Immunoglobulin A monoclonal gammopathy in two horses with multiple myeloma.

The research article discusses two clinical cases of horses diagnosed with a form of bone marrow cancer known as multiple myeloma, which had led to a unique concentration of a type of antibody (Immunoglobulin A) in their blood and urine.

Observations and Clinical Findings

• The researchers observed that the affected horses exhibited non-specific symptoms. These were general signs that could often be associated with many different conditions, making it challenging to determine the exact disease.
• These symptoms included weight loss, pale mucous membranes, limb swelling (edema), and bacterial respiratory tract infection.

Laboratory Test Results

• Frequent laboratory abnormalities included hyperproteinaemia, a condition characterized by abnormally high concentrations of total protein in the blood.
• Hyperglobulinaemia was also common, an increase in the number of specific proteins (globulins).
• The horses also had hypoalbuminaemia, a lower-than-normal level of albumin in the blood, and high calcium levels in their blood (hypercalcaemia).

Diagnosis and Identification

• The definitive diagnosis of multiple myeloma was established based on the presence of Immunoglobulin A (IgA) monoclonal gammopathy, an abnormal growth of a specific type of white blood cell that leads to the production of a single type of antibody (IgA).
• This gammopathy was detected in both the serum and urine of these horses.
• The researchers also noted an excessively high number of plasma cells in the bone marrow, a condition known as bone marrow plasmacytosis. For a diagnosis of multiple myeloma, this count needs to be greater than 10%.

Outcomes

• One of the horses was euthanized due to the severity of its condition. During the postmortem examination, cancerous infiltrates of plasma cells were found in multiple organs, including its kidneys, spleen, liver, bone marrow, heart muscle, and the glands that produce adrenaline (adrenal glands).
• The other horse was treated for bacterial pneumonia and was still alive half a year after being examined initially.