What is Primary Light Chain Amyloidosis?

Amyloid is an abnormal protein that accumulates in the body, leading to amyloidosis. It can deposit in various organs, causing related problems.

Primary light chain amyloidosis is a systemic disease characterized by monoclonal immunoglobulin light chains with a reverse β-sheet structure depositing in tissues and organs, resulting in dysfunction of the affected organs.

Which Department Should You Visit for Primary Light Chain Amyloidosis?

English name: Primary Light Chain Amyloidosis (pAL).

Other names: Primary light chain amyloidosis, light chain amyloidosis.

Departments: Nephrology, Cardiology, Neurology, Gastroenterology.

What Causes Primary Light Chain Amyloidosis?

The exact cause of the disease remains unclear.

It is primarily caused by the abnormal proliferation of monoclonal plasma cells of unknown origin, which produce monoclonal immunoglobulin light chains. These light chains are processed into amyloid fibrils with a reverse β-sheet structure.

Deposition of these amyloid fibrils in tissues and organs leads to structural and functional impairment.

Who Is More Likely to Develop Primary Light Chain Amyloidosis?

No specific high-risk group has been identified, but the incidence is slightly higher in males than in females.

What Are the Main Symptoms of Primary Light Chain Amyloidosis?

Commonly affected organs include the heart, kidneys, liver, and peripheral nerves.

Symptoms depend on the involved organs and the severity of involvement:

• Kidney involvement may cause limb edema, foamy urine, proteinuria, and, in advanced stages, kidney dysfunction.
• Heart involvement may lead to shortness of breath after exertion, limb edema, pleural effusion, and ascites.
• Liver involvement may cause mild discomfort or pain in the liver area, hepatomegaly, liver dysfunction, and, in late stages, liver failure.
• Peripheral nerve and autonomic nerve involvement may result in limb numbness, weakness, orthostatic hypotension, gastrointestinal dysfunction, and sexual dysfunction.
• Skin and soft tissue involvement may cause macroglossia, tongue movement disorders, slurred speech, skin purpura, bruising, and atrophy.
• Coagulation abnormalities: Increased bleeding tendency.

How Is Primary Light Chain Amyloidosis Diagnosed?

For suspected cases, diagnostic tests include immunofixation electrophoresis of blood and urine to detect monoclonal immunoglobulins, serum free light chain testing, and pathological biopsy of affected organs or soft tissues with immuno-electron microscopy.

How Is Primary Light Chain Amyloidosis Treated?

Current treatment focuses on targeting clonal plasma cells to reduce serum monoclonal light chain levels and achieve hematologic remission, while protecting organ function, alleviating symptoms, and preventing or treating complications.

Methods to achieve hematologic remission include autologous hematopoietic stem cell transplantation, chemotherapy drugs (e.g., bortezomib, melphalan), immunomodulatory drugs, and investigational monoclonal antibodies.

What Is the Prognosis of Primary Light Chain Amyloidosis?

Prognosis is closely related to the severity of cardiac involvement. The more severe the heart involvement, the shorter the survival time. Overall prognosis is poor.

How Can Primary Light Chain Amyloidosis Be Prevented?

The cause is unknown, and no specific preventive measures are currently available.