Amyloidosis life expectancy
Amyloidosis is a rare disorder characterized by the deposition of abnormal protein called amyloid in the body.
Amyloid is an abnormal protein built up of fibril proteins (95%), the P component and several glycoproteins. In the microscope amyloid is seen as an extracellular hyaline substance. The three common forms of amyloid are distinguished:
- AL (amyloid light chain) – consists of the light immunoglobulin chains;
- AA (amyloid-associated) produced in the liver;
- Aβ – typical for Alzheimer disease;
Amyloidosis life expectancy results in the multiple organ failure.
Amyloidosis life expectancy may be systemic when multiple organs are affected or localized when amyloid is found in solely organ. Primary amyloidosis is usually associated with the impaired immunity and secondary amyloidosis is related to other chronic inflammatory conditions. There is also a separate group of hereditary (familial) amyloidosis conditions.
See also: Renal Amyloidosis
Common symptoms of amyloidosis include:
- Fatigue and weakness;
- Edema (swelling of the feet or legs, less commonly – the face);
- Shortness of breath;
- Arrythmia (abnormal heart rhythms);
- Appetite and weight loss;
- Paresthesias (abnormal sensation in the fingers and toes);
- Bruising and bleeding easily;
- Nails damage and hair loss (alopecia);
- Difficulties swallowing;
- Macroglossia (large tongue);
Staging of AL amyloidosis
Stages of AL Amyloidosis life expectancy are defined according to cardiac biomarker level in the serum and therefore varies the survival rate.
|Stage||Definition||Median survival (months)|
|I||Both troponin and BNP (Brain Natriuretic Peptide) below threshold (<0.035mcg/L and <100ng/L, respectively)||26.4|
|II||Either troponin or BNP above|
|III||Both troponin and BNP above|
Another staging system is based on the serum levels of cardiac troponin T(≥0.025 ng/mL); N-terminal pro-brain natriuretic peptide (NT-proBNP) (≥1,800 pg/mL); and the difference between involved and uninvolved serum free light chain levels (dFLC) (>180 mg/L). Every indicator is counted as one point. The 4 stages are associated with the median survival rate of 94.1, 40.3, 14.0, and 5.8 months, respectively.
Poor prognostic factors in Amyloidosis life expectancy include:
1) Cardiac factors
- High cardiac biomarker risk according to the stages of Amyloidosis life expectancy;
- Worse NYHA classification score;
- Episodes of unconsciousness (syncope);
- Systolic blood pressure <100mmHg;
- Heart failure symptoms;
- Interventricular wall thickness >15mm;
- Ventricular arrhythmias;
2) Measures of plasma cells
- dFLC (the absolute difference between the involved and uninvolved serum free light chains) > 180mg/L;
- Marrow plasmacytosis;
3) Other factors
- More than two organs involved;
- Liver involved;
- Elevated urate;
- Autonomic neuropathy;
- Affected kidneys;
The life expectancy for untreated Al amyloidosis is poor and constitutes about 12 months. Chemotherapy prolongs the life span up to 3 years.
For those whose kidneys are affected dialysis and renal transplantation are recommended. The survival rate in case of dialysis treatment is 3years and 3 months, whereas life expectancy after renal transplantation is 7 years and 5 months.
The involvement of the heart usually indicates the 1 year survival rate.
It was estimated that the outlook is worse in AL (1- and 3-year survival rates of 68 and 63%, respectively) Amyloidosis life expectancy as opposite to ATTR Amyloidosis life expectancy (1- and 3-year survival rates of 91 and 83%, respectively).