Chapter 26 Immunoglobulin Therapy Flashcards
What is the main purpose of immunoglobulin administration in equine practice?
To provide passive immunity, manage infectious diseases, and offer immunomodulation for conditions like immune-mediated thrombocytopenia.
What are the forms of immunoglobulin products used in equine therapy?
Plasma, serum, or concentrated immunoglobulin proteins.
What conditions indicate the use of immunoglobulin therapy in horses?
Failure of passive transfer, prophylaxis from infectious diseases, management of infectious gastrointestinal diseases, hypoproteinemia, endotoxin neutralization, and immune-mediated thrombocytopenia.
What document aids equine practitioners in selecting immunoglobulin products?
The AAEP Biologics and Therapeutic Agents Committee’s White Paper on Equine Plasma and Serum Products.
Why is the use of licensed products preferred over non-licensed ones in immunoglobulin therapy?
Licensed products ensure safety, efficacy, and regulatory compliance, whereas non-licensed products lack regulatory oversight.
What should practitioners do if they are uncertain about the licensing process for immunoglobulin products?
Contact the USDA Center for Veterinary Biologics or visit their website for information.
What are the main advantages of using fresh-frozen plasma in neonatal foals with failure of passive transfer?
Increases circulating IgG concentration, provides bactericidal and neutralizing activities, and improves cardiovascular stability.
What is the target IgG concentration in neonatal foals receiving plasma for failure of passive transfer?
Above 800 mg/dL, ideally above 1000 mg/dL.
What are the primary pathogens against which immunoglobulins provide protection in foals with failure of passive transfer?
Gram-negative bacteria.
What is the standard dose of fresh-frozen plasma for a foal with partial failure of passive transfer?
20 mL/kg, approximately 1 L of plasma per 50 kg foal.
What are the potential adverse reactions during plasma transfusion in foals?
Elevated respiratory rate or effort, tachycardia, pyrexia, and hypersensitivity reactions.
When should circulating IgG concentration be re-evaluated after plasma transfusion in foals?
Approximately 2–4 hours following the transfusion.
What conditions might necessitate repeat plasma transfusions in foals?
Ongoing sepsis and pathogen challenge.
What is the purpose of administering immunoglobulins to septic equine patients?
To neutralize circulating endotoxin and manage systemic inflammatory response.
What are the key components of endotoxin in Gram-negative bacteria?
Lipopolysaccharide (LPS).
What are the clinical signs of endotoxemia in horses?
Altered core body temperature, tachycardia, injected mucous membranes, prolonged capillary refill time, and intestinal hypomotility.
What severe complications can arise from endotoxemia in horses?
Disseminated intravascular coagulation, vascular thrombosis, and laminitis.
What types of plasma products are preferred for endotoxemic patients?
Products originating from horses hyperimmunized against Salmonella and E. coli.
What additional proteins in fresh-frozen plasma benefit septic equine patients?
Albumin, protein C, fibronectin, and antithrombin.
Why is fibronectin important in managing septic equine patients?
It aids in the clearance of immune complexes, damaged platelets, and particulate matter, stabilizes blood clot organization, and facilitates wound healing.
What is the significance of antithrombin in treating septic horses?
Provides anticoagulant and anti-inflammatory properties, and its restoration is crucial for managing coagulation disorders.
What is a potential risk of combining heparin with antithrombin in plasma transfusion?
Heparin may attenuate the anti-inflammatory effects of antithrombin.
What is the recommended treatment for hypoproteinemic equine patients?
Human albumin has been reported as a safe and efficacious colloidal therapy, though large-scale clinical trials are lacking.
What adverse reactions can occur with the use of human albumin in equine patients?
Facial swelling and delayed-type hypersensitivity reactions.
What is the primary aim of administering hyperimmune plasma against Rhodococcus equi in foals?
To prevent R. equi-associated pneumonia on endemic farms.
What are important considerations for administering hyperimmune plasma for Rhodococcus equi prophylaxis?
Administer at least 1 L of licensed hyperimmune plasma no later than the second day of life, with a possible additional liter at 14–32 days of age.
What is the role of intravenous immunoglobulin (IVIg) therapy in treating immune-mediated thrombocytopenia (IMT) in horses?
Dilutes and removes antibodies targeted against platelet surface proteins, providing therapeutic benefit.
What is the recommended dose of plasma for treating IMT in horses?
20 ml/kg/day for 2–5 days.
What are the multifaceted mechanisms of treatment success with high-dose plasma transfusion for IMT?
Blocked Fc receptor binding, steric hindrance of immune complex adherence, enhanced T-lymphocyte suppressor activity, and reduced B-lymphocyte function.
What is the main immunologic benefit of immunoglobulin therapy in horses with hypoproteinemia?
Provides essential proteins, increases oncotic pressure, and improves cardiovascular stability.
What are the potential risks associated with the administration of immunoglobulin therapy?
Immediate or delayed hypersensitivity reactions, hypocalcemia, intravascular volume overexpansion, and hepatic necrosis.
Why is close patient monitoring imperative during immunoglobulin therapy?
To detect and manage potential adverse hypersensitivity reactions.
What is the significance of using licensed immunoglobulin products?
Ensures the product is harvested from healthy donors free from infectious diseases, and adheres to regulatory standards for safety and efficacy.
What are the clinical signs of a hypersensitivity reaction to plasma transfusion?
Elevated respiratory rate or effort, tachycardia, pyrexia, and anaphylaxis.
What is the effect of ongoing sepsis on the half-life of circulating antibody proteins from plasma transfusion?
Results in enhanced catabolism and an abbreviated half-life of circulating antibody proteins.
What is the purpose of hyperimmunizing donor horses for plasma products?
To ensure high levels of specific antibodies against targeted pathogens, providing effective prophylaxis and treatment.
What is the role of antithrombin in managing coagulopathies in septic horses?
Restores depleted antithrombin levels, providing anticoagulant and anti-inflammatory effects.
What are the benefits of fresh-frozen plasma in managing endotoxemia?
Neutralizes endotoxins, provides essential proteins, and improves coagulation and inflammatory profiles.
What are the potential benefits of using immunoglobulin therapy in equine patients with severe gastrointestinal diseases?
Regulates altered coagulation profiles, balances inflammatory pathways, and improves overall patient stability.
What is the impact of fibronectin on the immune response in septic equine patients?
Facilitates the clearance of immune complexes and stabilizes blood clot organization, aiding in the resolution of systemic inflammation.
What is the recommended dose of fresh-frozen plasma for foals with complete failure of passive transfer?
Up to 2 L to achieve adequate IgG levels.
What are the clinical indications for using hyperimmune plasma against Streptococcus equi in horses?
Treatment of Streptococcus equi infections, including Strangles.
What is the role of endotoxin-neutralizing immunoglobulins in managing Gram-negative sepsis?
Reduces the expression and signaling of inflammatory mediators, improving clinical outcomes.
What is the therapeutic effect of immunoglobulin therapy in immune-mediated thrombocytopenia?
Dilution and removal of antibodies targeted against platelet surface proteins, enhancing platelet survival.
What is the potential adverse reaction of hepatic necrosis associated with plasma therapy called?
Theiler’s disease.
What are the clinical outcomes of using human albumin as a colloidal therapy in equine patients?
Safe and efficacious, though adverse events like hypersensitivity reactions may occur.
What is the importance of administering immunoglobulin therapy prior to pathogen challenge in foals?
Provides protection against infections, reducing morbidity and mortality during the perinatal period.
