Ultrastructural changes in the liver of cats with lipidosis on the background of anti-cytokine therapy

Abstract

The data on the ultrastructure of the liver of cats with steatosis during therapy with Actemra drug is discussed. Sick cats of the age 6-10 years were divided into 2 groups, and the standard treatment and Royal Canin Hepatic food for 30 days was prescribed. The stages of treatment of the cats in the 2nd trial group included Actemra drug. The Actemra drug (or) is a recombinant humanized monoclonal antibody to IL-6 human receptor from the subclass of IgG1 immunoglobulin. Tocilizumab binds to both soluble and membrane IL-6 receptors and suppresses them. The preclinical studies on laboratory animals did not reveal any carcinogenic, teratogenic or mutagenic properties of Actemra. The treatment efficacy, along with the study of the clinical status and morpho-biochemical indices, was also evaluated based on the results of ultrastructural changes in the liver. The preparation of histology specimens included intravital liver biopsy, fixation, processing, embedding of pieces of material and preparation of sections, staining with hematoxylin and eosin and embedding of sections. On the clinic visit, the signs of liver steatosis were detected in all sick cats. In healthy cats, the liver had a homogeneous parenchyma with preservation of the beam structure. After 60 days from the beginning of treatment, there was no dynamics in regression of pathological changes in the liver in cats of the 1st trial group. In two cats (40%), morphological changes characteristic of steatohepatitis and liver fibrosis were observed in the liver, and in three cats (60%), manifestation of fatty hepatosis was revealed. In all cats of the 2nd trial group, morphological changes in the liver were characterized by reversible signs of fatty and granular dystrophy. Pathological forms of hepatocytes accounted for about 10% of the total number in the field of vision of the microscope. Based on the above, it follows that the Actemra drug promotes liver regeneration reducing the severity of symptoms of liver steatosis.