Brazilian consensus recommendations on the diagnosis and treatment of light chain amyloidosis

INTRODUCTION: Systemic immunoglobulin light chain amyloidosis is characterized by the extracellular deposition of misfolded light chains, leading to progressive dysfunction of multiple organs. Diagnosis remains a significant clinical challenge and is frequently delayed due to the presence of nonspecific symptoms, coupled with limited access to specialized diagnostic tools and expertise. Currently, no established national recommendations for the diagnosis and management of this condition exist in Brazil. METHODS: These expert recommendations were developed following a structured advisory meeting in May 2025. The guidelines were formulated after a national survey of 96 Brazilian institutions (50 private and 46 public). Key diagnostic and therapeutic challenges were identified, including delayed diagnosis, limited access to biopsy techniques and biomarker testing, and uneven availability of treatment options. Recommendations focused on areas where consensus would benefit healthcare professionals in establishing best practices. RESULTS: The recommendations included: 1) Early detection: Educational initiatives for patients and healthcare professionals and the establishment of multidisciplinary specialized centers are needed to improve time to diagnosis and subsequent prognosis. 2) Accurate diagnosis: Clear, standardized procedures for tissue biopsy and timing are necessary to ensure accurate diagnosis and efficient testing. Improved access to Congo red staining and polarized light microscopy is critical. 3) Evaluation and classification: Biomarker testing should be used at all stages. Validated biomarker cut-offs and scoring systems should be implemented to standardize patient evaluation and risk stratification. 4) Optimal management and treatment: A multidisciplinary approach is crucial. Daratumumab should be added, if available, to bortezomib, cyclophosphamide and dexamethasone. Bortezomib and melphalan based regimens are an alternative. CONCLUSION: These expert-guided recommendations aim to support earlier diagnosis, standardized evaluation, and optimized treatment of light chain amyloidosis in Brazil.