved in the larger pools intended for adults. Thus, there is no clearcut explanation for the differences in results. Although relatively simple, the incubation procedure used in these two studies represents an increase in the complexity of current blood banking procedures and carries a chance, albeit modest, for bacterial contamination. On the basis of our results, we would not recommend the incubation of platelets before transfusion. The experimental design used in these studies does represent a simple and efficient means of assessing the immediate posttransfusion effectiveness of pretransfusion manipulations of platelet products.
References 1. Higby DJ, Cohen E, Holland JF, Sinks L. The prophylactic trcatment of thrombocytopenic leukemic patients wifh platclcts: a dou-
blc blind study. Transfusion 1974;14:440-6. 2. Schiffer CA, Aisner J, Wiernik PH. Platelet transfusion therapy for patients with leukemia. In: Greenwalt TJ,Jamicson GA, eds. The blood plafelet in transfusion therapy. New York: Alan R Liss, 1978:267-79. 3. Schiffer CA,Lce ET, Ness PM, Reilly J. Clinical evaluation of platelef concentrates stored for one to five days. Blwd 1986;67:1591-4. 4. Hutchison RE, Schell MJ, Nelson EJ, et al. Beneficial effect of brief pre-transfusion incubation of platelets at 37°C. Lancet 1989;1:986-8. 5 . Garcez R, Champion A, Stambolija L, Carmen R. Pla~elctimprovements in vitro due to one hour incubation at 37’C (abstract). Transfusion 1987;27:509. 6. O’Connell B, Lce EJ, Schiffer CA. The value of 10-minute posttransfusion platelet counts. Transfusion 1988;28:66-7. Mohamad A. Hussein, MD, Assistant Professor of Medicine and Oncology, Department of Medicine, University of Maryland Hospital, University of Maryland Cancer Ccntcr, 22 South Greene Strcct, Baltimore, MD 21201. [Reprint requests] Charles A. Schiffer, MD, Professor of Medicine and Oncology and Head of Hematologic Malignancies, University of Maryland Cancer Center, and Chief, Division of Hematology, School of Medicine, University of Maryland Hospital, Baltimore, MD. Edward J. Lee, MD, Associate Professor of Medicine and Oncology, Department of Medicine, University of Maryland Hospital, University of Maryland Cancer Center.
Announcement SYMPOSIUM ON THE CELLULAR AND MOLECULAR BASIS OF THE PLATELET STORAGE LESION The symposium on the cellular and molecular basis of the platelet storage lesion, organized by the Yale University School of Medicine and sponsored by the National Heart, Lung, and Blood Institute and the American Association of Blood Banks, and held April 9-10, 1991 in Bethesda, Maryland is designed to stimulate investigator-initiated research which will address fundamental questions concerning the etiology of the platelet storage lesion. A major goal is to provide a forum for platelet researchers in transfusion medicine, hematology and basic science to interact and share new ideas. The symposium will provide a review, by recognized leaders in the field, of various aspects of the cellular and molecular changes which occur in platelets during blood bank storage as well as in vivo, during activation. The content of the meeting will be at the intermediate to advanced level and there will be numerous opportunities for discussion and interaction among attendees. A consensus panel will convene on April 10, 1991 to summarize symposium highlights, discuss and expand on areas covered during the meeting and to identify, formulate, and recommend future research directions and initiatives. For registration information contact: The Office of Postgraduate and Continuing Medical Education Yale University School of Medicine Room IE-53 SHM 333 Cedar Street New Haven, CT 06510 (203) 785-4578
THE ADMINISTRATION OF PLATELET transfusions to patients with amegakaryocytic thrombocytopenia has resulted in a reduction of the morbidity and mortality associated with hemorrhage.'.* Platelet concentrates (PCs) are obtained as a by-product of whole blood donation from random donors and can currently be stored at 20 to 22°C for 1 to 5 days.3 However, prolonged storage has a somewhat detrimental effect on platelet r e c o v e ~ y . ~ Maneuvers that could enhance in vivo platelet recovery and survival of stored platelets might reduce the number of units required to support a given A recent in vitro study conducted by Garcez et al.' reported that the incubation of stored platelets at 37°C for 1 hour resulted in better morphology scores and retention of the normal disc shape by a higher fraction of those platelets than were seen in platelets that had not been incubated. Subsequently, a report by Hutchison4 suggested that the administration of incubated, stored platelets to children with amegakaryocytic thrombocytopenia is associated with an improvement in platelet recovery, as measured by a 2-hour posttransfusion platelet count, over that seen after paired transfusions prepared identically but without incubation. W e have conducted a study to determine if the apparent improvements in the quality of stored platelets From thc Division of Hematologic Malignancies, University of Maryland Canccr Center, and the Division of Hematology, Dcpartment of Medicine, University of Maryland School of Medicine, Baltimore, Maryland. Supported in part by a grant from Cutter Biological. Received for publication February 5, 1990; revision reccived April 17, 1990, and accepted April 19, 1990.
70 1
noted in vitro translate into improved platelet recovery in transfused adults.
