Type III Hypersensitivity Reactions in Critically Ill Dogs

Type III hypersensitivity reactions (HRs) are delayed immune responses to an antigenic substance. Immune complexes from this reaction can deposit in blood vessel walls, glomeruli, and synovia, causing a cascade of responses that can lead to vasculitis, glomerulonephritis, or arthritis. Type III HRs to human serum albumin (HSA) have been documented in healthy dogs. Clinical signs can include lethargy, edema, vasculitis, ecchymoses, lameness, fever, vomiting, hypovolemic shock, oliguria, and death. HSA is used in both humans and dogs to treat significant hypoalbuminemia. The authors described the first documented type III HR occurring in critically ill dogs given HSA.

The first patient was a 6-year-old spayed rottweiler with a septic abdomen caused by small intestinal perforation. The dog was taken to surgery, developed hypoalbuminemia, and was treated with HSA. Sixteen days later, the dog demonstrated signs of a type III HR. The second patient, a 10-year-old castrated Norwegian elkhound, was surgically treated to remove an intestinal foreign body and administered HSA; signs of a type III HR developed 8 days later. Skin biopsies from both dogs showed epidermal pallor, edema, hemorrhage, degenerative neutrophilic perivascular infiltrates, and multifocal areas of neutrophilic or leukocytoclastic vasculitis. Immunohistochemical staining also suggested HSA antigen-antibody complex deposition in the dermis. Treatment for the reactions included steroids and antihistamines; both dogs recovered from the HR with no further sequelae.

Commentary

HSA has previously been reported to cause delayed HRs in healthy dogs, and there is a common perception that critically ill dogs are not susceptible or less susceptible to HRs after HSA infusion. This article provided a summary of type III HRs and described 2 dogs that postoperatively received HSA for treatment of severe hypoalbuminemia. Both dogs developed peripheral edema, and skin biopsies showed convincing evidence of a type III hypersensitivity reaction. The take-home: critically ill dogs are also susceptible to the development of HRs.—Daniel S. Foy, MS, DVM, DACVIM, DACVECC

Source

Type III hypersensitivity reaction with immune complex deposition in 2 critically ill dogs administered human serum albumin. Powell C, Thompson L, Murtaugh RJ. JVECC 23:598-604, 2013.