Serum antibodies against human albumin in critically ill and healthy dogs

Albumins represent highly cross-reactive animal allergens

Albumins from animals are highly cross-reactive allergens for patients suffering from immunoglobulin E (IgE)-mediated allergy. Approximately 20-30% of cat and dog allergic patients show IgE reactivity and mount IgE-mediated allergic reactions to cat and dog albumin. It is astonishing that allergic patients can develop specific IgE responses against animal albumins because these proteins exhibit a more than 70% sequence identity to human serum albumin (HSA) which is the most abundant protein in the blood of the human body. The sequence identity of cat albumin (Fel d 2) and dog albumin (Can f 3) and HSA are 82% and 80%, respectively. Given the high degree of sequence identity between the latter two allergens and HSA one would expect that immunological tolerance would prohibit IgE sensitization to Fel d 2 and Can f 3. Here we discuss two possibilities for how IgE sensitization to Fel d 2 and Can f 3 may develop. One possibility is the failed development of immune tolerance in albumin-allergic patients whereas the other possibility is highly selective immune tolerance to HSA but not to Fel d 2 and Can f 3. If the first assumption is correct it should be possible to detect HSA-specific T cell responses and HSA-containing immune complexes in sensitized patients. In the latter scenario few differences in the sequences of Fel d 2 and Can f 3 as compared to HSA would be responsible for the development of selective T cell and B cell responses towards Fel d 2 as well as Can f 3. However, the immunological mechanisms of albumin sensitization have not yet been investigated in detail although this will be important for the development of allergen-specific prevention and allergen-specific immunotherapy (AIT) strategies for allergy to albumin.

Evaluation of bacterial growth, effects on albumin, and coagulation factors in canine fresh frozen plasma administered as continuous rate infusion exposed to room temperature for 12 hours

OBJECTIVES

To determine the risk of bacterial growth and to analyze the stability of albumin and coagulation factors in canine fresh frozen plasma (FFP) units exposed to room temperature (24°C) administered as a continuous rate infusion (CRI) for 12 hours.

DESIGN

Ex vivo study.

SETTING

University teaching hospital and pet blood bank.

ANIMALS

None.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

An FFP CRI was simulated to replicate the standard routine procedure used in dogs. Plasma samples were collected before starting the CRI (H0), after 4 hours (H4), and after 12 hours (H12). Bacterial culture of FFP was performed and albumin concentration and specific activity levels for factors V, VII, VIII, and IX were measured and compared. All plasma culture results were negative. There were no statistically significant differences at any time point in the factor VIII activity (median 105.5% [range, 75.6%-142.0%] at H0; median 107.8% [range, 75.0%-172.7%] at H4; and median 112.1% [range, 81.7%-171.0%] at H12); factor IX activity (median 119.3% [range, 89.1%-175.9%] at H0; median 123.1% [range, 72.5%-172.7%] at H4; and median 118.3% [range, 86.6%-177.5%] at H12); or albumin concentration (median 21.0 g/L [range, 17.0-23.0 g/L] at H0 and median 20.0 g/L [range, 17.0-24.0 g/L] at H12). A slight but significant increase in factor V activity was observed when comparing H0 (median 107.0% [range, 71.0%-159.0%]) to H4 (median 117.7% [range, 71.0%-176.7%]) (P = 0.002) or H12 (median 116.2% [range, 71.0%-191.6%]) (P = 0.001). A slight but significant increase in factor VII activity was observed when comparing H0 (median 115.4% [range, 70.6%-183.7%]) to H4 (median 118.2% [range, 82.7%-194.6%]) (P = 0.005); H0 to H12 (median 128.7% [range, 86.4%-200.0%]) (P < 0.001); and H4 to H12 (P = 0.002).

CONCLUSIONS

FFP CRI at room temperature for 12 hours could be considered safe with regard to risk for bacterial growth and also effective by providing albumin and clotting factors.

