Clinicopathology, diagnosis and classification of renal amyloidosis / 中华肾脏病杂志

ABSTRACT

ObjectiveTo clarify the clinicopathological features of renal amyloidosis in order to achieve early diagnosis and treatment.MethodsClinicopathological data of 26 biopsyproven renal amyloidosis cases in Department of Nephrology,Zhongshan Hospital,Fudan University between2006and2010wereanalyzedretrospectively.Immunohistochemistryand immunofluorescence of amyloid A protein,immunoglobulin light chains such as K、λ were performed on renal specimens for further classification.ResultsAge of 26 patients ranged from 40 to 77 years old,average(58.54±10.07) years.Twenty-two out of 26 patients(84.62％) were treated in local hospital before admitted to our department,and 21 patients(95.45％) were misdiagnosed as chronic primary glomerulonephritis.The prominent clinical manifestations of renal amyloidosis were nephrotic syndrome(17 cases,65.38％),decreased blood pressure(16 cases,61.53％),organ enlargement (8 cases,30.77％) and bodyweight loss (6 cases,23.08％).Fourteen out of 25 patients (56.00％) were found to have monoclonal light chains in serum by immunofixation electrophoresis.Three patients with mild pathological changes who had no confirmable Congo red stain were conffimed by electron microscopy. Twenty-three(88.46％) patients werediagnosed as AL amyloidosis,one(3.85％) as AA amyloidosis,one was strongly suspected of hereditary amyloidosis,and one was undetermined.ConclusionsRenal amyloidosis is frequently misdiagnosed.Middleaged and old nephrotic patients with decreased blood presure,organ enlargement and bodyweight loss may be the most helpful clues of the disease.Most patients have monoclonal light chains in serum or urine.Renal biopsy,especially electronic microscopy plays a crucial role in the early diagnosis of renal amyloidosis.Immunohistochemistry is important for patients with renal amyloidosis in pathological classification and treatment.