Abstract: TH-PO517
Systemic AL Amyloidosis With an Undetectable Plasma Cell Dyscrasia: A Rare Entity
Session Information
- Glomerular Diseases: Clinical, Outcomes, Trials - I
November 03, 2022 | Location: Exhibit Hall, Orange County Convention Center‚ West Building
Abstract Time: 10:00 AM - 12:00 PM
Category: Glomerular Diseases
- 1303 Glomerular Diseases: Clinical‚ Outcomes‚ and Trials
Authors
- Gaytan Arocha, Jorge, Instituto Nacional de Ciencias Medicas y Nutricion Salvador Zubiran, Ciudad de Mexico, Ciudad de México, Mexico
- Ramirez-Sandoval, Juan Carlos, Instituto Nacional de Ciencias Medicas y Nutricion Salvador Zubiran, Ciudad de Mexico, Ciudad de México, Mexico
- Correa-Rotter, Ricardo, Instituto Nacional de Ciencias Medicas y Nutricion Salvador Zubiran, Ciudad de Mexico, Ciudad de México, Mexico
- Mejia-Vilet, Juan M., Instituto Nacional de Ciencias Medicas y Nutricion Salvador Zubiran, Ciudad de Mexico, Ciudad de México, Mexico
Introduction
AL Amyloidosis is characterized by a plasma cell dyscrasia that can be detected in 99% by monoclonal protein on abnormal serum free light chain (sFLC) concentrations or immunofixation electrophoresis (IFE).
Case Description
A 47-year-old man was admitted to the emergency department and afterward to the intensive care unit due to severe COVID-19-associated pneumonia. Initial laboratory studies showed: hemoglobin 12.1 g/dL, creatinine 2 mg/dL, albumin 1.69 g/dL, AST 20 U/L, ALT 19 UI, urine analysis with no erythrocytes, urine protein/creatinine ratio 4.9 g/g, HbA1c 5.5%, C3 150 mg/dL, C4 35 mg/dL. Serological testing for hepatitis B, C, HIV, ANA, and anti-PLA2R were negative. After three months of hospitalization, the patient was discharged home and lost his outpatient follow-up. He returned five months later with a nephrotic syndrome. Laboratory studies showed: creatinine 1.47 mg/dL, urine proteins 5.7g/day, sFLC λ 90.1 mg/L (8.3-27), sFLC κ 43 mg/L (6.7-22.4), sFLC ratio 0.48 (0.31-1.56), urine and serum protein electrophoresis negative, urine and serum IFE negative. We performed a renal biopsy, consistent with amyloidosis with positivity for Congo red staining. Immunofluorescence reported light chain restriction +++ for λ (figure 1) and was negative for IgG, IgM, IgA, C1q, C3c, κ, and albumin. A bone biopsy reported no evidence of plasmatic cell neoplasia and was negative for Congo red staining. An echocardiogram showed no evidence of amyloid affection. Hematology stratified the patient as low risk, so they started protocol for autologous stem cell transplantation as definitive treatment but decided to consider CyBorD as induction therapy.
Discussion
This case illustrates a patient with systemic AL amyloidosis without evidence of plasma cell dyscrasia by conventional techniques. It could be explained because the hematologic disease is so subtle that it goes undetected. The parameter for response in his follow-up will be the improvement of proteinuria, as we cannot measure classic criteria of hematologic response.
Figure 1