Successful Use of Mycophenolate Mofetil as Adjunct to Prednisolone for Treatment of Acute Kidney Injury Secondary to Human Serum Albumin Administration in a Dog

The use of human serum albumin (HSA) is described in dogs receiving critical care. However, despite the high degree of homology, anaphylactic and delayed hypersensitivity reactions are reported. Delayed type III hypersensitivity reactions can lead to glomerulonephritis and acute kidney injury (AKI). Undiluted 20% HSA was administered to a 4.8 yr old intact male Labrador Retriever with severe hypoalbuminemia, following surgical management of septic peritonitis of gastrointestinal origin. Nineteen days after HSA administration, the dog developed peracute high magnitude renal proteinuria and AKI. Rapid immunosuppression, using a combination of prednisolone and mycophenolate mofetil, resulted in full resolution of AKI, hypoalbuminemia, and proteinuria. Addition of mycophenolate mofetil may have resulted in the first documented case of full renal recovery from hypersensitivity-induced AKI caused by HSA administration.

Therapeutic plasma exchange for the management of a type III hypersensitivity reaction and suspected immune-mediated vasculitis assumed to be caused by human albumin administration in a dog

OBJECTIVE

To describe the successful treatment of a life-threatening type III hypersensitivity reaction suspected to have been related to human serum albumin (HSA) administration in a dog with therapeutic plasma exchange (TPE).

CASE SUMMARY

A 3-year-old neutered male mixed breed dog was suspected to have developed immune-mediated vasculitis 2 weeks after the administration of HSA (740 mg/kg) for the management of hypoalbuminemia resulting from septic peritonitis. The dog was presented with fever, edema, hypoalbuminemia (26 g/L [2.6 g/dL]; reference interval, 30-44 g/L [3.0-4.4 g/dL]), and coagulopathy. The dog was treated with fresh frozen plasma (FFP) and glucocorticoids but remained hypoalbuminemic (18 g/L [1.8 g/dL]) and developed acute kidney injury (AKI). Over 4 days, 3 TPE treatments were performed, with a total of 2.7 plasma volumes exchanged. Replacement fluids consisted of a combination of FFP, hydroxyethyl starch 6%, and 0.9% saline solution. Following TPE treatments, serum albumin concentration increased (from 18 g/L [1.8 g/dL] to 25 g/L [2.5 g/dL]), serum creatinine concentration decreased (from 340 μmol/L [3.9 mg/dL] to 87 μmol/L [0.98 mg/dL]), and clotting times normalized (activated partial thromboplastin time decreased from 33 seconds to 14.5 seconds). There was a gradual but consistent clinical improvement of the edema and overall demeanor of the dog. No significant adverse effects were noted during the TPE treatments, and the dog was discharged after 8 days of hospitalization. Following discharge, the dog had complete clinical resolution of edema and AKI. NEW/UNIQUE INFORMATION: This is the first report describing successful use of TPE for the management of an immune-mediated reaction (type III hypersensitivity) following HSA administration.

Colloids Yes or No? - a "Gretchen Question" Answered

Colloid solutions, both natural and synthetic, had been widely accepted as having superior volume expanding effects than crystalloids. Synthetic colloid solutions were previously considered at least as effective as natural colloids, as well as being cheaper and easily available. As a result, synthetic colloids (and HES in particular) were the preferred resuscitation fluid in many countries. In the past decade, several cascading events have called into question their efficacy and revealed their harmful effects. In 2013, the medicines authorities placed substantial restrictions on HES administration in people which has resulted in an overall decrease in their use. Whether natural colloids (such as albumin-containing solutions) should replace synthetic colloids remains inconclusive based on the current evidence. Albumin seems to be safer than synthetic colloids in people, but clear evidence of a positive effect on survival is still lacking. Furthermore, species-specific albumin is not widely available, while xenotransfusions with human serum albumin have known side effects. Veterinary data on the safety and efficacy of synthetic and natural colloids is limited to mostly retrospective evaluations or experimental studies with small numbers of patients (mainly dogs). Large, prospective, randomized, long-term outcome-oriented studies are lacking. This review focuses on advantages and disadvantages of synthetic and natural colloids in veterinary medicine. Adopting human guidelines is weighed against the particularities of our specific patient populations, including the risk-benefit ratio and lack of alternatives available in human medicine.

