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

Cytokine Adsorption as an Adjunctive Treatment for Patients with Immune-Mediated Hemolytic Anemia Receiving Therapeutic Plasma Exchange: A Case Series of 3 Dogs

The use of cytokine adsorption is an emerging treatment for inflammatory diseases in human medicine. There are few reports of this treatment modality in veterinary medicine and no reports of the use of a cytokine adsorbent for immune-mediated hemolytic anemia (IMHA). These case reports illustrate the use of a cytokine adsorbent as an adjunctive treatment during therapeutic plasma exchange (TPE). All dogs were unresponsive to conventional treatment or were severely affected by rapid hemolysis of red blood cells. The aim was to treat all dogs with three sequential TPE sessions; however, one dog died before completion of three sessions and one dog required additional sessions. Preliminary evidence indicates that the use of a cytokine adsorption is well tolerated and can be considered as an adjunct in the management of IMHA that is severe or refractory to traditional treatment.

Centrifugal therapeutic plasma exchange in dogs with immune-mediated hemolytic anemia (2016-2018): 7 cases

OBJECTIVE

To describe the technique of centrifugal therapeutic plasma exchange (cTPE) in dogs diagnosed with immune-mediated hemolytic anemia (IMHA) and summarize the outcome of the procedure.

DESIGN

Retrospective review of cTPE performed at North Carolina State University from 2016 to 2018, through a search of the institutional database for cTPE and IMHA.

SETTING

University teaching hospital.

ANIMALS

Seven dogs with confirmed IMHA were presented to a university teaching hospital ICU for cTPE. Six dogs were not responsive to standard medical management with immunosuppressive agents, while 1 dog presented before immunosuppressive agents were begun.

INTERVENTIONS

All dogs underwent multiple cTPE procedures using 1 of 2 commercially available apheresis systems.

MEASUREMENTS AND MAIN RESULTS

At presentation, the median HCT was 0.15 L/L (15.7%) (range, 0.10-0.19 L/L [10.3%-19%]) and the median total serum bilirubin was 32.5 mmol/L (1.9 mg/dl) (range, 15.4-597 mmol/L [0.9-34.9 mg/dl]). The median number of transfusions before cTPE was 1 (range, 1-4), with a median total of infused RBCs of 12.9 ml/kg (range, 8.8-37 ml/kg). cTPE with an exchange of ≥4 times total plasma volumes was used to decrease the level of circulating autoreactive antibodies. The median total plasma volumes exchanged was 4.5 times (range, 2.5-6.5 times) over 2-4 procedures. Anticoagulation was performed using a combination of systemic heparinization and regional citrate in all dogs. Six of 7 dogs (85.7%) were discharged from the hospital and were alive 90 days after discharge. One dog (14%) did not respond to cTPE (∼6.5 times total plasma volume exchanged) and was euthanized.

CONCLUSIONS

cTPE is a feasible and relatively safe bridging treatment option for the management of canine IMHA.

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.

Association of Veterinary Hematology and Transfusion Medicine (AVHTM) Transfusion Reaction Small Animal Consensus Statement (TRACS) Part 2: Prevention and monitoring

OBJECTIVE

To systematically review available evidence to develop guidelines for the prevention of transfusion reactions and monitoring of transfusion administration in dogs and cats.

DESIGN

Evidence evaluation of the literature (identified through Medline searches through Pubmed and Google Scholar searches) was carried out for identified transfusion reaction types in dogs and cats. Evidence was evaluated using PICO (Population, Intervention, Comparison, Outcome) questions generated for each reaction type. Evidence was categorized by level of evidence (LOE) and quality (Good, Fair, or Poor). Guidelines for prevention and monitoring were generated based on the synthesis of the evidence. Consensus on the final recommendations and a proposed transfusion administration monitoring form was achieved through Delphi-style surveys. Draft recommendations and the monitoring form were made available through veterinary specialty listservs and comments were incorporated.

RESULTS

Twenty-nine guidelines and a transfusion administration monitoring form were formulated from the evidence review with a high degree of consensus CONCLUSIONS: This systematic evidence evaluation process yielded recommended prevention and monitoring guidelines and a proposed transfusion administration form. However, significant knowledge gaps were identified, demonstrating the need for additional research in veterinary transfusion medicine.

