Clinical transfusion medicine

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.

Resuscitation Patterns and Massive Transfusion for the Critical Bleeding Dog-A Multicentric Retrospective Study of 69 Cases (2007-2013)

Objective: To describe resuscitation patterns of critically bleeding dogs, including those receiving massive transfusion (MT). Design: Retrospective study from three universities (2007-2013). Animals: Critically bleeding dogs, defined as dogs who received ≥ 25 ml/kg of blood products for treatment of hemorrhagic shock caused by blood loss. Measurements and Main Results: Sixty-nine dogs were included. Sources of critical bleeding were trauma (26.1%), intra/perioperative surgical period (26.1%), miscellaneous (24.6%), and spontaneous hemoabdomen (23.1%). Median (range) age was 7 years (0.5-18). Median body weight was 20 kg (2.6-57). Median pre-transfusion hematocrit, total protein, systolic blood pressure, and lactate were 25% (10-63), 4.1 g/dl (2-7.1), 80 mm Hg (20-181), and 6.4 mmol/L (1.1-18.2), respectively. Median blood product volume administered was 44 ml/kg (25-137.4). Median plasma to red blood cell ratio was 0.8 (0-4), and median non-blood product resuscitation fluid to blood product ratio was 0.5 (0-3.6). MT was given to 47.8% of dogs. Survival rate was 40.6%. The estimated odds of survival were higher by a factor of 1.8 (95% CI: 1.174, 3.094) for a dog with 1 g/dl higher total protein above reference interval and were lower by a factor of 0.6 (95% CI: 0.340, 0.915) per 100% prolongation of partial thromboplastin time above the reference interval. No predictors of MT were identified. Conclusions: Critical bleeding in dogs was associated with a wide range of resuscitation patterns and carries a guarded to poor prognosis.

Indications for use and complications associated with canine plasma products in 170 patients

OBJECTIVES

To describe a population of dogs receiving canine plasma products (PP), report the incidence of transfusion reactions (TR), and to identify whether this is higher when non-type-matched plasma is administered.

DESIGN

Retrospective study conducted on dogs receiving canine PP between March 2016 and January 2018.

SETTING

Private referral hospital with first opinion emergency clinic.

ANIMALS

One hundred and ninety-four privately owned dogs identified from the clinic electronic medical record system that received at least 1 unit of canine PP during the study period; 25 patients were excluded due to incomplete records.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

A search of computerized records was performed, identifying any patients that received canine PP between 2016 and 2018; clinical notes were examined to identify the number and type of TR associated. One hundred and sixty-nine cases were included in the study, receiving a total of 412 PP transfusions. Reactions were noted in 4% (17/412) of transfusions administered, with the vast majority being mild in nature. Of the TR identified, a greater proportion were in type-matched PP transfusions than non-type-matched, although this difference was not statistically significant (P = 0.7989). The number of dogs suffering a TR was higher (13%) when multiple units of plasma were administered than if only 1 unit was transfused (5%), but this was not statistically significant (P = 0.1161). Transfusion reactions were more likely to occur when packed red blood cells were also administered, although this was also not statistically significant (P = 0.07).

CONCLUSION

Administration of canine plasma products appears to be a safe procedure that carries a low risk of transfusion reactions. Type-matching of canine PP appears unnecessary and does not reduce incidence of TR in dogs.

Management of hemodynamic changes associated with removal of a large abdominal myofibroblastic tumor in a pony

A 22-year-old female Welsh-cross pony was evaluated because of intermittent colic, signs of depression, pyrexia, anorexia, muscle wasting with abdominal distention, and weight gain over the preceding 12 months. A large abdominal mass was detected and surgically removed; the hemodynamic alterations and complications caused by the dramatic fluid losses and shifts that can occur in association with removal of a large abdominal mass required extensive postoperative management. Monitoring of clinical and hematologic variables such as attitude, heart rate, mucous membrane color, mean arterial blood pressure, PCV, and plasma total protein concentration provided useful information for successful management of the patient after surgery. On removal, the tumor weighed 19% of the pony's body weight and was characterized as a myofibroblastic tumor. Myofibroblastic tumors should be considered as a differential for large internal abdominal masses in horses, and surgical removal may be feasible and life extending with appropriate postoperative care.