A survey of emergency and critical care veterinarians regarding IV fluid bolus therapy and monitoring practices in small animals

OBJECTIVE

To determine how veterinary emergency and critical care clinicians define IV fluid bolus therapy (FBT) and what constitutes a positive response to a fluid bolus.

DESIGN

Online survey of 222 emergency and critical care veterinarians between December 17, 2018, and March 1, 2019.

INTERVENTIONS

An online survey was provided to diplomates of the American College of Veterinary Emergency and Critical Care (ACVECC), residents of ACVECC-approved training programs, as well as house officers and emergency clinicians of a corporate multicenter emergency and specialty care veterinary hospital. The survey investigated the administration of various crystalloid, colloid, and blood products for FBT, as well as expected physiological responses.

MEASUREMENTS AND MAIN RESULTS

The majority of respondents considered balanced isotonic crystalloids appropriate for FBT (220/222 [99.1%]). Respondents showed greater variability in acceptance of 0.9% sodium chloride (105/222 [47.30%]), hypertonic (3-7%) sodium chloride (131/222 [59.01%]), and hydroxyethyl starch solutions (90/222 [40.54%]). Most respondents did not consider physiological plasma (44/222 [19.82%]) an appropriate choice. The most commonly used parameters for monitoring FBT responses were heart rate (220/222 [99.10%]), blood pressure (217/222 [97.75%]), capillary refill time (192/222 [86.49%]), lactate (181/222 [81.53%]), pulse pressure (151/222 [68.02%]), and rectal temperature (145/222 [65.32%]). The majority of respondents perceived that 0-20% (165/222 [74.32%]) of hypotensive patients are nonresponsive to FBT.

CONCLUSIONS

Small animal emergency and critical care clinicians favored balanced isotonic electrolyte solutions and hypertonic sodium chloride solutions for FBT over other options. When monitoring responses to FBT, heart rate, blood pressure, capillary refill time, and plasma lactate were among the most commonly monitored parameters, and there was a lack of familiarity with others. Despite the widespread use of FBT, these findings outline the need for further prospective clinical trials regarding the ideal fluid type and rate, as well as the appropriate responses to FBT.

Update on Canine Parvoviral Enteritis

Canine parvoviral enteritis is one of the most common causes of morbidity and mortality in dogs worldwide. Tests can detect viral antigen in feces, and characteristic decreases in total leukocyte, neutrophil, and lymphocyte counts can increase the index of suspicion in affected cases and can be used to prognosticate morbidity and mortality. The standard of care for infected animals includes IV crystalloid and sometimes colloid fluids, antiemetics, broad-spectrum antibiotics, and early enteral nutrition. Vaccination induces protective immunity in most dogs. Vaccination, along with limiting exposure in young puppies, is the most effective means of preventing parvoviral enteritis in dogs.

Update on Albumin Therapy in Critical Illness

Albumin is among the most important proteins and plays a significant role in maintenance of colloid osmotic pressure, wound healing, decreasing oxidative damage, carrying drugs and endogenous substances, and coagulation. Hypoalbuminemia is common in acute and chronic illnesses. Replenishment of albumin can be in the form of fresh frozen, frozen or cryopoor plasma, or in the form of human or canine albumin concentrates. Infusion of human albumin concentrate to healthy and critically ill dogs can induce acute and delayed hypersensitivity reactions. Death has been reported. Therefore, allogenic transfusion in the form of plasma products or canine albumin concentrate is recommended.