Association of Veterinary Hematology and Transfusion Medicine (AVHTM) transfusion reaction small animal consensus statement (TRACS). Part 3: Diagnosis and treatment

OBJECTIVE

To systematically review available evidence to develop guidelines for diagnosis and treatment of transfusion-associated reactions in dogs and cats.

DESIGN

Standardized and systemic evaluation of the literature (identified through Medline via PubMed and Google Scholar searches) was carried out for identified transfusion reaction types in dogs and cats. The available evidence was evaluated using PICO (Population, Intervention, Comparison, Outcome) questions generated for each reaction type. The evidence was categorized by level of evidence (LOE) and quality (Good, Fair, or Poor). Guidelines, diagnostic, and treatment algorithms were generated based on the evaluation of the evidence. Consensus on the final guidelines was achieved through Delphi-style surveys. Draft recommendations were disseminated through veterinary specialty listservs for review and comments, which were evaluated and integrated prior to final publication.

RESULTS

Medline via PubMed and Google Scholar databases were searched. There were 14 Population Intervention Comparison Outcome questions identified and corresponding worksheets were developed focusing on the diagnosis and treatment of transfusion-associated reactions in dogs and cats. Fourteen guidelines and four algorithms were developed with a high degree of consensus.

CONCLUSIONS

This systematic evidence evaluation process yielded recommended diagnostic and treatment algorithms for use in practice. However, significant knowledge gaps were identified, demonstrating the need for additional research in veterinary transfusion medicine.

Extracorporeal Therapies in the Emergency Room and Intensive Care Unit

Extracorporeal treatments create opportunity for removing disease causing solutes within blood. Intoxications, renal failure, and immune-mediated diseases may be managed with these treatments, often providing new hope for patients with severe or refractory disease. Understanding solute pharmacokinetics and the limitations of each type of extracorporeal technique can allow for the selection of the optimal treatment modality.

Therapeutic Strategies for Treatment of Immune-Mediated Hemolytic Anemia

Immune-mediated hemolytic anemia is a common hematologic disorder in dogs. Disease management involves immunosuppression using glucocorticoids, potentially in combination with other medications such as azathioprine, cyclosporine, or mycophenolate mofetil. Therapeutic drug monitoring may enhance the utility and maximize the safety of cyclosporine and mycophenolate mofetil. The disease is proinflammatory and prothrombotic. Antithrombotic drug administration is therefore essential, and anticoagulant therapy should be initiated at the time of diagnosis. Additional therapies include red blood cell transfusion to support blood oxygen content. Future therapies may include therapeutic plasma exchange, anti-CD20 monoclonal antibodies, and complement inhibitors.

Application of therapeutic plasma exchange in dogs with immune-mediated thrombocytopenia

Therapeutic plasma exchange (TPE) is an emerging treatment for dogs with immune-mediated diseases, but reports for treatment of immune-mediated thrombocytopenia (IMT) are lacking. These case reports illustrate the application of centrifugal TPE in 4 dogs with IMT. All dogs presented with severe hemorrhage requiring ≥1 blood transfusions, were unresponsive to conventional treatment or both. Dogs were treated with 3 sequential centrifugal TPE sessions, totaling 4.0 to 4.9 total plasma volumes exchanged per dog. In 3 dogs, TPE was associated with improvement in clinical manifestations of bleeding and platelet count in combination with immunosuppressive drugs. One dog was euthanized after 3 treatments because of persistent severe thrombocytopenia and hemorrhage. Preliminary observations indicate that TPE is safe and may be a useful adjunct in the management of IMT that is severe or refractory to traditional treatment.

Successful management of clinical signs associated with hepatic encephalopathy with manual therapeutic plasma exchange in a dog

OBJECTIVE

To describe the use of manual therapeutic plasma exchange (TPE) to manage hepatic encephalopathy (HE) in a dog.

CASE SUMMARY

A 9-year-old neutered female Dachshund presented for HE secondary to a previously diagnosed portosystemic shunt. The hyperammonemia and severe clinical signs of HE persisted despite extensive medical management. Therapeutic plasma exchange was performed for stabilization prior to surgical shunt ligation. A total of 1 plasma volume was processed during a single manual TPE session. The ammonia immediately prior to TPE was 235 μmol/L (reference interval, 10-30 μmol/L) and decreased to 117 μmol/L by the end of the session. The dog showed significant improvement in clinical signs shortly after the session and remained stable thereafter. Shunt ligation was performed 5 days later with no complications observed with TPE or postoperatively. The dog was discharged 3 days after surgery with no neurological signs and was doing well 100 days after surgery.