Materials and Methods Eligible patients had amegakaryocytic thrombocytopenia with platelet counts of less than 30,000 per pL and were clinically stable. Stability was defined by a temperature < 101°F and no evidence o f . sepsis, coagulopathy, hemorrhage, or palpable splenomegaly. Alloimmunized patients requiring HLA-matched single-donor platelet transfusions were excluded. The Chesapeake Regional Red Cross staff collected platelets from 10 donors into storage bags (CLX, Cutter Biological, West Haven, CT). Platelets were stored as single PCs at 22°C with horizontal to-and-fro agitation for 3 days (15 studies) or 4 days (5 studies). Each patient received a mean of 400 mL of PC, representing 6 to 10 units of PC. On the day of transfusion, the platelets were pooled and then split in two equal volumes so that each patient would receive two half-transfusions in a single clinic visit. Patients were randomized to receive platelets incubated at 37°C or maintained at 22°C as their initial half-transfusion. When a patient was randomized to receive the incubated half-transfusion first, one half-pool was incubated at 37°C for 1 hour before transfusion and the other half-pool was maintained at 22°C without agitation. When the first half-transfusion was not incubated at 37"C, both half-pools were held for 1 hour at 22°C to allow for the same transfusion timing. The initial half-transfusion was administered in a period of 20 minutes. Ten minutes after its completion, a platelet count was obtained.h Thirty minutes later, the second halftransfusion was given in a period of 20 minutes. A posttransfusion platelet count was obtained 10 minutes later to complete the study. The platelet count 10 minutes after the first halftransfusion was used as the pretransfusion count for the second half-transfusion. Specimens were obtained from each half-pool for platelet counts. We measured all platelet counts on an automated cell counter (ELT-15, Ortho Instruments, Boston, MA).
702
As in previous ~ t u d i e s ,results ~ were expressed as corrected count increments (CCI)where
CCI
TRANSFUSION
HUSSEIN, SCHIFFER, AND LEE
=
absolute increment x body surface area (m’) number of platelets transfused x 10”
.
Results We studied 20 transfusions to 17 clinically stable adult patients. Three transfusions given to three patients were inevaluable. One patient received an inadequate number of platelets. A second patient did not achieve a good increment with either half-transfusion and was found to have a high level of lymphocytoxic antibody; he responded well on the day after the study transfusions to a transfusion from an HLA-matched donor. The specimen obtained from the third of these patients for the platelet count 10 minutes after the second half-transfusion clotted. Therefore, 17 transfusions to 14 patients were evaluable. Data from these procedures are summarized in Table 1. Patients randomized to receive incubated platelets (37°C)as their first half-transfusion had a mean CCI of 13.6 x lo3with the incubated platelets and a mean CCI of 13.8 x lo3 with nonincubated platelets. Patients who were randomized to receive nonincubated platelets first had a mean CCI of 14.5 X lo3 with the incubated platelets and a mean CCI of 13.8 x lo3 with the nonincubated platelets. The mean CCI for all transfusions incubated at 37°C was 14.0 x lo3 and for all transfusions maintained at 22°C was 13.8 x lo3 (p=O.88 by paired t test). These increments are comparable to the mean CCI of 13.6 x lo3, reported earlier by our group,3 in nonsplenectomized patients given a large number of transfusions of platelets stored for 3 days.
Discussion Methods to improve the posttransfusion recovery of stored PCs would be welcomed as a means of decreasing transfusion frequency in patients requiring repeated transfusions. However, we did not find a significant difference between the mean CCIs following the transfusion of incubated and nonincubated PCs. We used a study design in which the original pool of platelets was split, thereby eliminating possible influences of differences in initial preparation and storage, donor source,
Vol. 30. No. 8-1990
and changes in the patients’ condition. The results were identical whether the incubated half-transfusion was given first or second. Our results differ from those of Hutchison et aL4 who studied 15 patients and found that the CCIs following the transfusion of incubated pooled PCs were greater than the CCIs following the transfusion of nonincubated PCs, particularly when the incubated PCs were given first. In the Hutchison article, when statistical methods were used that included linear regression analysis after adjustment for the order in which the transfusions were used, the significance was even more pronounced. There were several differences between the study design and technique of our studies and those of Hutchison et al. In our study, we used the 10-minute posttransfusion platelet count to calculate the CCI, whereas in the earlier study, 1- and 2-hour posttransfusion platelet counts were used. Because there is a close relationship between 10- and 60-minute posttransfusion counts, however, this is an unlikely explanation for the discrepant conclusions.6 The half-transfusion administered last in our study remained as a pool for 2 hours before transfusion, whereas in the earlier study, which required 2-hour posttransfusion platelet counts, a delay of at least 3.5 hours was required between pooling and transfusion. In the article by Hutchison et al., no information was given as to whether agitation was maintained during the period of time between pooling and transfusion. This prolonged period, during which a large volume of platelets occupied a relatively small space, possibly without agitation, may have induced some damage to the pooled platelets. It must be noted, however, that the CCIs they reported with the incubated platelets were almost the same regardless of the order of transfusion (mean CCIs of 17.9 and 18.6 x lo3); similar results were seen with the nonincubated platelets (CCIs of 13.4 and 14.9 x lo3) and in our study as well (Table 1). There were also differences in the methods and possibly the duration of platelet storage prior to pooling. In our study, transfused platelets were stored for 3 to 4
Table 1. Response to transfusion of platelets incubated a t 37 or 22°C before transfusion
Procedure
Incubation temperature
Number of transfusions
Number of transfused patients
37°C 22°C 37°C
17 17 9
14 14 8
14.0 -t 8.5 13.8 f 6.8 13.6 2 9.7
22°C 37°C
8 8
13.8 ? 7.7 14.5 2 7.5
22°C
8
13.8 ? 6.1
Evaluable transfusions Platelets incubated at 37°C given first
103)
SD
p values NSt NS
Platelets incubated at 22°C given first
NS
Corrected count increment.