Efficacy of fresh-frozen plasma and cryoprecipitate in dogs with von Willebrand's disease or hemophilia A

Here we report the comparative efficacy of fresh-frozen plasma (FFP) and cryoprecipitate in the treatment of 2 inherited bleeding disorders in dogs. The dogs were divided into 3 groups, consisting of 4 Doberman Pinschers with type I von Willebrand's disease (vWD) (group 1), 1 Scottish Terrier with type III vWD (group 2), and 4 German Shepherd Dogs with hemophilia A (group 3). In vWD, therapeutic efficacy was determined by the ability of the products to increase von Willebrand factor antigen (vWf:Ag) concentrations above 35 canine units (CU)/dL and to correct the prolonged buccal mucosal bleeding time. Therapeutic efficacy in hemophilia A was assessed by the ability of the products to increase the factor VIII coagulant (FVIII:C) activity above 30 CU/dL. In both groups 1 and 2, higher increases in vWf:Ag were achieved with cryoprecipitate than with FFP, despite a significantly smaller total amount of vWf:Ag (in CU) being infused with cryoprecipitate. The maximum vWf:Ag attained after infusion in group 1 was dependent on both the baseline vWf:Ag concentration and on the type of infusion product. The dogs with vWD in both groups also displayed a delayed increase in FVIII:C activity after infusion of both plasma products, which is characteristic of the disease. In group 3, cryoprecipitate achieved similar increases in FVIII:C activity compared to FFP, although a significantly lesser amount of FVIII:C (in CU) was delivered with cryoprecipitate. Six of the 9 dogs treated with FFP experienced adverse effects ranging from mild pruritus to pallor and weakness, whereas none of the 9 dogs treated with cryoprecipitate had any observable adverse reactions (P = .009). Based on its efficacy and safety, we recommend cryoprecipitate over FFP for treatment or prophylaxis of hemorrhagic episodes in dogs with vWD or hemophilia A.

Pharmacokinetics of von Willebrand factor and factor VIII in canine von Willebrand disease and haemophilia A

The pharmacokinetics of von Willebrand factor antigen (vWf:Ag) and factor VIII coagulant (FVIII:C) activity in dogs with von Willebrand Disease (vWD) and haemophilia A, respectively, were assessed after the administration of fresh frozen plasma (FFP) and cryoprecipitate. Loading doses necessary to attain target plasma concentrations of each factor were estimated to be 63 U kg-1 BW for FFP and 13 U kg-1 BW for cryoprecipitate to reach 35 U dl-1 vWf:Ag in vWD and 23 U kg-1 BW for FFP and 4 U kg-1 BW for cryoprecipitate to reach 30 U dl-1 FVIII:C in haemophilia A. The estimated volumes of FFP required to attain these target concentrations (49 ml kg-1 BW for vWD and 20 ml kg-1 BW for haemophilia A) are approximately 10-fold higher than the volumes of cryoprecipitate required (4 ml kg-1 BW for vWD and 2 ml kg-1 BW for haemophilia A). This indicates that cryoprecipitate is a more efficient and practical means of treating or preventing haemorrhage in these two haemostatic disorders.

Stability of canine factor VIII and von Willebrand factor antigen concentration in the frozen state

The stability of factor VIII and von Willebrand factor antigen concentration in the frozen state was assessed. Citrated plasma was obtained from 10 healthy, mixed breed dogs and separated into 300 microliters aliquots. One aliquot was assayed immediately and the others were frozen at either -20 degrees C or -70 degrees C. The activity of factor VIII and the concentration of von Willebrand factor antigen were measured after one week and one, two, three, four, five, six, eight and 10 months of storage. There were minor changes in both variables, particularly after four months, resulting in a decrease in the activity of factor VIII and an increase in the concentration of von Willebrand factor antigen. The changes were more pronounced at -20 degrees C. However, both factors remained relatively stable for the whole period.

Hemolytic transfusion reactions in a dog with an alloantibody to a common antigen

Alloantibodies to high-frequency red cell antigens, defined as inherited traits occurring in 92% to 99% or more of the general population, are recognized as a cause of hemolytic transfusion reactions in humans. Here we describe a dog (dog erythrocyte antigen [DEA] 1.2- and DEA 4-positive) sensitized by prior blood transfusion, for which a compatible blood donor could not be found; transfusion of DEA 1.1-negative blood resulted in hemolytic transfusion reactions. Patient serum from days 1 (before first transfusion) and 16 was available for further testing; using 4 dogs with different blood types as potential donors, the major crossmatches were compatible using serum from day 1. However the crossmatches were all incompatible with serum from day 16, indicating that the patient was sensitized to an antigen after the first transfusion. The presence of an alloantibody against DEA 1.1 was not ruled out in this patient, but the incompatibility reactions of patient serum with red cells from donors negative for DEA 1.1 indicated that an alloantibody against a red cell antigen other than DEA 1.1 or any other known DEA for which typing reagents were available (DEA 3, 5, and 7) was present. Subsequently, red cells from 1 of the patient's siblings (DEA 1.2-, 4-, and 7-positive) were found not to agglutinate when incubated with patient's serum from day 16, ruling out the presence of an anti-DEA 7 antibody, and suggesting that an alloantibody against a common red cell antigen missing in the patient and sibling was responsible for the blood incompatibility reactions.(ABSTRACT TRUNCATED AT 250 WORDS)