Delayed type III hypersensitivity reaction with acute kidney injury in two dogs following administration of concentrated human albumin during treatment for hypoalbuminemia secondary to septic peritonitis

OBJECTIVE

To describe 2 dogs with acute kidney injury secondary to type III hypersensitivity reaction to 25% human serum albumin (HSA).

CASE SERIES SUMMARY

Two dogs were presented with evidence of septic peritonitis. The dogs were hospitalized following definitive surgical correction of a jejunal laceration following routine ovariohysterectomy, and removal of a jejunal foreign body. In the postoperative period, both dogs developed hypoalbuminemia and received 25% HSA. At the time of initial discharge, both dogs were doing well clinically and had normal renal parameters. Eleven and 18 days after HSA infusion, respectively, both dogs were re-presented with clinical signs of inappetence, vomiting, and lameness that progressed to urticaria, peripheral and angioedema, and petechiae, consistent with a delayed type III hypersensitivity reaction. Treatment for the type III hypersensitivity reaction to HSA included administration of diphenhydramine and glucocorticoids. Despite partial resolution of edema and joint swelling, both dogs developed progressive azotemia together with hypoalbuminemia and proteinuria. One dog developed an anuric acute kidney injury (AKI). Both dogs were humanely euthanized. Histopathology of the kidneys of both dogs was consistent with immune complex deposition and vasculitis.

NEW OR UNIQUE INFORMATION

Severe type III hypersensitivity reactions have been documented in healthy dogs and clinical patients following the administration of HSA. This report describes the first documented delayed type III hypersensitivity reaction in 2 dogs with septic peritonitis that resulted in AKI, glomerulonephritis, and oligo- to anuria in clinical patients following administration of 25% HSA.

Purification of canine albumin by heat denaturation in a plasma bag

OBJECTIVE

To design and evaluate a method to purify canine albumin from fresh frozen plasma (FFP) or stored plasma (SP) in a manner that could be applied clinically.

DESIGN

In vitro experimental study.

SETTING

FDA licensed Blood Bank Laboratory and University biochemistry laboratory.

ANIMALS

None.

INTERVENTIONS

Using equipment that is typically found in veterinary blood banks, plasma bags were thawed, injected with the heat stabilizing agent, sodium caprylate, and then heated and acidified to denature all but albumin proteins. Albumin-rich supernatant was removed, the pH was neutralized, and then pasteurized and refrigerated. Albumin and total plasma protein concentrations were measured and the product was cultured for bacteria at 0, 7, 14, 30, and 60 days post-processing.

MEASUREMENTS AND MAIN RESULTS

Seventeen bags of plasma were analyzed for purity, yield, and sterility of the finished albumin product. Bags were divided into categories based on the age of the frozen plasma. Mean yield of albumin for all bags was 77.3% and mean purity was 91.2%. There was no difference between old stored plasma, new stored plasma, and FFP with regard to yield (P = 0.31) or purity (P = 0.24) based on one-way analysis of variances. Overall 1 of 17 bags of plasma (5.9%) tested positive for bacterial contamination on day 60 after processing.

CONCLUSIONS

Sodium caprylate is able to stabilize canine albumin enabling it to withstand heating that denatures other plasma proteins. The resulting albumin product is of sufficient quality to potentially be used therapeutically as a colloidal resuscitative fluid. Further study is needed into its safety and effect in dogs.

The endothelial glycocalyx: Structure and function in health and critical illness

OBJECTIVE

To conduct a narrative review of the current literature in reference to the structure and function of the endothelial glycocalyx (EG) and its contribution to the pathophysiology of conditions relevant to the veterinary emergency and critical care clinician. Novel therapies for restoring or preserving the EG will also be discussed.

DATA SOURCES

Online databases (PubMed, CAB abstracts, Scopus) were searched between January 1st 2017 and May 1st 2017 for English language articles without publication date restriction. Keywords included EG, endothelial surface layer, degradation, syndecan-1, heparan sulfate, critical illness, sepsis, trauma, and therapeutics.

