The structure of a leprosy cell is typical of that of Mycobacteria and prokaryotes. Unique to the mycobacteria, the cell wall of leprosy consists of a high amount of lipids. The layer of the cell wall that has to do with the properties of rigidity and shape consists of polysacharide chains crossed by peptide chains. The outer layer of the cell wall in leprosy is composed of a heterogeneous group of peptidoglycolipids or phenolic glycolipids termed mycosides. Leprosy is unique from the Mycobacteria in the composition of its lipids.
Typical mycobacteria fall into four main patterns of their mycolic acid composition.
The mycosides of mycobacteria play an important role in their structure and function as well. The molecules of mycosides often contain combinations of unusual sugars and therefore form unique antigenic determinants. Leprosy contains large amounts of mycosides similar to a certain mycoside A. One of the phenolic glycolipids, phenolic glycolipid-I, is specific for leprosy and a nonoclonal antibody has been produced against it. This unique characteristic aides in leprosy research. It is not totally known whether leprosy is an obligate pathogen, requiring a host to live.