NEW OR UNIQUE INFORMATION PROVIDED

To the authors' knowledge, this is the first published report of manual TPE to manage HE in veterinary medicine. Therapeutic plasma exchange should be further investigated as a possible strategy to manage clinical signs of HE in patients that are refractory to medical management. Achieving this with manual TPE may be considered in patients that are too small for conventional TPE due to extracorporeal volume or in situations where conventional TPE is not available.

Membrane-based therapeutic plasma exchange in dogs: Prescription, anticoagulation, and metabolic response

BACKGROUND

Therapeutic plasma exchange (TPE) is used increasingly in small animals to remove circulating large molecular products such as antibodies, pathogenic proteins, and protein-bound toxins. Specific, efficient, and safe protocols need to be developed.

HYPOTHESIS/OBJECTIVES

To describe the technique of membrane-based TPE, the resulting physiological and metabolic changes, and to define an adequate regional citrate anticoagulation protocol.

ANIMALS

Thirty-four dogs treated with TPE (2011-2017).

METHODS

Retrospective review of all TPE treatments performed at the Vetsuisse Faculty, University of Bern, identified through a search of the institutional database for extracorporeal treatments.

RESULTS

Sixty-four treatments were performed, resulting in 1.0 plasma volume exchange (range, 0.4-1.1). Replacement fluids included fresh frozen plasma (12%-100% volume), colloids (0%-52%), human albumin (0%-41%), and saline (0%-70%). Anticoagulation was performed with regional citrate (n = 24), systemic heparinization (n = 2), or combined (n = 38). Main relevant laboratory changes included a 24.7% decrease in total proteins (interquartile range, 16.7-31.4; P < .001), 53% in fibrinogen (-30 to 63; P = .009), 36% in bilirubin (13-43, P = .02), 9.0% in urea (0.7-15.7; P < .001), and 4.5% in creatinine (-6.6 to 10.6; P = .006). Citrate accumulation was evidenced in all dogs, more pronounced in those with renal but not with hepatic impairment. Maximal tolerable citrate rates were estimated as 5.5 and 9.0 μmol/kg/min for treatments in dogs with and without renal impairment, respectively. Complications were observed in 22 treatments (34%) and were fatal in 2 dogs.

CONCLUSIONS AND CLINICAL IMPORTANCE

Therapeutic plasma exchange causes metabolic and biochemical alterations. Understanding these effects makes possible to anticipate most complications and to improve safety of the procedure.

Use of therapeutic plasma exchange to treat nonsteroidal anti-inflammatory drug overdose in dogs

Background

Therapeutic plasma exchange (TPE) may be an effective technique for treatment of accidental nonsteroidal anti‐inflammatory drug (NSAID) overdose, but information regarding the use of this technique in veterinary medicine is currently limited.

Objectives

To evaluate the overall outcome for dogs with NSAID overdose treated with TPE and to determine if any presenting factors can predict or influence overall outcome. Secondary objectives included investigating TPE complications as well as the utility of other adjunctive treatments.

Animals

Eleven client‐owned dogs presented for NSAID overdose that received TPE. All patients also received additional supportive treatment including IV lipid infusion.

Methods

Retrospective review of medical records.

Results

Eleven cases were included in the study. Of these, the NSAID ingested was ibuprofen in 6 (54.5%), naproxen in 4 (36.4%), and deracoxib in 1 (9.1%). All dogs survived to discharge with 3 (27.3%) developing acute kidney injury during hospitalization. A larger initial dose of NSAID ingested was associated with a higher maximum serum creatinine concentration during hospitalization (P = .04) and larger change in serum creatinine concentration from baseline (P = .02). Six dogs (54.5%) developed complications associated with TPE. The use of other treatments did not affect the overall outcome.

Conclusions and Clinical Importance

We identified TPE as an effective treatment for NSAID overdose with good outcomes despite high doses of NSAID ingestion in dogs treated with a single TPE treatment. Complications were common but did not affect the final outcome. Therapeutic plasma exchange should be considered in patients presenting for high‐dose NSAID ingestion.

