amyloosia

Amyloidosis is a group of rare, systemic or localized disorders characterized by the abnormal deposition of insoluble amyloid fibrils in tissues and organs. These fibrils are composed of misfolded proteins that accumulate extracellularly, disrupting normal cellular function and leading to progressive organ dysfunction.

The condition derives its name from the Greek word *amylon*, meaning "starch," due to the initial observation that amyloid deposits stain similarly to starch under certain dyes. Amyloidosis can be classified into several types based on the primary protein component of the fibrils, including light-chain (AL) amyloidosis, associated with plasma cell dyscrasias; transthyretin (ATTR) amyloidosis, linked to mutations in the transthyretin gene; and senile systemic amyloidosis, which occurs sporadically in older adults. Other forms include familial Mediterranean fever-related amyloidosis (AA amyloidosis) and dialysis-related amyloidosis (Aβ2M amyloidosis).

Symptoms vary widely depending on the affected organs but often include fatigue, weight loss, swelling, and organ-specific manifestations such as heart failure, neuropathy, or renal impairment. Diagnosis typically involves a combination of clinical evaluation, imaging studies, and tissue biopsy to confirm amyloid deposition, often using techniques like Congo red staining and apple-green birefringence under polarized light microscopy.

Treatment approaches depend on the underlying cause and type of amyloidosis. For AL amyloidosis, therapies such as chemotherapy or autologous stem cell transplantation target the underlying plasma cell disorder. In ATTR amyloidosis, medications like tafamidis or gene therapy may stabilize or improve symptoms. Organ transplantation may be considered in select cases, though it is not universally curative. Supportive care, including fluid management and symptom relief, is also essential.

Prognosis varies significantly, with some forms progressing rapidly while others have a more indolent course. Early diagnosis and multidisciplinary management are critical for improving outcomes in amyloidosis. Research continues to advance understanding and therapeutic options for this complex group of disorders.