Remission of light chain proximal tubulopathy in IgG λ-type multiple myeloma by lenalidomide and dexamethasone therapy.
CEN Case Rep
; 8(3): 159-165, 2019 08.
Article
in En
| MEDLINE
| ID: mdl-30721454
ABSTRACT
Light chain proximal tubulopathy is a rare manifestation of monoclonal gammopathy. A 73-year-old Japanese woman was noted to have urinary protein and hypertension on health examination and visited the regional clinic. She was noted to have IgG λ M protein and suspected of multiple myeloma. She was referred to us with massive proteinuria (7.5 g/g creatinine) and Bence Jones proteinuria without renal dysfunction. A renal biopsy revealed no glomerular abnormalities, but a tubular cast was observed partially in tubules without tubular atrophy or a crystalline structure. Direct Fast Scarlet staining was absent both in glomerulus and vascular wall. Immunofluorescence revealed λ light chain (LC) staining in the proximal tubules. Electron microscopy revealed nonspecific findings including increased lysosomes with irregular contours and mottled appearance. A bone marrow biopsy revealed plasma cell proliferation (35%) and multiple myeloma immunoglobulin G λ type. She showed progressive anemia and decrease of eGFR with elevated level of urinary ß-2 microglobulin. She was treated with lenalidomide + dexamethasone (Ld). With Ld therapy, she achieved hematologic and nephrologic remission reducing the free LC, λ/κ ratio, urinary protein level, and urinary ß-2 microglobulin level.
Key words
Full text:
1
Collection:
01-internacional
Database:
MEDLINE
Main subject:
Dexamethasone
/
Antineoplastic Agents, Hormonal
/
Lenalidomide
/
Immunologic Factors
/
Kidney Diseases
/
Multiple Myeloma
Limits:
Aged
/
Female
/
Humans
Language:
En
Journal:
CEN Case Rep
Year:
2019
Document type:
Article
Affiliation country:
Japan