Risk of immunologic reactions to human serum albumin solutions

Abstract

MADAM We write to highlight the potential risk of immunologic reactions to human serum albumin (HSA) solutions. Recent advances in veterinary emergency and critical care and the greater availability of HSA solutions has led to increased use of these products in small animals. We feel that the potential for adverse reactions to HSA solutions is not widely recognised however. Recent research has identified a dichotomous response to the use of HSA solutions in critically ill versus healthy dogs. In critically ill dogs, HSA was reportedly associated with a low number of mild adverse effects although several serious adverse drug reactions were also potentially attributable to HSA administration (Mathews and Barry 2005, Trow and others 2008). In contrast, administration of HSA to healthy animals may be fatal (Francis and others 2007). A study by Martin and others (2008) suggested this may be due to different patterns of anti-HSA antibody production by these two populations. Importantly, of the 68 healthy dogs with no known prior HSA exposure sampled by Martin and others, 7 per cent had pre-existing anti-HSA antibodies. HSA is antigenic in both healthy and in critically ill dogs and repeat administration of HSA to previously exposed dogs can lead to severe anaphylactic reactions and should not be performed (Cohn and others 2007, Martin and others 2008). Based on these studies the potential risks of using HSA must be carefully considered before the product is administered. Published reports suggest that HSA solutions do increase serum albumin concentrations and colloid osmotic pressure although this may not be associated with a survival benefit. As such, we suggest that other colloids may offer safer alternatives for provision of oncotic support and HSA solutions should only be administered if other forms of treatment have failed. At present, no veterinary licensed preparations containing human serum albumin are available. Use of these products is therefore subject to the cascade as described by the Veterinary Medicines Regulations 2008 thus requiring veterinary surgeons to ensure clients are made aware of the risks of using such a product. At the Queen Mother Hospital for Animals, we record the use of HSA prominently within patients’ medical records. In addition, in our written communications to referring practitioners, we report the use of these solutions in order to prevent inadvertent repeat HSA administration. If the decision to administer HSA is made, we would strongly encourage readers to diligently and prominently record HSA use in the medical records of their patients. In addition, we also feel it is essential that this information be conveyed to any specialist referral centre to which the patient is transferred. Provision of this information may help prevent potentially fatal acute hypersensitivity reactions.