[Use of human intravenous immunoglobulin in dogs with primary immune mediated hemolytic anemia]

The use of high-dose immunoglobulin M-enriched human immunoglobulin in dogs with immune-mediated hemolytic anemia

BACKGROUND

The IV use of human immunoglobulin (hIVIG) in dogs with primary immune-mediated hemolytic anemia (IMHA) has been described previously, but herein we describe the use of high-dose IgM-enriched hIVIG (Pentaglobin).

HYPOTHESIS/OBJECTIVES

Dogs treated with high-dose Pentaglobin will experience shorter time to remission and hospital discharge and have decreased transfusion requirements compared to dogs receiving standard treatment alone.

ANIMALS

Fourteen client-owned dogs diagnosed with primary IMHA at specialist referral hospitals in the United Kingdom.

METHODS

All prospectively enrolled dogs received prednisolone, dexamethasone or both along with clopidogrel. Patients were randomized to receive Pentaglobin at 1 g/kg on up to 2 occasions, or to serve as controls. No additional immunosuppressive drugs were allowed within the first 7 days of treatment. Remission was defined as stable PCV for 24 hours followed by an increase in PCV.

RESULTS

Ten of 11 dogs from the treatment group and 2 of 3 dogs from the control group achieved remission and survived until hospital discharge. Survival and time to remission were not significantly different between groups. The volume of packed red blood cells transfused, normalized for body weight, was not significantly different between groups. Potential adverse reactions to Pentaglobin occurred in 2 dogs, but their clinical signs may have been related to the underlying disease.

CONCLUSIONS AND CLINICAL IMPORTANCE

Treatment with high-dose Pentaglobin was well tolerated by dogs with primary IMHA but no significant advantage was found in this small study. Additional studies examining larger groups and subpopulations of dogs with primary IMHA associated with a poorer prognosis are warranted.

Use of Human Intravenous Immunoglobulin in Veterinary Clinical Practice

Therapy with human intravenous immunoglobulin (hIVIG) as an immunomodulator in veterinary patients results in effective but transient immunosuppression, and may be viable as part of a multidrug strategy against immune-mediated thrombocytopenia and autoimmune cutaneous disease. Efficacy of hIVIG against other veterinary autoimmune diseases is questionable. Veterinary patients tolerate hIVIG therapy well, with few infusion reactions documented. Veterinary clinical trials of hIVIG are limited, and more work is needed to determine the true efficacy and risk of hIVIG administration in companion animals.

Evaluation of membrane-based therapeutic plasma exchange as adjunctive treatment for immune-mediated hematologic disorders in dogs

Background

Therapeutic plasma exchange (TPE) has been used increasingly to treat immunological diseases in dogs, although data concerning its efficacy are lacking.

Hypothesis/Objectives

To describe the clinic and the outcome of dogs with immune‐mediated hematological disorders (IMHD) treated with membrane filtration TPE.

Animals

One hundred forty‐six dogs diagnosed with IMHD, including 17 dogs treated with and 129 control dogs treated without TPE.

Methods

Retrospective study of cases selected with a search of all medical records for dogs diagnosed with IMHD (2010‐2019). Primary outcomes included the assessment of safety and efficacy of adjunctive TPE compared to medical treatment alone.

Results

The TPE group included 7 dogs with immune‐mediated hemolytic anemia (IMHA), 5 dogs with immune‐mediated thrombocytopenia (IMT), and 5 dogs with combined IMHA‐IMT; the control group included 63 dogs with IMHA, 47 dogs with IMT, and 19 dogs with IMHA‐IMT. Dogs treated with TPE were more often refractory to initial immunosuppression (71%) than controls (43%; P = .04). Complications were observed in 15/43 TPE treatments (35%). The response rate of dogs treated with TPE was 83% in IMHA (controls, 65%; P = .5) and 80% in IMT (controls, 70%; P = .71). Overall, 12/17 dogs (71%) treated with TPE reached complete remission, 2/17 (12%) partial remission, and 3/17 (18%) died or were euthanized. Eighty‐two percent of the dogs treated with TPE survived to discharge (controls, 69%; P = .4).

Conclusions and Clinical Importance

Despite a bias toward dogs refractory to initial immunosuppression, dogs treated with adjunctive TPE had a similar outcome as dogs treated medically.

Two cases of acute polyradiculoneuritis in dogs consuming a raw poultry diet

A 9-year-old female mixed-breed dog presented with ascending flaccid tetraparesis, and a 5-year-old castrated male Poodle dog presented with ventroflexion of neck, dysphonia, and hindlimb weakness, which progressed to acute ascending tetraparesis. Both dogs were fed raw poultry for over 9 and 5 years, respectively. Blood examination and other test results were normal or unrelated to the present case. Fecal polymerase chain reaction analysis in the Poodle dog was positive for Clostridium perfringens and Campylobacter jejuni. Tetraparesis improved with supportive care in both dogs. Human IV immunoglobulin was only administered to the Poodle dog, which showed a shorter recovery (12 days compared to 34 days in the mixed-breed dog). Both dogs returned to normal conditions eventually.

