Comedian Bernie Mac died August 9, 2008 of pneumonia, possibly a complication of Sarcoidosis, a condition he had a number of years.  Sarcoidosis is one of those incompletely understood conditions caused by an abnormal immune response. This abnormal response produces clumps of inflammatory cells which can either heal, or cause scarring.  The organs most frequently affected are the lungs, skin, lymph nodes, joints and eyes. If the lungs are involved, symptoms may include cough, wheezing, or shortness of breath.  Skin signs include lumps, ulcers, or areas of discolored skin. There may also be nonspecific symptoms such as weight loss, night sweats and decreased appetite. Treatment for troublesome symptoms usually involves the corticosteroid, Prednisone. 

For more information

General, Diagnosis, Symptoms:
http://www.nhlbi.nih.gov/health/dci/Diseases/sarc/sar_whatis.html
http://www.nlm.nih.gov/medlineplus/sarcoidosis.html
http://www.nlm.nih.gov/medlineplus/tutorials/sacroidosis/htm/index.htm
http://www.nlm.nih.gov/medlineplus/ency/article/000076.htm
http://www.pulmonologychannel.com/sarcoidosis/symptoms.shtml

Diagnosis:
http://www.nhlbi.nih.gov/health/dci/Diseases/sarc/sar_diagnosis.html
http://www.stopsarcoidosis.org/sarcoidosis/diagnosis.htm

Treatment:
http://www.nhlbi.nih.gov/health/dci/Diseases/sarc/sar_treatments.html
http://my.clevelandclinic.org/disorders/Sarcoidosis/hic_Sarcoidosis_Treatment_Options.aspx
http://www.mayoclinic.com/health/sarcoidosis/DS00251/DSECTION=treatments-and-drugs

Support groups:
http://clinicaltrials.gov/search/open/condition="Sarcoidosis"
http://www.stopsarcoidosis.org/supportgroups/index.htm