Amyloidosis is a rare group of metabolic disorders where a protein called amyloid accumulates in body organs and tissues where it can cause damage and is potentially fatal. Symptoms depend on the organs involved. Secondary amyloidosis is caused by a chronic infection of inflammatory conditions such as rheumatoid arthritis, multiple myeloma, tuberculosis and osteomyelitis. The main organs affected in secondary amyloidosis are usually the kidneys, liver, spleen and lymph nodes. The peripheral and autonomic nerves and the heart are rarely affected. See also Amyloidosis, inflammatory