Lung Transplantation for Pulmonary Sarcoidosis

Sarcoidosis, a multisystem disorder, results in the production of multiple non-caseating granulomas capable of affecting all organs of the body. It usually occurs in patients between the ages of 10 and 40 years of age in 90% of cases. The prevalence has been reported to be 10-20 per 100,000 in the general population however the annual incidence is 107 per 100,000 (Rybicki, Major et al. 1997). There also appears to be a variation in the racial prevalence of the disease with Caucasians having a 0.85% lifetime risk for the disease while the lifetime risk for Black Americans is 2.5% (Rybicki, Major et al. 1997). The racial implications of the disease are not just confined to prevalence, evidence suggests that along with the increased prevalence of Sarcoidosis Black American patients also have a more acute and severe process in contrast to the usually slow insidious symptoms commonly seen in Caucasian patients (Newman, Rose et al. 1997). Familial clustering has also been identified in linkage studies and this has identified the short arm of chromosome 6 as the area of most interest (Baughman, Lower et al. 2003). Despite intense study an exact etiology for Sarcoidosis has remained elusive for investigators, leaving many to speculate as to the pathogenesis of the disease. Most commonly the respiratory system is the primary target of the disease, in addition to this the skin and eyes are regularly affected leading researchers to believe that an environmental cause was the most likely cause. Many associations have been suggested ranging from wood burning stoves to inorganic particles, insecticides and moulds (Bresnitz and Strom 1983; Newman, Rose et al. 2004; Rybicki, Amend et al. 2004). The recent advancement in technology and the use of polymerase chain reaction to amplify the genetic products of sampled tissue resulted in the discovery of mycobacterial antigens in serum samples taken from patients with Sarcoidosis (Song, Marzilli et al. 2005). Most investigators however favour an immune response abnormality and that the antigen in question is of lesser significance. Evidence for this was seen with the association between human leukocyte antigen variants and Sarcoidosis, especially the good correlation between HLA-DQB1*0201 and acute disease with a good prognosis (Sato, Grutters et al. 2002). The majority of Sarcoidosis affected individuals do not develop progressive fibrotic disease; indeed, two thirds of patients will have a remission with half achieving this within three years. The response once achieved is also favourable with less than 5% of patients achieving remission in one year subsequently having a relapse. In essence this results in one third of