Book Reviews

Abstract

Immunomodulatory Effects of Blood Transfusion. Edited by Eleftherios C. Vamvakas and Morris A. Blajchman. AABB Press, Bethesda, MD, USA, 1999. Pp. 295. ISBN: 1-56395-110-X. Currently, the most controversial and most widely discussed aspect of blood transfusion is the immunomodulatory effects of the transfusion of blood and blood components. Now that the effects of viral and other microbial agents are sufficiently mapped and understood, scientific and political attention focuses on the possible and thinkable effects of white blood cells in human blood components for transfusion. This book provides a comprehensive and critical review of the scientific state of the art, recognizing that such states of the art do change in a very dynamic manner. It is also recognized that there are disappointingly few hard scientific data, but an overwhelming variety of hypotheses and scientific assumptions that bear the risk of easy extrapolation in the ‘totum pro partum’ principle. The first two chapters deal with the history of the immunomodulation concept and the complexity of the human immune response. Chapters 3–5 provide animal experimental data on the effects of blood transfusion in relation to tumour growth, organ transplantation and risk of infection. Chapter 6 provides insight on proposed mechanisms of immunomodulatory effects of allogeneic blood transfusion, bringing the book to the paramount point of interpretation of findings of published clinical studies of the immunomodulatory effects of blood transfusion. This chapter is probably the most important part of the book, written by one of the exclusive experts in the field of meta-analysis, statistical evaluation and interpretation of rationale, objectives and findings of such studies. This chapter is followed by three chapters on the most relevant clinical effects so far discussed: survival of renal transplants, recurrence of cancer and infection. Chapter 11 discusses the possible effects of activation of dormant viruses, in particular CMV and HIV, besides valuable remarks on the immune effects of chronic exposure to clotting factor concentrates in patients with haemophilia. Chapter 12 adds some information on debatable clinical conditions related to blood transfusion, such as recurrent abortion and rheumatoid arthritis. The editors, reinforced by one of the expert panel members, conclude the book with an attempt to appraise the available evidence of deleterious effects of transfusion-associated immunomodulation and some recommendations for prevention. There is a balanced, although somewhat provocative, discussion on the pros and cons of the public policy-determined universal leucocyte depletion in the summary. All three authors share the belief that an adverse immunomodulatory effect of allogeneic blood transfusion probably exists, but also believe that such an effect is of modest magnitude. They argue that because of the small magnitude of the effect and the strong relationship between the need for transfusion and illness severity, it has been difficult to document the existence of this effect after adjusting appropriately for confounding factors. Therefore, the authors plead strongly for continuation of well-conducted, preferably double-blind, investigations of the purported deleterious immunomodulatory effects of allogeneic blood transfusions, beside the need for critical cost-benefit evaluation with respect to quality of life gained. The book is recommended as an important reference to determine the actual and future scientific ‘state of the art’ in immunomodulatory effects of allogeneic blood transfusion.