Provided are thin EPON sections with our unique PAS staining and TEM photomicrographs of patient skeletal muscle with abnormal lysosomes.
Glycogen Storage Diseases are devastating, rare genetic orphan diseases for which there is no cure and treatment regimes are suboptimal. The two most common ones are Von Gierke’s (GSD Type I) and Pompe’s (GSD Type II) disease. Myozyme and Lumizyme are two approved treatments for Pompe’s (Sanofi-Genzyme) that are somewhat effective, but not curative. There are a number of new small companies that are working in this therapeutic area.
Glycogen storage disease type I (GSD I) or von Gierke disease is the most common of the glycogen storage disease, resulting from a deficiency of glucose-6-phosphatase, and has an incidence in the American population of approximately 1 in 50,000 to 100,000 births. The deficiency impairs hepatic production of free glucose from glycogen and from gluconeogenesis. Since these are the two principal metabolic mechanisms of hepatic glucose generation, this causes severe hypoglycemia accompanied by increased glycogen storage in liver and kidneys. Both organs function normally during childhood, but are susceptible to a variety of problems in adult years. Other metabolic derangements include lactic acidosis and hyperlipidemia. Frequent or continuous feedings of cornstarch or other carbohydrates are principal management methods.
Glycogen storage disease type II or Pompe’s disease is an autosomal recessive metabolic disorder which damages muscle and nerve cells throughout the body. It is caused by an accumulation of glycogen in the lysosome due to deficiency of the lysosomal acid alpha-glucosidase enzyme. It is the only glycogen storage disease with a defect in lysosomal metabolism, and the first glycogen storage disease to be identified, in 1932 by the Dutch pathologist J. C. Pompe. The accumulation of glycogen causes progressive muscle weakness (myopathy) throughout the body and affects various body tissues, particularly in the heart, skeletal muscles, liver and nervous system.
Here at CBI we have had the privilege to work with one of our sponsors on a clinical product for a GSD in which we developed unique histopathologic methods and conducted histology, developed a very high quality unique PAS EPON method to stain thin sections of muscle biopsies and conducted transmission electron microscopy with histomorphometry on patient samples. Digital image analysis and histomorphometry was conducted on TEM samples to compare treatment groups. Below are some representative histology, thin sections and TEM of GSD specimens that we prepared and evaluated in our laboratories. We are looking forward to bringing our expertise in the histopathologic evaluation of GSD tissues from both clinical specimens and animal models.