Immune Mediated Neutropenia

Schnauzer

I recently wrote about the concept of immune disease; those disorders where the immune system goes haywire and attacks normal cells in the body. In more recent blog posts, I wrote about two important immune diseases: immune mediated hemolytic anemia (IMHA) and immune mediated thrombocytopenia (ITP or IMTP).  Today’s blog post focuses on a third immune disorder of blood cells: immune mediated neutropenia.

Neutrophils Fight Infection
Neutrophils are the first responders of the immune system. When you get a splinter in your finger, neutrophils rush to the site to start cleaning up bacteria and other nasties. The accumulation of neutrophils in a focal site is known as an abscess. Without neutrophils, the immune system cannot inactivate infectious agents, and patients run the risk of developing a life-threatening systemic infection.

Immune Mediated Neutropenia
Neutropenia is just a fancy way to say a low neutrophil count. Similar to dogs and cats with IMHA and IMT, the immune system of pets with immune mediated neutropenia destroys blood cells, specifically, neutrophils.

Recognizing Immune Mediated Neutropenia
Immune mediated neutropenia is much less common than either IMHA or IMT and is less common in cats than in dogs. A recent study found dogs with immune mediated neutropenia saw their veterinarian because of poor appetite, lethargy or fever, which are all very non-specific clinical findings. A complete blood count is required to identify a low neutrophil count, but if neutropenia is identified, your veterinarian will recommend a battery of tests to evaluate your dog or cat’s low neutrophil count. In addition to immune mediated destruction, low neutrophil counts can result from an infectious disease like ehrlichiosis, a fungal disease such as histoplasmosis or a bone marrow disorder.

Treatment of Immune Mediated Neutropenia
Like the other immune blood cell disorders, initial treatment of dogs and cats with immune mediated neutropenia involves suppressing the immune system with steroids. According to recent research, most dogs with immune mediated neutropenia responded quickly to steroid administration, while a few required additional immunosuppressive agents to correct the neutropenia. While I hope your dog or cat never gets immune mediated neutropenia, the majority of pets diagnosed with this disorder survive for an extended period of time.

One thought on “Immune Mediated Neutropenia”

  1. My 2-year-old cat got immune-mediated neutropenia, immune-mediated hemolytic anemia, and immune-mediated throbocytopenia after receiving both an FeLV vaccination and a Convenia injection on the same day, immediately following a cut on his ear after a cat fight, about 8 months ago. It took at least five days of hospitalization and mega-diagnostics to diagnose, during which time it was not clear that he would make it, having come down with liver failure from the hemolysis, etc. Upon diagnosis, he was finally put on IV steroids and and Atopica, rebounded immediately, and was discharged within 48 hours. However, a month later his neutrophils, which had been increasing rapidly, suddenly took an unexpected nosedive and mycophenolate was added.

    We now think the Atopica was actually the culprit there and it is being withdrawn in fast taper – so far, so good. His myco was also stopped because of severe diarrhea. So far, he is hanging in, and clinically, he’s 100%, except for recently developing chin acne (which is somewhat alarming in light of his immune suppression). His lymphocytes also went too low so I am hoping that withdrawing the meds will solve both that and the (hopefully) cyclosporine-related neutrophil drop.

    It’s been a harrowing ride.

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