Plasma exchange as a treatment for hyperbilirubinemia in 2 foals with neonatal isoerythrolysis

Alloimmune Conditions in the Neonatal Foal

Alloimmune disorders occur in foals when pregnant mares produce antibodies against antigens on the foal's cells or tissues, and concentrate them within colostrum. Once foals nurse and absorb colostral antibodies, they can develop hematologic or cutaneous manifestations that can occur individually or in combination. These include neonatal isoerythrolysis, a hemolytic anemia directed against factors on the foal's erythrocytes, alloimmune thrombocytopenia when the antibodies are directed against platelet antigens, alloimmune neutropenia when they are directed against neutrophil antigens, and a combination of suspected alloimmune ulcerative dermatitis, neutropenia and thrombocytopenia. Foals can also develop neutrophilic dermatitis which is suspected to be alloimmune.

Feasibility of hemoperfusion using extracorporeal therapy in the horse

Objective

Develop, implement, and monitor for adverse effects of, a novel hemoperfusion therapy in adult horses.

Methods

A prospective, observational feasibility study using three healthy adult horses from the North Carolina State University teaching herd. Health status was determined by physical exam, complete blood count, coagulation panel, and serum biochemistry. Each horse was instrumented with a 14 Fr × 25 cm double-lumen temporary hemodialysis catheter and underwent a 240 min polymer-based hemoperfusion session. Horses were administered unfractionated heparin to maintain anti-coagulation during the session. Given the novelty of this therapy in horses, each horse was treated as a learning opportunity that informed an iterative process of protocol development and modification.

Measurements and main results

Our long-term goal is to investigate potential clinical applications of hemoperfusion in horses, including cytokine reduction in horses with severe SIRS/sepsis. Horses were monitored for changes in clinical exam, biochemistry and hematology parameters. Additionally, cytokines were quantified to determine whether extracorporeal hemadsorption therapy alone caused an inflammatory response. Our results show that hemoperfusion therapy was associated with decreased platelet counts and serum albumin concentration. There was no significant change in plasma cytokine concentrations with hemoperfusion therapy. In one horse, the cytokine concentrations decreased, as previously reported with hemoperfusion therapy in humans.

Hypothesis

We hypothesized that hemoperfusion therapy could be performed in healthy adult horses without significant adverse effects.

Conclusion

Polymer-based hemoperfusion is a feasible extracorporeal therapy (ECT) modality for adult horses. Additional studies are needed to further establish clinical protocols, as well as establish efficacy of polymer-based hemoperfusion for treatment of various conditions in horses, including intoxications, immune-mediated conditions, and sepsis.

Neonatal hyperbilirubinemia: Background and recent literature updates on the diagnosis and treatment

Hyperbilirubinemia or jaundice has been studied by many researchers because of its diverse causes and potential for toxicity especially in the neonate but to a lesser extent beyond the neonate as well. Several studies have been performed on the normal metabolism and metabolic disorders of bilirubin in last decades of the 20th century. The recent advancement in research and technology facilitated for the researchers to investigate new horizons of the causes and treatment of neonatal hyperbilirubinemia. This review gives a brief introduction to hyperbilirubinemia and jaundice and the recent advancement in the treatment of neonatal hyperbilirubinemia. It reports modifications in the previously used methods and findings of some newly developed ones. At present, ample literature is available discussing the issues regarding hyperbilirubinemia and jaundice, but still more research needs to be done.

Causes of equine perinatal mortality

The peripartum period is critical in equine medicine for maintaining healthy mares, and ensuring the delivery of healthy neonatal foals. The field of perinatal mortality in horses is continuously evolving, with several advances being recently made in causes of perinatal fetal and foal loss. This review details the main causes of perinatal loss in horses, through late pregnancy, parturition and the neonatal period. Recent advances in identification of infectious organisms and indicators of survival in neonatal foals will be discussed. Continued advances in reproductive and neonatal medicine will aid improved survival of foals through fewer pregnancy losses, and improved management of high-risk pregnancies and critically ill neonatal foals.

Therapeutic plasma exchange as adjunct therapy in 3 dogs with myasthenia gravis and myasthenia-like syndrome

OBJECTIVE

To describe the use of therapeutic membrane-based plasma exchange (TPE) for treatment of clinical signs associated with suspected acquired myasthenia gravis (MG) in 3 dogs.

CASE SERIES SUMMARY

Three dogs presented with clinical signs consistent with acquired MG. All 3 dogs were medically managed prior to being treated with TPE. Two of the 3 dogs had increased acetylcholine receptor antibody titers that decreased after TPE. One dog diagnosed with primary MG became clinically normal after 2 sessions of TPE and continued to do well with medical management several months later. The second dog was diagnosed with a suspect thymoma, and TPE was performed as a bridge to surgery, with marked improvement of clinical signs after TPE. The dog was ultimately diagnosed with a thymic carcinoma. The third dog had a positive acetylcholine antibody titer and was ultimately diagnosed with hemangiosarcoma (spleen and liver) and invasive mediastinal thymoma. This dog developed severe pneumonia, was ventilator dependent, and died of multiple organ dysfunction. No immediate complications were observed secondary to TPE. All 3 dogs were concurrently treated with either immunosuppressive agents, anticholinesterase drugs, or both.

NEW OR UNIQUE INFORMATION PROVIDED

The use of TPE in dogs with MG appears to be well tolerated and safe. It may be a reasonable adjunct therapy to acetylcholinesterase drugs in cases that are not responding to medical management alone. Therapeutic plasma exchange might also be considered preoperatively to prevent postoperative complications in dogs with severe MG, although further studies should be performed.

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.