Amphotericin B and platelet transfusion

Platelet transfusions are being prescribed with ever- increasing frequency, yet the response in recipients is not optimal. On the basis of generally accepted physi- ologic principles, it can be estimated' that the transfusion of 1 unit (7.5 x 1O'O) of platelets should result in an increase in platelet count of 20,OOO per m3 in a recip- ient with 1 m2 body surface area. Thus, for each indi- vidual transfusion, one can calculate the corrected count increment (CCI)2

Measured count increase x bodv surface area fm2) ~~

Number of units transfused

to judge the efficacy of the transfusion. An increment of 20,000 per mm3 is anticipated in a patient with mar- row failure if the result is optimal.

Clinicians know that such a response is rare. Rather, the average CCI, 10,OOO per mm,3 is approximately one- half that expected, with variability in the range of 0 to 20,000 per mm3 in a large group of ~a t ien ts .~ Much research has been devoted to the phenomenon of alloim- munization to HLA antigens,' which accounts for 25 to 50 percent of the poor responses. There is evidence that reducing the level of contaminating white cells in red cell and platelet transfusions will reduce the incidence of this phenomenon. This proposition is currently being tested in a multi-institution trial in the United state^.^

However, there are other, less well defined factors that interfere with response to transfusion. In two recent studies, Bishop et al.3*6 attempted to identify and clarify the role of these factors by performing, in 133 patients with bone marrow failure, a prospective study of trans- fusion of platelets stored for up to 5 days. Not surpris- ingly, multiple linear regression analysis identified HLA antibody grade as a major factor negatively influencing posttransfusion increments, which confirmed the impor- tance of alloimmunization. Moreover, the analysis con- firmed previous work7 indicating that disseminated intravascular coagulation and splenomegaly also have a negative effect. On the other hand, it was new infor- mation that prior bone marrow transplantation and con- current administration of amphotericin B also had a negative effect, which was even stronger than the effect of HLA antibody grade. Since amphotericin B is so widely used in patients with bone marrow failure, its effect on the response to platelet transfusion stood out as an item worthy of further study.

Amphotericin B binds to membrane sterols of mam- malian cells, including those in the blood. After infusion in routine clinical doses, it increases the permeability of

the recipient's red cell membrane to cations." However, red cell survival is not compromised because healthy red cells can compensate by increasing their rate of cation pumping. Rather, the anemia that is observed during therapy with amphotericin B is due to bone marrow suppression. Over 10 years ago, Wright et al.9 described a group of patients who suffered severe, sometimes fatal respiratory deterioration after infusions of amphotericin B administered during the course of white cell transfu- sions. They speculated that alhphotericin B lysed aggre- gates of transfused white cells trapped in the microvasculature of the lung, permitting the release of neutrophil proteases that damaged pulmonary tissue. Al- though two other reportslOJ1 failed to confirm this as- sociation, one is still left with the thought that amphotericin B may damage transfused blood cells predisposed to this damage by previous in vitro manipulations in the blood center. Certainly, in vivo infusion of amphotericin B is not known to shorten the life span of healthy platelets and white cells circulating after formation in the bone marrow. If amphotericin B does bind with the mem- branes of these healthy cells, they appear to be able to compensate in a fashion similar to the red cells described above."

Of course, the findings of Bishop et al.3.6 are open to other interpretations. Myelosuppressed patients who re- ceive amphotericin B typically are leukopenic, and they remain febrile and toxic in spite of the administration of broad-spectrum antibacterial antibiotics. Thus, they are the sickest of a very sick group of patients. It is possible that the mere fact that amphotericin B is prescribed to a patient identifies him or her as one of a group of patients who are destined to respond poorly to platelet transfu- sions because of one or more components of the toxic state, such as deep tissue infection or widespread inflam- mation and endothelial damage.

Nonetheless, it is entirely appropriate that, as reported in this issue of TRANSFUSION, McGrath et al.12 have pursued their finding by studying the effect of ampho- tericin B on fresh and stored platelets in vitro. They describe "pits" on the surface membrane of platelets, which were in greatest numbers immediately after the preparation of platelet concentrates. The number of pits gradually decreased with storage. Exposure to ampho- tericin B increased the number of pits on stored platelets but had no effect on fresh platelets. The authors conclude that amphotericin B exacerbates a membrane lesion in- duced by preparation and storage of platelet concen- trates. It is difficult, however, to accept the concept that the pits represent a lesion that correlates directly with

7

8 EDITORIAL

platelet viability in vivo. There are as many pits on plate- lets in freshly prepared platelet concentrates that have not been exposed to amphotericin B as there are on plate- lets that have been stored for 5 days and then exposed to amphotericin B. Surely, the freshly prepared platelet concentrates would be more vikble after transfusion in vivo.