DATA SYNTHESIS

The EG is a complex and important structure located on the luminal surface of all blood vessels throughout the body. It plays an important role in normal vascular homeostasis including control of fluid exchange across the vascular barrier. Loss or degradation of the EG has an impact on inflammation, coagulation, and vascular permeability and tone. These changes are essential components in the pathophysiology of many conditions including sepsis and trauma. A substantial body of experimental animal and human clinical research over the last decade has demonstrated increased circulating concentrations of EG degradation products in these conditions. However, veterinary-specific research into the EG and critical illness is currently lacking. The utility of EG degradation products as diagnostic and prognostic tools continues to be investigated and new therapies to preserve or improve EG structure and function are under development.

CONCLUSIONS

The recognition of the presence of the EG has changed our understanding of transvascular fluid flux and the pathophysiology of many conditions of critical illness. The EG is an exciting target for novel therapeutics to improve morbidity and mortality in conditions such as sepsis and trauma.

Clinical use of cryopoor plasma continuous rate infusion in critically ill, hypoalbuminemic dogs

OBJECTIVE

To investigate the impact of cryopoor plasma (CPP) continuous rate infusion (CRI) on albumin concentration and colloid osmotic pressure (COP) in critically ill dogs with hypoalbuminemia.

DESIGN

Retrospective study between 2013 and 2015 with a 90-day follow-up on survivors.

SETTING

University teaching hospital.

ANIMALS

Ten hypoalbuminemic dogs receiving a CPP CRI for albumin replacement or oncotic support. All patients with documented hypoalbuminemia or low COP receiving CPP administration for albumin or oncotic support during the study period were included.

INTERVENTIONS

CRI of CPP.

MEASUREMENTS AND MAIN RESULTS

Mean age was 7.4 ± 4.5 years. Mean survival prediction index score was 0.66 ± 0.13. Seven dogs were septic, with 2 of 7 in septic shock and 5 of 7 having septic peritonitis. The mean pre- and postinfusion albumin was 15 ± 4 g/L and 21 ± 2 g/L, respectively. The median pre- and postinfusion COP was 8.6 mm Hg (4.9-9.7 mm Hg) and 10.2 mm Hg (8.1-13.3 mm Hg), respectively. The median duration of CRI was 16 hours (11-121 h). The mean CPP rate was 1.8 ± 0.6 mL/kg/h, the mean crystalloid rate administered concurrently was 0.8 ± 0.9 mL/kg/h, and the mean hydroxyethyl starch rate administered concurrently was 1.2 ± 0.9 mL/kg/h. The difference in pre- and postinfusion albumin was significantly correlated with CPP rate (P = 0.0004), whereas the difference in pre- and postinfusion COP was correlated with hydroxyethyl starch rate (P = 0.0128). Mean duration of hospitalization was 8.6 ± 3.9 days. Mann-Whitney U and Fisher's exact tests were used to compare survivors and nonsurvivors. Survivors were significantly younger than nonsurvivors (3.5 vs 11.5 y, P = 0.033). No side effects were reported. Survival to discharge was 40% with identical 90-day survival. Of the nonsurvivors, 50% died naturally.

CONCLUSIONS

There was an association between the rate of CPP and the change in albumin after CPP CRI in critically ill dogs, suggesting that CPP may be a viable option for treatment of hypoalbuminemia.

Prospective Review of Clinical Hypersensitivity Reactions After Administration of 5% Human Serum Albumin in 40 Critically Ill Cats

This prospective study assesses the presence of immediate and delayed clinical hypersensitivity reactions in 40 hypoalbuminemic critically ill cats during and after an intravenous administration of 5% human serum albumin (HSA). Twenty hypoalbuminemic critically ill cats with no known exposure to HSA (control group) were also checked in order to highlight any clinical signs related to the underlying disease which could mimic hypersensitivity reactions. The administration of 10-20 mL/kg of 5% HSA at 2 mL/kg/h in critically ill cats did not lead to clinical signs of types I and III hypersensitivity reactions at days 0, 7, 14, 21, and 28, unlike previous findings with 25% HSA in this species.

