Clinical And Pathological Characteristics Of Light Chain Nephropathy Of Amyloidosis

Objective:To explore the clinical manifestations and renal pathological features of patients with light chain nephropathy of amyloidosis,deepen the understanding of the disease and improve the diagnosis and treatment of the disease.Method:Nine patients with light chain nephropathy of amyloidosis diagnosed by renal biopsy from the June 2015 to February 2019 in Hebei General Hospital were enrolled in the study.Gender,age,primary and accompanying symptoms were gathered,complete blood count,urinalysis,biochemical project echocardiography,abdominal ultrasound and renal histopathology were performed.Clinical characteristics,laboratory results and renal pathological features were analysed.Review the relevant papers to analyze the epidemiological status,clinical features and pathological characteristics of light chain nephropathy of amyloidosis.Results:1.Among the 9 patients,8 were males and 1 was female,the ratio of male to female was 8:1,with an average age of 58.67±7.53 years,the youngest patient was 43 years old,and most patients were between 50-70 years old;2.The patients’ primary clinical symptoms were as follows: lower extremity edema,asymptomatic proteinuria,chest tightness and shortness of breath after exercise,and intermittent shoulder and back pain.The median duration from the onset of symptoms to the time of diagnosis was 7 months,and the longest time was 24 months.At the time of diagnosis,multiple organs were involved in 2 patients,1 patient with kidney,heart and peripheral nerve involvement,and 1 patient was involved in kidney,heart and liver.3.Serum and urine immunofixation electrophoresis(IFE)assay were gathered in 9 patients.Six patients(66.67%)were positive for monoclonal free light chain in serum IFE assay,7 patients(77.78%)were positive for monoclonal free light chain in urine IFE assay,including 6 patients positive for monoclonal free λ chain and 1 patient positive for monoclonal free κ chain.2 patients were negative for monoclonal free light chain in serum and urine IFE assay.Serum free light chain(FLC)were performed in all patients,7 patients(77.78%)with λ FLC above the reference limit,1 patient(11.11%)with κ FLC above the reference limit,7 patients(77.78%)with a FLC κ/λ ratio abnormal obviously.4.Renal biopsy was performed in all patients,pathological results suggested that glomerular damage mainly,glomerular basement membrane and mesangial regions were most commonly involved,and all patients had varying degrees of glomerular sclerosis.These amyloid proteins were presented as homogeneous unstructured agglomerates in HE staining,and performed negative in PAS staining.Amyloids were positive in Congo Red staining and generally demonstrate straight and unbranching fibrils 8 to 10 nm in width under electron microscopic examination.Conclution:1.Men with light chain nephropathy of amyloidosis are more prominent than women.Most of the patients are more common in middle and old aged persons;2.The clinical manifestations of this disease are lack of specificity.Edema is the most common symptom,most patients present with nephrotic syndrome,and as the disease progresses,renal insufficiency gradually develops,the rate of missed diagnosis and misdiagnosis is high.In addition to involving the kidneys,the disease is complicated by involvement of other organs.and the more organs are involved,the worse the prognosis is;3.Serum and urine immunofixation electrophoresis and free light chain have high sensitivity for the diagnosis of this disease.For patients with middle-aged and elderly patients with nephrotic syndrome should be screened.Patients with AL-λ are prominent the AL-κ,however,patients with AL-κ tend to involve liver,and kidney involvement is more severe;4.In the kidney,amyloid deposits may be found in any of the parenchymal compartments,including glomeruli,tubules,interstitium and/or vessels,glomerular basement membrane and mesangial regions are most commonly involved;5.Patients with suspected disease should be promptly examined by renal biopsy for Congo red and immunofluorescence.Electron microscopy is indispensable to reduce the missed diagnosis.