Double filtration plasmapheresis in the treatment of hyperproteinemia in dogs affected by Leishmania infantum

Three dogs were evaluated for severe hyperproteinemia and hyperglobulinemia secondary to Leishmania infantum. Double filtration plasmapheresis (DFPP) was performed in two dogs at days 1, 2, and 6 after presentation. The third dog received DFPP at days 1 and 3 after presentation and eleven hemodialysis treatments. Significant reduction in serum total protein (p < 0.0001), alpha-1 (p = 0.023), alpha-2 (p = 0.018), gamma globulins (p = 0.0105), and a significant increase in albumin/globulin ratio (p = 0.0018) were found. DFPP may be a promising therapeutic technique for rapid resolution of signs of hyperproteinemia in dogs affected by L. infantum.

Description of the Use of Plasma Exchange in Dogs With Cutaneous and Renal Glomerular Vasculopathy

Cutaneous and renal glomerular vasculopathy (CRGV) is a rare disease affecting dogs, with a recent apparent increase in prevalence since 2012 in the UK. This disease is characterized by a vasculopathy affecting small vessels of the kidney and skin, leading to thrombotic microangiopathy. The underlying etiology remains unknown although clinicopathological and histological findings resemble features of certain forms of thrombotic microangiopathy in people, for which plasma exchange (PEX) is considered an important component of therapy. The objective of the present study is to describe the use of PEX as adjunctive treatment in dogs diagnosed with CRGV. A retrospective review of dogs diagnosed with CRGV between 2014 and 2016 treated with PEX was performed. Clinical records were reviewed and data relating to signalment, diagnostic tests and management strategies were summarized. Information and complications relating to PEX were recorded. Six dogs were diagnosed with CRGV (n = 2 ante-mortem, n = 4 post-mortem) and underwent PEX as part of their therapy. All dogs had cutaneous lesions and were azotemic with oliguria or anuria. All dogs underwent at least one PEX cycle; one dog had a single cycle PEX, three dogs two cycles PEX, and two dogs had one cycle PEX and one cycle of prolonged intermittent renal replacement treatment. Complications seen during PEX therapy included hypothermia (n = 4), tachycardia (n = 2), hypotension (n = 2), and hypocalcemia (n = 6). Two dogs survived to discharge, the remaining four dogs were euthanized. The positive outcome in two dogs treated with PEX despite the reported high mortality rate once acute kidney injury with oliguria/anuria occurs does not confirm success of this treatment. However, survival in two dogs that were initially oligoanuric highlights that further consideration and evaluation of PEX for this patient group is warranted for this specific disease. Additional studies are urgently needed to identify the underlying etiology of CRGV before more targeted therapies can be developed. Based on our findings, further evaluation of the role of PEX in this specific disease are warranted.

Treatment of carprofen overdose with therapeutic plasma exchange in a dog

OBJECTIVE

To report the use of therapeutic plasma exchange (TPE) in a dog with carprofen toxicosis.

SUMMARY

A 6-year-old female neutered Bichon Frise weighing 6.9 kg was examined after it had ingested 72 mg/kg carprofen. Mild dehydration without azotemia and with a urine specific gravity of 1.050 was noted at presentation. Treatment consisted of induction of emesis, symptomatic medical therapy, and TPE. The TPE achieved 1.5 plasma volume exchanges over 3 hours. Blood samples and effluent samples were collected every 30 minutes during TPE and additional blood samples were collected 11 and 35 hours after treatment. Carprofen concentrations in these samples were determined by high-pressure liquid chromatography. A 51% reduction in serum carprofen concentration was achieved following TPE.

NEW OR UNIQUE INFORMATION PROVIDED

This report describes the successful reduction of plasma carprofen concentration in a dog using TPE. Although recent studies suggest that this particular dog may not have received a toxic dose, a 51% reduction of plasma carprofen concentration was achieved over 180 minutes, and TPE may be beneficial for treatment of dogs that have ingested higher doses.

The use of therapeutic plasma exchange to reduce serum bilirubin in a dog with kernicterus

OBJECTIVE

To describe the use of a manual method of therapeutic plasma exchange to reduce total serum bilirubin, manage kernicterus, and halt progression of neurological dysfunction in a dog with immune-mediated hemolytic anemia (IMHA).