The authors do, however, raise a major point for con- sideration. There is no doubt that a platelet storage lesion exists. During storage, platelets lose, to some degree, their discoid shape and response to aggregating agents.13 Reduction in cellular ATP,13 vesiculation of procoagu- lant membranous microparticles," and alterations in membrane glycoprotein~'~J~ also occur. These changes have much in common with changes seen when platelets are activated by physiologic ag0ni~ts. l~ In spite of all these alterations, platelets stored for 5 days under opti- mal circumstances have only a 20-percent reduction in viability when assessed in vivo by either autologous transfusion studies in normal volunteerP or by trans- fusion into clinically stable (i.e., not sick) thrombocy- topenic patienk2 However, it has been suggested,4.lg though not adequately documented, that stored platelets circulate very poorly in some sick patients who would respond well to fresh platelets. According to this pro- posal, one or more components of the storage lesion interact synergistically with in vivo factors. Amphoter- icin B might be such a factor. In addition, stored plate- lets express an alpha-granule membrane protein (GMP- 140) on their surface, whereas fresh, unactivated platelets do not.lSJ6 GMP-140 can mediate the adhesion of plate- lets to granulocytes, monocytes, and other phagocytic cells.20 It may be that the phagocytic system of sick patients reacts to stored platelets differently from that of stable patients. In a similar vein, SlichteP proposed that sick patients may have an activated coagulation system that rapid11 removes activated, stored platelets.

At this stage, these are only speculations. However, as we continue to make progress in dealing with alloim- munization, it seems clear that we will still be left with a large population of patients who respond poorly to platelet transfusion. The depth and duration of throm- bocytopenia in many patients seem sure to increase as oncologists take advantage of the availability of hema- topoietic growth factors to increase the intensity of che- motherapeutic regimens. There is a clear need for understanding and innovation in this area.

Scorn MURPHY, MD Cardeza Foundation

for Hematology Research

1.

2.

3.

4.

5.

6.

7.

8.

9.

10.

11.

12.

13.

14.

15.

16.

17.

18.

19.

20.

21.

TRANSFUSION Vd. 32. No. 1-1992

Thomas Jefferson University 1015 Walnut Street

Philadelphia, PA 19107

References Murphy S. Preservation and clinical use of platelets. In: Williams WJ, Beutler E, Erslev AJ, Lichtman MA, eds. Hematology. 4th ed. New York McGraw-Hill, 1990:1654-9. Schiffer CA, Lee EJ, Ness PM, Reilly J. Clinical evaluation of platelet concentrates stored for one to five days. Blood 1986;67:1591-4. Bishop JF, McGrath K, Wolf MM. et al. Clinical factors influ- encing the efficacy of pooled platelet transfusions. Blood

Slichter SJ. Platelet transfusions a constantly evolving therapy. Thromb Hemost 1991;66:17&88. Nemo GJ, McCurdy PR. Prevention of platelet alloimmunization (editorial). Transfusion 1991;31:584-6. Bishop JF, Mathews JP, McGrath K. Yuen K, Wolf MM, Szer J. Factors Muencing 20-hour increments after platelet transfu- sion. Transfusion 1991;31:392-6. Hussein MA, Lee EJ, Schiffer CA. Platelet transfusions admin- istered to patients with splenomegaly. Transfusion 1990;30:50& 10. Blum SF, Shohet SB. Nathan DG, Gardner FH. The effed of am- photericin B on eryhxyte membrane cation permeability: its nla- tion b in vivo eryhxyte suxvival. J Lab Clin Med 1%9;73:98& 7. Wright DG. Robicbaud KJ. Pizzo PA, Deisseroth AB. Lethal pulmonary reactions associated with the combined use of ampho- tericin B and leukocyte transfusions. N Engl J Med 1981;304:1185- 90. Dana BW, Durie BGM, White RF, Huestis DW. Concomitant administration of granulocyte transfusions and amphotericin B in neutropenic patients: absence of signifcant pulmonary toxicity. Blood 1981;57:90-4. Forman SJ, ,Robinson GV, Wolf JL. Spruce WE, Blume KG. Pulmonary reactions associated with amphotericin B and leuko- cyte transfusions. N Engl J Med 1981;305:584-5. McGrath K, Bertram JF, Houghton S, et al. Amphotericin B- induced injury in stored human platelets. Transfusion 1992;32:46- 50. Holme S, Heaton WAL, Whitley P. Platelet storage lesions in second-generation containers: correlation with in vivo behavior with storage up to 14 days. Vox Sang 1990;59:12-8. Bode AP, Orton SM, Frye MJ, Udis BJ. Vesiculation of platelets during in vitro aging. Blood 1991;77:887-95. George JN, Picken EB. Heinz R. Platelet membrane glycoprotein changes during the preparation and storage of platelet concen- trates. Transfusion 1988;28:123-6. Fijnheer R. Modderman PW. Veldman H. et al. Detection of platelet activation with monoclonal antibodies and flow cytome- try: changes during platelet storage. Transfusion 1990;30:20-5. Bode AP. Platelet activation may explain the storage lesion in platelet concentrates. Blood Cells 1990,16:109-25; discussion 125-6. Murphy S. Kahn RA. Holme S, et al. Improved storage of plate- lets for transfusion in a new container. Blood 1982;60:194-200. Peter-Salonen K, Bucher U, Nydegger UE. Comparison of post- transfusion recoveries achieved with either fresh or stored platelet concentrates. Blut 1987;54:207-12. Rinder HM. Bonan JL, Rinder CS, Ault KA. Smith BR. Dynam- ics of leukocyte-platelet adhesion in whole blood. Blood 1991;78:1730-7. Slichter SJ. Mechanisms and management of platelet refractori- ness. In: Nance ST, ed. Transfusion medicine in the 1990's. Ar- lington: American Association of Blood Banks, 1990:95-179.

1988;71:383-7.