t Not significant (by paired
Mean CCP (X
t test).
TRANSFUSION 1990-VoI. 30, No. 8
703
INCUBATION AND PLATELET RECOVERY
days after to-and-fro agitation, whereas the duration of storage used by Hutchison et al. was not specified, and a rotary agitator was used. Another technical difference is that our adult patients received an average volume of 200 mL per half-transfusion, whereas Hutchison’s pediatric patients, who had a mean age of 9 years, received a total of 4 units per mz. Therefore, these pediatric patients received approximately one-half the volume our patients received. It is possible, although less likely, that the improvement in morphology scores seen by both Garcez and Hutchison and their coworkers reflects a more efficient warming process in smaller volumes than that achieved in the larger pools intended for adults. Thus, there is no clearcut explanation for the differences in results. Although relatively simple, the incubation procedure used in these two studies represents an increase in the complexity of current blood banking procedures and carries a chance, albeit modest, for bacterial contamination. On the basis of our results, we would not recommend the incubation of platelets before transfusion. The experimental design used in these studies does represent a simple and efficient means of assessing the immediate posttransfusion effectiveness of pretransfusion manipulations of platelet products.
References 1. Higby DJ, Cohen E, Holland JF, Sinks L. The prophylactic trcatment of thrombocytopenic leukemic patients wifh platclcts: a dou-
blc blind study. Transfusion 1974;14:440-6. 2. Schiffer CA, Aisner J, Wiernik PH. Platelet transfusion therapy for patients with leukemia. In: Greenwalt TJ,Jamicson GA, eds. The blood plafelet in transfusion therapy. New York: Alan R Liss, 1978:267-79. 3. Schiffer CA,Lce ET, Ness PM, Reilly J. Clinical evaluation of platelef concentrates stored for one to five days. Blwd 1986;67:1591-4. 4. Hutchison RE, Schell MJ, Nelson EJ, et al. Beneficial effect of brief pre-transfusion incubation of platelets at 37°C. Lancet 1989;1:986-8. 5 . Garcez R, Champion A, Stambolija L, Carmen R. Pla~elctimprovements in vitro due to one hour incubation at 37’C (abstract). Transfusion 1987;27:509. 6. O’Connell B, Lce EJ, Schiffer CA. The value of 10-minute posttransfusion platelet counts. Transfusion 1988;28:66-7. Mohamad A. Hussein, MD, Assistant Professor of Medicine and Oncology, Department of Medicine, University of Maryland Hospital, University of Maryland Cancer Ccntcr, 22 South Greene Strcct, Baltimore, MD 21201. [Reprint requests] Charles A. Schiffer, MD, Professor of Medicine and Oncology and Head of Hematologic Malignancies, University of Maryland Cancer Center, and Chief, Division of Hematology, School of Medicine, University of Maryland Hospital, Baltimore, MD. Edward J. Lee, MD, Associate Professor of Medicine and Oncology, Department of Medicine, University of Maryland Hospital, University of Maryland Cancer Center.
Announcement SYMPOSIUM ON THE CELLULAR AND MOLECULAR BASIS OF THE PLATELET STORAGE LESION The symposium on the cellular and molecular basis of the platelet storage lesion, organized by the Yale University School of Medicine and sponsored by the National Heart, Lung, and Blood Institute and the American Association of Blood Banks, and held April 9-10, 1991 in Bethesda, Maryland is designed to stimulate investigator-initiated research which will address fundamental questions concerning the etiology of the platelet storage lesion. A major goal is to provide a forum for platelet researchers in transfusion medicine, hematology and basic science to interact and share new ideas. The symposium will provide a review, by recognized leaders in the field, of various aspects of the cellular and molecular changes which occur in platelets during blood bank storage as well as in vivo, during activation. The content of the meeting will be at the intermediate to advanced level and there will be numerous opportunities for discussion and interaction among attendees. A consensus panel will convene on April 10, 1991 to summarize symposium highlights, discuss and expand on areas covered during the meeting and to identify, formulate, and recommend future research directions and initiatives. For registration information contact: The Office of Postgraduate and Continuing Medical Education Yale University School of Medicine Room IE-53 SHM 333 Cedar Street New Haven, CT 06510 (203) 785-4578
