Most common types of systemic amyloidosis
| Amyloid type . | Precursor protein . | Acquired/hereditary . | Proportion of new cases . | Organ involvement . |
|---|---|---|---|---|
| AL | Monoclonal immunoglobulin light chains | Acquired, caused by plasma cell clone | 78% | Heart (75%), kidney (proteinuria possibly evolving in renal failure, 65%), soft tissues (15%), liver (15%), peripheral and/or autonomic nervous system (10%), gastrointestinal tract (5%) |
| ATTRm | Mutated transthyretin | Hereditary | 7% | Peripheral and autonomic nervous system, heart, eye |
| ATTRwt (formerly senile systemic amyloidosis) | Wild-type transthyretin | Acquired, age-related | 6%, mainly males (10% after 2014) | Heart (∼100%), ligaments, tenosynovium |
| AA | Apolipoprotein SAA | Acquired, reactive to chronic inflammation | 6% | Kidney (proteinuria possibly evolving in renal failure, >95%), liver (15%), heart (10%), gastrointestinal tract (5%) |
| AApoAI | Mutated apolipoprotein AI | Hereditary | 3% | Liver, kidney (reduction of glomerular filtration rate), testis, heart, peripheral nervous system |
| ALECT2 | Leukocyte chemotactic factor 2 | Unknown | Up to 3% in the United States | Kidney, liver |
| Amyloid type . | Precursor protein . | Acquired/hereditary . | Proportion of new cases . | Organ involvement . |
|---|---|---|---|---|
| AL | Monoclonal immunoglobulin light chains | Acquired, caused by plasma cell clone | 78% | Heart (75%), kidney (proteinuria possibly evolving in renal failure, 65%), soft tissues (15%), liver (15%), peripheral and/or autonomic nervous system (10%), gastrointestinal tract (5%) |
| ATTRm | Mutated transthyretin | Hereditary | 7% | Peripheral and autonomic nervous system, heart, eye |
| ATTRwt (formerly senile systemic amyloidosis) | Wild-type transthyretin | Acquired, age-related | 6%, mainly males (10% after 2014) | Heart (∼100%), ligaments, tenosynovium |
| AA | Apolipoprotein SAA | Acquired, reactive to chronic inflammation | 6% | Kidney (proteinuria possibly evolving in renal failure, >95%), liver (15%), heart (10%), gastrointestinal tract (5%) |
| AApoAI | Mutated apolipoprotein AI | Hereditary | 3% | Liver, kidney (reduction of glomerular filtration rate), testis, heart, peripheral nervous system |
| ALECT2 | Leukocyte chemotactic factor 2 | Unknown | Up to 3% in the United States | Kidney, liver |
The amyloid types are identified by acronyms, where the letter “A” for amyloidosis is followed by the abbreviation of the protein forming the amyloid fibrils. The relative incidence is calculated on 2548 patients with systemic amyloidosis referred to the Pavia Amyloidosis Research and Treatment Center between 1986 and 2015, unless indicated otherwise. ALECT2 amyloidosis is a recently identified amyloidosis with a relatively high incidence in Hispanic and Native American people. No cases have been reported in Europe so far. AApoAI amyloidosis has a high prevalence in northern Italy. The proportion of patients with wild-type transthyretin amyloidosis (ATTRwt), senile, amyloidosis is steadily increasing in recent years, mainly because of the recognition that scintigraphy with bone tracers can detect cardiac ATTR.