Spondyloarthropathy in gorillas

Following comprehensive characterization of the temporomandibular joint (TMJ) of the California sea lion, as well demonstrating that TMJ-osteoarthritis (OA) occurs in this species, the objective of this part of the investigation was to describe the macroscopic osteologic findings associated with TMJ-OA in a large museum collection of skull specimens.

Museum skull specimens (n = 497) of California sea lions were examined macroscopically according to defined criteria for the presence, severity, location and characteristics of TMJ-OA. The specimens, acquired from strandings, varied in age from young adults to mature adults.

Overall 63.5% of the specimens had findings consistent with TMJ-OA. Of these, 56.2% were from females 43.8% were from males. Moreover, 71.2% specimens were from mature adults and 28.8% from young adults. However, there was no significant association between age and sex with the presence or severity of TMJ-OA. The most prominent TMJ-OA changes were the presence of subchondral bone defects and abnormal porosity. The majority of the OA present at the mandibular head affected the entire articular surface. In contrast, the OA present on the mandibular fossa of the temporal bone was located primarily on the medial aspect (P < 0.001).

The incidence of TMJ-OA in California sea lions is high and varies in severity. Although the significance of the high incidence of this disease in the California sea lion remains elusive, the occurrence and severity of TMJ-OA detected in this study may play an important role in the species’ morbidity and mortality.

Autoimmune diseases represent a group of immune-mediated inflammatory disorders that are driven by an unwanted hyperactivity of the immune system. The prevalence of the different types of autoimmune disease differs, but collectively they affect between 15 and 25 million individuals in the USA. They are often characterized by chronic inflammation, which can either be systemic or confined to one of a few organs. The chronic inflammation can lead to a spectrum of mild to severe clinical conditions depending on the organ/system targeted by the autoimmune response. The chronic nature of autoimmune diseases and the often invalidating consequences result not only in personal tragedy but also high medical and socioeconomic costs. The common marmoset is prone to a naturally occurring inflammatory condition called Marmoset Wasting Syndrome. Lentivirus infection leads to a general dysfunction of the immune system in humans (human immunodeficiency virus, HIV) and in rhesus monkeys (simian immunodeficiency virus, SIV). The immune dysregulation leads to the production of autoantibodies and autoimmune responses contributing to the pathogenesis of acquired immune deficiency syndrome (AIDS). Experimental autoimmune encephalomyelitis in nonhuman primates is used as a preclinical model of multiple sclerosis. The rhesus monkey model of collagen-induced arthritis (CIA) was originally developed as a preclinical model of rheumatoid arthritis in adults.