Use of cryopoor plasma for albumin replacement and continuous antimicrobial infusion for treatment of septic peritonitis in a dog

OBJECTIVE

To report the successful management of a dog with septic peritonitis and septic shock secondary to enterectomy dehiscence using novel techniques for identification of intestinal dehiscence and for septic shock treatment.

CASE SUMMARY

A 5-year-old castrated male Bernese Mountain Dog presented for lethargy 6 days following enterotomy for foreign body obstruction. Septic peritonitis was identified due to dehiscence of the enterotomy site, and resection and anastomosis were performed using a gastrointestinal anastomosis and thoracoabdominal stapling device. Postoperatively the patient experienced severe hypotension, which responded to norepinephrine constant rate infusion (CRI) after failing to improve with fluid therapy or dopamine CRI. Further treatment included antimicrobial CRI and supportive care including careful fluid therapy. Due to low effective circulating volume paired with intersititial fluid overload and large volume abdominal effusion, fluid therapy consisted of a combination of human serum albumin, canine albumin, synthetic colloids, and isotonic crystalloids. Cryopoor plasma (CPP) was used as a source of canine albumin and intravascular volume. On Day 4, food dye was given through a nasogastric tube due to suspicion of dehiscence of the anastomosis site. Dehiscence was confirmed during abdominal exploratory, and a second resection and anastomosis was performed. Abdominal partial closure with vacuum-assisted closure device was performed. Supportive care was continued with CPP CRI and imipenem CRI. Planned relaparotomy to change the vacuum-assisted closure device was performed 48 hours later, with abdominal closure 96 hours after anastomosis. The patient was discharged on Day 15. Recheck 12 months later was normal.

NEW OR UNIQUE INFORMATION PROVIDED

This case includes novel techniques such food dye via nasogastric tube to identify anastomosis dehiscence, use of CPP as a source of canine albumin, and antimicrobial CRI in a dog with septic peritonitis.

The Colloid Controversy: Are Colloids Bad and What Are the Options?

Biologic and synthetic colloid solutions are frequently used to increase oncotic pressure and to treat shock. Research has shown that each product has both risks and benefits. Hydroxyethyl starches have gained a reputation for increasing risk of death, acute kidney injury, and coagulation abnormalities in people, but additional studies are needed to see whether these concerns hold true in veterinary patients. This article reviews the risks and benefits of currently available products.

Natural and Synthetic Colloids in Veterinary Medicine

This review article covers basic physiology underlying the clinical use of natural and artificial colloids as well as provide practice recommendations. It also touches on the recent scrutiny of these products in human medicine and how this may have an effect on their use in veterinary medicine.

Retrospective evaluation of the administration of 25% human albumin to dogs with protein-losing enteropathy: 21 cases (2003-2013)

OBJECTIVE

To describe the administration of 25% human serum albumin (HSA) to dogs diagnosed with idiopathic inflammatory bowel disease (IBD) and protein-losing enteropathy (PLE). The secondary objectives were to report any acute and delayed adverse events and the effect of corticosteroids on the development of these reactions.

DESIGN

Retrospective study (2003-2013).

SETTING

Private referral hospital.

ANIMALS

Twenty-one client owned dogs diagnosed with PLE and idiopathic IBD that received ≥ 1 transfusion of 25% HSA. Dogs were included in the study if they had panhypoproteinemia, serum albumin concentration < 15.0 g/L [< 1.5 g/dL] or extravascular fluid accumulation, idiopathic IBD confirmed on histopathology, and complete medical records.

INTERVENTIONS

None.

MAIN RESULTS

Two of the 21 patients (9.5%) developed signs consistent with an acute reaction; 1 of these dogs was euthanized due to the severity of the reaction. Two patients (9.5%) showed signs consistent with a delayed reaction; 1 of these dogs was euthanized 5 days after the reaction, though it is unclear whether the reaction and the euthanasia were related. Corticosteroid administration did not appear to affect the occurrence of adverse reactions.