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.

ACVIM consensus statement on the treatment of immune-mediated hemolytic anemia in dogs

Immune‐mediated hemolytic anemia (IMHA) causes severe anemia in dogs and is associated with considerable morbidity and mortality. Treatment with various immunosuppressive and antithrombotic drugs has been described anecdotally and in previous studies, but little consensus exists among veterinarians as to the optimal regimen to employ and maintain after diagnosis of the disease. To address this inconsistency and provide evidence‐based guidelines for treatment of IMHA in dogs, we identified and extracted data from studies published in the veterinary literature. We developed a novel tool for evaluation of evidence quality, using it to assess study design, diagnostic criteria, explanation of treatment regimens, and validity of statistical methods. In combination with our clinical experience and comparable guidelines for humans afflicted with autoimmune hemolytic anemia, we used the conclusions of this process to make a set of clinical recommendations regarding treatment of IMHA in dogs, which we refined subsequently by conducting several iterations of Delphi review. Additionally, we considered emerging treatments for IMHA in dogs and highlighted areas deserving of future research. Comments were solicited from several professional bodies to maximize clinical applicability before the recommendations were submitted for publication. The resulting document is intended to provide clinical guidelines for management of IMHA in dogs. These guidelines should be implemented pragmatically, with consideration of animal, owner, and veterinary factors that may vary among cases.

Clinical course of acute canine polyradiculoneuritis following treatment with human IV immunoglobulin

Treatment of dogs with acute canine polyradiculoneuritis (ACP) is restricted to physical rehabilitation and supportive care. In humans with Guillain-Barré syndrome, the counterpart of ACP, randomized trials show that IV immunoglobulin (IVIg) speeds recovery. The authors of the current study hypothesized that dogs with ACP would tolerate IVIg well and recover faster than dogs managed with supportive treatment only. Sixteen client-owned dogs with ACP were treated with IVIg, and 14 client-owned dogs served as a retrospective control group. Diagnosis was confirmed using clinical features, electrodiagnostics, cerebrospinal fluid analysis, and muscle/nerve biopsies. The duration of the initial progressive phase, the time from IVIg administration until the dogs were ambulating without assistance, and the duration of the complete episode were evaluated. Adverse reactions (anaphylaxis, mild hematuria) were observed in two dogs. Dogs treated with IVIg were ambulating without assistance after a median of 27.5 days (range, 15-127 days) from onset of clinical signs. The control group was ambulatory without assistance at a median of 75.5 days (range, 5-220 days). Even though this result is not statistically significant, there is a clear trend toward faster recovery in dogs treated with IVIg.

A review of current indications, adverse effects, and administration recommendations for intravenous immunoglobulin

OBJECTIVE

To review and summarize the body of literature regarding human intravenous immunoglobulin (hIVIG) therapy in veterinary medicine. Mechanism of action, usage in human medicine, adverse effects of therapy, implications for veterinary use, and administration recommendations are discussed.

DATA SOURCES

Current human and veterinary peer-reviewed medical literature including original research articles and scientific reviews.

HUMAN DATA SYNTHESIS

There are currently 6 labeled uses for hIVIG in human medicine, but preparations are used off-label to successfully treat multiple immune-mediated conditions. To maximize the potential of hIVIG use in animals and identify areas deficient in research, a review of the current literature is warranted.

VETERINARY DATA SYNTHESIS

Investigation of hIVIG therapy in veterinary patients has been limited to the subjects of immune-mediated hemolytic anemia (IMHA), immune-mediated thrombocytopenia (ITP), Evan's syndrome, cutaneous disease, myasthenia gravis (MG), and sudden acquired retinal degeneration (SARDS). Proponents of veterinary hIVIG use believe administration may reduce transfusion requirements and decrease hospitalization time.

CONCLUSION

Immunoglobulin (Ig) has not been shown to decrease transfusion requirements in IMHA patients, but shows great promise for treatment of ITP and dermatological diseases. Although serial transfusion of hIVIG is employed in human medicine, repeated transfusion is not recommended in animals due to risk of severe allergic reaction. Other potential adverse effects of transfusion include delayed hypersensitivity reactions, thromboembolism, renal failure, hypotension, and aseptic meningitis.

Immune-mediated hemolytic anemia: understanding the nemesis

IMHA is one of the most common causes of anemia in small animals. Although treatment may be rewarding, many patients do not respond adequately to glucocorticoids alone and require additional immunosuppressive therapy. Some patients may succumb to acute severe anemia and die within the first few weeks of treatment; even if they survive, relapses may occur. IMHA is the nemesis; as our understanding of this disease increases and treatment options expand, it is hoped that survival rates will finally improve.