Posted: Friday, April 7, 2023
Intratubular cytoplasmic amyloidosis remains a rare condition that may precede the development of immunoglobulin light-chain amyloidosis in various organs, according to a case report presented as a poster at the NCCN 2023 Annual Conference. However, the pathophysiology of this disease remains elusive. Therefore, efforts should focus on elucidating the exact mechanism of this disorder and its clinical involvement, explained Sarah Khan, MD, of Mount Sinai Hospital, Chicago, and colleagues.
The patient was a 61-year-old Black female who presented with complaints of diarrhea and dyspnea. An additional workup revealed an oliguric acute kidney injury with evidence of proteinuria of unknown etiology. She was also found to have leukocytosis, hyperglycemia, and an increased anion gap metabolic acidosis.
The patient was subsequently started on hemodialysis while additional extensive analyses were performed. Serum protein electrophoresis and serum immunoelectrophoresis were negative for an M spike and monoclonal proteins, respectively. However, the kappa-to-lambda light chain ratio and free kappa light chains were both elevated. These findings prompted a renal biopsy, which revealed evidence of intratubular cytoplasmic amyloidosis. Furthermore, a CT scan showed evidence of mild hepatomegaly and hepatic steatosis but was negative for evidence of bony lesions. Moreover, her echocardiogram did not show any evidence of cardiac involvement.
The patient was immediately started on combined systemic therapy with bortezomib, cyclophosphamide, daratumumab, and dexamethasone. She simultaneously received six sessions of hemodialysis, which was discontinued after her first dose of the combined systemic therapy because of an improvement in her renal function. The decision was made to treat her with hematopoietic cell transplantation. Thus far, she has achieved a good partial response to treatment.
Disclosure: Dr. Khan reported no conflicts of interest.