CONCLUSIONS

This retrospective study demonstrated that the administration of 25% HSA to dogs with moderate to severe hypoalbuminemia from PLE was associated with occasional acute and delayed adverse events, some of which were severe or fatal.

Controversies in the use of hydroxyethyl starch solutions in small animal emergency and critical care

OBJECTIVES

To (1) review the development and medical applications of hydroxyethyl starch (HES) solutions with particular emphasis on its physiochemical properties; (2) critically appraise the available evidence in human and veterinary medicine, and (3) evaluate the potential risks and benefits associated with their use in critically ill small animals.

DATA SOURCES

Human and veterinary original research articles, scientific reviews, and textbook sources from 1950 to the present.

HUMAN DATA SYNTHESIS

HES solutions have been used extensively in people for over 30 years and ever since its introduction there has been a great deal of debate over its safety and efficacy. Recently, results of seminal trials and meta-analyses showing increased risks related to kidney dysfunction and mortality in septic and critically ill patients, have led to the restriction of HES use in these patient populations by European regulatory authorities. Although the initial ban on the use of HES in Europe has been eased, proof regarding the benefits and safety profile of HES in trauma and surgical patient populations has been requested by these same European regulatory authorities.

VETERINARY DATA SYNTHESIS

The veterinary literature is limited mostly to experimental studies and clinical investigations with small populations of patients with short-term end points and there is insufficient evidence to generate recommendations.

CONCLUSIONS

Currently, there are no consensus recommendations regarding the use of HES in veterinary medicine. Veterinarians and institutions affected by the HES restrictions have had to critically reassess the risks and benefits related to HES usage based on the available information and sometimes adapt their procedures and policies based on their reassessment. Meanwhile, large, prospective, randomized veterinary studies evaluating HES use are needed to achieve relevant levels of evidence to enable formulation of specific veterinary guidelines.

Postoperative management of dogs with gastric dilatation and volvulus

The objective of the study was to review the veterinary literature for evidence-based and common clinical practice supporting the postoperative management of dogs with gastric dilatation and volvulus (GDV). GDV involves rapid accumulation of gas in the stomach, gastric volvulus, increased intragastric pressure, and decreased venous return. GDV is characterized by relative hypovolemic-distributive and cardiogenic shock, during which the whole body may be subjected to inadequate tissue perfusion and ischemia. Intensive postoperative management of the patients with GDV is essential for survival. Therapy in the postoperative period is focused on maintaining tissue perfusion along with intensive monitoring for prevention and early identification of ischemia-reperfusion injury (IRI) and consequent potential complications such as hypotension, cardiac arrhythmias, acute kidney injury (AKI), gastric ulceration, electrolyte imbalances, and pain. In addition, early identification of patients in need for re-exploration owing to gastric necrosis, abdominal sepsis, or splenic thrombosis is crucial. Therapy with intravenous lidocaine may play a central role in combating IRI and cardiac arrhythmias. The most serious complications of GDV are associated with IRI and consequent systemic inflammatory response syndrome and multiple organ dysfunction syndrome. Other reported complications include hypotension, AKI, disseminated intravascular coagulation, gastric ulceration, and cardiac arrhythmias. Despite appropriate medical and surgical treatment, the reported mortality rate in dogs with GDV is high (10%-28%). Dogs with GDV that are affected with gastric necrosis or develop AKI have higher mortality rates.

Transfusion medicine in small animals

This article reviews the use of transfusion medicine in veterinary medicine and discusses current research regarding donor screening and component therapy. Typing and crossmatching methodologies are discussed. Available components, potential uses, and controversies in treatment are also discussed.

