Peripheral neuropathy in cats with inherited primary hyperchylomicronaemia

Area of Science:

• Veterinary Medicine
• Biochemistry
• Genetics

Background:

• Primary hyperlipoproteinaemia, specifically hyperchylomicronaemia, is a lipid metabolism disorder.
• This condition has been observed in a cohort of 20 domestic cats.
• Clinical signs include fasting hyperlipaemia, lipaemia retinalis, and peripheral neuropathies.

Purpose of the Study:

• To describe the clinical and biochemical characteristics of primary hyperlipoproteinaemia in cats.
• To investigate the underlying mechanisms, including lipoprotein lipase activity and lipid distribution.
• To explore the potential genetic basis and pathogenesis of nerve lesions.

Main Methods:

• Clinical examination of affected cats, noting signs like hyperlipaemia and neuropathy.
• Biochemical analysis of plasma triglyceride and cholesterol levels, focusing on lipoprotein fractions.
• Measurement of lipoprotein lipase activity following heparin activation.
• Histopathological examination of affected peripheral nerves to identify lipid granulomata.

Main Results:

• Affected cats exhibited fasting hyperlipaemia with elevated triglyceride and cholesterol, primarily in chylomicrons.
• Significantly reduced lipoprotein lipase activity was observed in affected cats compared to controls.
• Peripheral nerve damage was attributed to lipid granulomata causing nerve compression, often at sites prone to trauma.

Conclusions:

• Primary hyperlipoproteinaemia in cats is characterized by hyperchylomicronaemia and reduced lipoprotein lipase activity.
• The condition is suspected to be inherited as an autosomal recessive trait.
• Lipid granulomata causing peripheral neuropathy are a significant complication, likely exacerbated by physical trauma to nerves.