CASE SUMMARY

A 5-year-old male neutered Lhasa Apso diagnosed with IMHA developed acute onset neurologic signs consistent with kernicterus. Manual therapeutic plasma exchange was performed in an attempt to reduce total serum bilirubin. The initial exchange was performed at a lower plasma exchange volume due to the dog's critical status and the dog's clinical signs progressed. More aggressive plasma exchange was performed that resulted in a reduction in total serum bilirubin and no further progression of neurologic signs. The dog was euthanized due to suspicion of permanent neurologic changes and need for further blood transfusions. Histopathology postmortem confirmed a diagnosis of kernicterus.

NEW OR UNIQUE INFORMATION PROVIDED

Kernicterus secondary to hyperbilirubinemia is well described in people, but has rarely been reported in dogs. Therapeutic plasma exchange has been used for decades in people to rapidly decrease serum bilirubin when hyperbilirubinemia progresses to neurologic signs, but to the authors' knowledge this has not been described in a dog.

Treatment of meloxicam overdose in a dog via therapeutic plasma exchange

OBJECTIVE

To describe the treatment of a meloxicam overdose in a dog with therapeutic plasma exchange (TPE).

CASE SUMMARY

A 6-month-old female Bulldog, presented for routine laparoscopic ovariectomy. Postoperatively the dog received an accidental overdose of meloxicam (1 mg/kg IV [intravenously]). The patient was treated with supportive medical therapy and TPE over 210 minutes achieving 1.2 plasma volume exchanges. During therapy, heparinized blood and effluent samples were collected. Meloxicam concentrations were determined in the samples by high pressure liquid chromatography. Post TPE, the dog continued to receive supportive medical therapy and was discharged 48 hours after the overdose. The dog remained asymptomatic for meloxicam intoxication. Follow-up rechecks at 1 and 6 weeks were unremarkable with no further treatment required.

NEW OR UNIQUE INFORMATION

This report describes the successful use of TPE adjunctively following an acute meloxicam overdose. An 82% reduction of plasma meloxicam concentration was achieved over 210 minutes. Twenty-four hours after therapy, a 47% sustained reduction of plasma meloxicam was measured after redistribution of drug between body compartments.

Canine autoimmune hemolytic anemia: management challenges

Immune-mediated hemolytic anemia is one of the most common manifestations of canine immune-mediated disease, yet treatment regimens remain nonstandardized and, in some cases, controversial. The main reason for this, as for most diseases in veterinary medicine, is the lack of large-scale placebo-controlled trials so that the efficacy of one treatment over another can be established. Most of the evidence used for treatment comes from retrospective studies and from personal preference and experience, and because of this, treatment regimens tend to vary among institutions and individual clinicians. Management of immune-mediated hemolytic anemia includes immunosuppression, thromboprophylaxis, and supportive care measures to help prevent and treat concurrent conditions.

Myasthenia gravis in dogs with an emphasis on treatment and critical care management

OBJECTIVE

To review the human and veterinary literature on the pathophysiology of myasthenia gravis (MG) and describe treatment options for clinical use in people and animals.

DATA SOURCES

Human and veterinary clinical reports, studies and reviews, textbooks, and recent research findings in MG from 1996 present, with a focus on treatment and patient management.

HUMAN DATA SYNTHESIS

MG is a well-described condition in people with new research and treatment options available. Many of the newest therapeutic options available in veterinary medicine for MG are based on current strategies used in people with this condition. Seronegative MG is well described in people and provides insight to clinical cases encountered in veterinary medicine when the index of suspicion is high though serologic tests are negative.

VETERINARY DATA SYNTHESIS

Previous studies in veterinary medicine focused on the use of acetylcholinesterase inhibitors as the main form of treatment in canine MG. Recent studies, mainly case series and case reports, emphasize the use of immunomodulatory treatments as an alternative for long-term treatment. However, there are no randomized, controlled studies on treatment with immunomodulatory therapy for MG in dogs available to assess the efficacy of this treatment strategy.

CONCLUSIONS

Although early recognition of clinical signs is most important in the outcome of patients with MG, further understanding the pathophysiology of MG may lead to earlier diagnosis and novel treatment strategies. The discovery of additional autoantibodies against striated muscle proteins in dogs, should enhance our understanding of diseases affecting the neuromuscular junction. In addition, clinical data for canine MG could be applied to other autoimmune disorders.