Abstract: TH-PO641

Renal Heavy/Light-Chain Amyloidosis Diagnosed by Immunostaining and Liquid Chromatography-Tandem Mass Spectrometry in a Patient with Non-Ischemic Cardiomyopathy

Session Information

Category: Nephrology Education

  • 1302 Fellows and Residents Case Reports

Authors

  • Sugimoto, Mami, Kumamoto University Hospital, Kumamoto, Japan
  • Mukoyama, Masashi, Kumamoto University Graduate School of Medical Sciences, Kumamoto, Japan
  • Inoue, Hideki, Department of Nephrology, Kumamoto university graduate school of medical sciences, Kumamoto, Japan
  • Fukagawa, Mikiko, Kumamoto University Hospital, Kumamoto, Japan
  • Yamasaki, Tomoko, Kumamoto University Hospital, Kumamoto, Japan
  • Kakizoe, Yutaka, Department of Nephrology, Kumamoto university graduate school of medical sciences, Kumamoto, Japan
  • Izumi, Yuichiro, Kumamoto University, Kumamoto, Japan
  • Kuwabara, Takashige, Kumamoto University Graduate School of Medical Sciences, Kumamoto, Japan
  • Adachi, Masataka, Department of Nephrology, Kumamoto University, Kumamoto, Japan
  • Nakayama, Yushi, Department of Nephrology, Kumamoto university graduate school of medical sciences, Kumamoto, Japan
Background

Heavy- and light-chain amyloidosis (AHL) is a rare type of amyloidosis caused by deposition of monoclonal immunoglobulin heavy and light chain. Compared with patients with renal light-chain amyloidosis (AL), those with renal AHL are reported to be rarely complicated with cardiac amyloidosis, resulting in relatively better survival. We here report a rare case of renal AHL diagnosed by immunofluorescent staining and liquid chromatography-tandem mass spectrometry (LC-MS/MS) in a patient with non-ischemic cardiomyopathy.

Methods

A 73-year-old woman was referred to our hospital due to proteinuria and hematuria. Non-ischemic cardiomyopathy had been diagnosed 6 years before. Cardiac amyloidosis was suspected, but only slightly delayed gadolinium enhancement by cardiac MRI, which was confined to the inferolateral wall, did not meet the criteria for cardiac amyloidosis. She had received implantable cardioverter defibrillator because of ventricular arrhythmia. Approximately 1 year before the referral, she had experienced hematuria with no proteinuria when her serum creatinine level was 0.7 mg/dL. Upon admission, she exhibited an increased serum creatinine level to 1.89 mg/dL and significant proteinuria of 2.83 g/g creatinine. Plasma electrophoresis showed the presence of IgG-κ monoclonal protein. The ratio of κ:λ free light chain levels in serum was increased. Renal AL was first suspected on the basis of diagnosis by kidney biopsy. However, monoclonal immunoglobulin heavy-chain deposition was revealed by immunofluorescent staining and LC-MS/MS. Therefore, we finally diagnosed her as having renal AHL. We started to treat her with low doses of dexamethasone and lenalidomide, but the treatment was abandoned due to acute exacerbation of chronic heart failure. Echocardiogram exhibited concentric left ventricular hypertrophy. Further scrutiny and close follow-up are crucial to demonstrate that she suffered from cardiac amyloidosis complicated with AHL.

Conclusion

We here report a rare case of renal AHL diagnosed with LC-MS/MS, who could be probably complicated with morbid cardiac amyloidosis. Accurate diagnosis is extremely important to give insight into prognostic implication in patients with AHL.