Type III hypersensitivity reaction with immune complex deposition in 2 critically ill dogs administered human serum albumin

OBJECTIVE

To describe 2 cases of vasculitis that were attributed to a type III hypersensitivity reaction in critically ill dogs occurring 8-16 days postadministration of human serum albumin (HSA).

CASE OR SERIES SUMMARY

Skin biopsies were obtained from 3 different sites in 2 critically ill dogs that developed vasculitis 8-16 days following treatment with HSA. Histopathological findings from both dogs indicated epidermal pallor, widespread edema and hemorrhage, degenerative neutrophilic perivascular infiltrates, and multifocal areas of neutrophilic or leukocytoclastic vasculitis. Immunohistochemical staining using an anti-human serum albumin rabbit antibody suggested that the antigen-antibody complexes seen in the dermis were associated with the administration of HSA.

NEW OR UNIQUE INFORMATION PROVIDED

In this case series, we documented a leukocytoclastic vasculitis and probable antigen-antibody complexes to human albumin in the dermis of 2 critically ill dogs after administration of HSA. Previously, type III hypersensitivity reactions had only been reported in healthy dogs that had received HSA. This report also describes the potential use of immunohistochemical staining to detect the HSA antigen in tissue sections through the use of specifically labeled antibodies.

Serum albumins-unusual allergens

BACKGROUND

Albumins are multifunctional proteins present in the blood serum of animals. They can bind and transport a wide variety of ligands which they accommodate due to their conformational flexibility. Serum albumins are highly conserved both in amino acid sequence and three-dimensional structure. Several mammalian and avian serum albumins (SAs) are also allergens. Sensitization to one of the SAs coupled with the high degree of conservation between SAs may result in cross-reactive antibodies in allergic individuals. Sensitivity to SA generally begins with exposure to an aeroallergen, which can then lead to cross-sensitization to serum albumins present in food.

SCOPE OF REVIEW

This review focuses on the allergenicity of SAs presented in a structural context.

MAJOR CONCLUSIONS

SA allergenicity is unusual taking into account the high sequence identity and similarity between SA from different species and human serum albumin. Cross-reactivity of human antibodies towards different SAs is one of the most important characteristics of these allergens.

GENERAL SIGNIFICANCE

Establishing a relationship between sequence and structure of different SAs and their interactions with antibodies is crucial for understanding the mechanisms of cross-sensitization of atopic individuals. Structural information can also lead to better design and production of recombinant SAs to replace natural proteins in allergy testing and desensitization. Therefore, structural analyses are important for diagnostic and treatment purposes. This article is part of a Special Issue entitled Serum Albumin.

Use of therapeutic plasmapheresis in a case of canine immune-mediated hemolytic anemia

OBJECTIVE

To investigate the clinical application and potential utility of plasmapheresis in canine immune-mediated hemolytic anemia.

CASE SUMMARY

A 7-year-old spayed female Maltese diagnosed with immune-mediated hemolytic anemia was initially treated with prednisone, cyclosporine, and received multiple transfusions of packed RBC. Because of the progression of clinical signs despite traditional medical therapy, plasmapheresis was initiated. Plasma immunoglobulin G and immunoglobulin M levels were measured before, during, and after treatment to help determine if there had been a significant decrease in immunoglobulin levels with plasmapheresis. Plasmapheresis was successfully performed over a 2.5-hour period in this dog with minimal complications. Hypocalcemia was identified as a known complication of circuit anticoagulation, and was corrected through calcium supplementation. Post-plasmapheresis there was a decrease in immunoglobulin G and immunoglobulin M levels, and the patient showed clinical improvement. Following discharge the dog had no known complications of therapy, and had complete resolution of the anemia.

NEW OR UNIQUE INFORMATION PROVIDED

Plasmapheresis was performed successfully with minimal complications. Because transfusion requirements appeared to be reduced, and the procedure was well tolerated, there may be a place for this modality in severe cases to act as a bridge until medical therapy takes full effect. Because of the cost of performing this therapy, and the potential requirement for multiple treatments, it should be reserved for selected patients.