OBJECTIVETo investigate the pathologic features and diagnostic algorithm of light chain nephropathy (LCN).

METHODSSeven cases of LCN were studied by light microscopy, electron microscopy and immunolabeling of light chains (kappa, lambda) by immunofluorescence and immunoelectron microscopy.

RESULTSThe histopathology of 7 cases by light microscopy was variable, with 3 cases showing nodular glomerulosclerosis, 1 case showing mild to moderate mesangial proliferation, and 3 cases showing cast nephropathy with minimal glomerular change. Immunofluorescence study revealed positive staining of a single type of light chain in mesangium (nodular pattern) or along glomerular basement membrane (linear), along tubular basement membrane and around arteriolar walls in all the 7 cases. Ultrastructurally, electron-dense granular deposits were identified in mesangium, subendothelial aspect of glomerular basement membrane, outer aspect of tubular basement membrane and arteriolar walls. Immunogold labeling of light chains showed distinct labeling of a single type light chain in the granular electron-dense materials (5 cases being kappa-positive and 2 being lambda-positive).

CONCLUSIONSLCN typically shows nodular glomerulosclerosis. The ultrastructural change is characteristic and important for diagnosis. Immunolabeling of light chains by immunofluorescence and immunoelectron microscopy carries further diagnostic value, especially in cases with minimal light microscopic change.

Adult ; Aged ; Female ; Glomerulosclerosis, Focal Segmental ; immunology ; pathology ; Humans ; Immunoglobulin Light Chains ; immunology ; Immunoglobulin kappa-Chains ; immunology ; Immunoglobulin lambda-Chains ; immunology ; Kidney Diseases ; immunology ; pathology ; Kidney Glomerulus ; immunology ; pathology ; ultrastructure ; Male ; Microscopy, Fluorescence ; Microscopy, Immunoelectron ; Middle Aged

OBJECTIVETo study the expression of immunoglobulin light chain kappa and lambda (Igkappa and Iglambda) in gastric carcinoma cell and their co-expression.

METHODSIgkappa and Iglambda of 22 human gastric carcinoma specimens embedded in paraffin were monitored through immunohistochemical method-LSAB method.

RESULTSAmong 22 gastric carcinoma specimens, both Igkappa and Iglambda were positive in 17 (77.3%), only Igkappa was positive in 2 (9.1%), only Iglambda was positive in 1 (4.5%), both Igkappa and Iglambda negative in 2 (9.1%). The expression of Igkappa and Iglambda in human gastric carcinoma cell showed significant close correlation (chi(2) = 5.49, P < 0.05).

CONCLUSIONCo-expression of immunoglobulin light chain kappa and lambda in gastric carcinoma cell is common, which suggests that the activation mechanism of immunoglobulin gene in gastric carcinoma cell may be different from that in B-lymphocytes. Study on co-expression of immunoglobulin light chain kappa and lambda in gastric carcinoma is promising.

Gene Rearrangement, B-Lymphocyte, Light Chain ; Humans ; Immunoglobulin kappa-Chains ; biosynthesis ; genetics ; Immunoglobulin lambda-Chains ; biosynthesis ; genetics ; Immunohistochemistry ; Stomach Neoplasms ; immunology ; metabolism

We describe a case of solitary myeloma showing cystic change filled with massive crystalline structures in a 54-year-old woman. A bone X-ray showed a solitary cystic osteolytic lesion in the right iliac bone. Serum and urine protein electrophoresis showed no demonstrable M-protein, and bone-marrow aspirates did not show any myeloma cells. Histologic examination of the tumor revealed aggregation of plasma cells with massive extracellular infiltration of the rhomboid-shaped crystalline structures. In immunoperoxidase staining, both these crystalline structures and the cytoplasms of the myeloma cells demonstrated a positive reaction for lambda light chain. By electron microscope, the large extracellular crystalline structures were observed, and we found unique rhomboid or rectangular-shaped crystalline structures in the cytoplasms of the myeloma cells.
Bone Neoplasms/immunology/*ultrastructure ; Crystallization ; Extracellular Space/immunology ; Female ; Humans ; Immunoglobulin lambda-Chains/ultrastructure ; Microscopy, Electron ; Middle Aged ; Plasmacytoma/immunology/*ultrastructure

A mediastinal mass was incidentally found on chest radiography in a 46-yr-old woman who had had myasthenia gravis (MG) for 2 months. Computed tomography revealed a 4-cm in size, well-defined, and lobulating mass with nodular calcification that was located in the thymus. Microscopically, the mass consisted of diffuse amorphous eosinophilic materials. These deposits exhibited apple-green birefringence under polarized light microscopy after Congo red staining. Immunohistochemical analysis revealed that they were positive for both kappa and lambda light chains and negative for amyloid A. A diagnosis of localized primary thymic amyloidosis was finally made. After thymectomy, the symptoms of MG were controlled with reduced corticosteroid requirements. Localized thymic amyloidosis associated with MG has not been reported to date.
Amyloidosis/complications/*radiography/*surgery ; Calcinosis/*radiography/*surgery ; Female ; Humans ; Immunoglobulin kappa-Chains/immunology ; Immunoglobulin lambda-Chains/immunology ; Mediastinum/radiography/surgery ; Middle Aged ; Myasthenia Gravis/*complications ; Radiography, Thoracic ; Thymectomy ; Thymus Gland/radiography/surgery ; Tomography, X-Ray Computed

BACKGROUNDPrimary systemic light chain amyloidosis (AL) is a rare plasma cell disease, our purpose was to analyze the immunophenotypic characteristics of the plasma cells in bone marrow in AL patients, and explore whether the detection of abnormal plasma cell clones in bone marrow by flow cytometry (FCM) could be used as an important indicator of AL diagnosis.

METHODSFresh bone marrow samples were collected from 51 AL, 21 multiple myeloma (MM), and 5 Waldenström's macroglobulinemia (WM) patients. The immunophenotype of bone marrow cells were analyzed and compared by FCM using a panel of antibodies including CD45, CD38, CD138, CD117, CD56, and CD19.

RESULTSIn AL, light chain restriction could be identified in 31 cases (60.9%), in which the &lambda; light chain restriction was found in 24 cases (77.4%). In MM, κ light chain restriction was found in 13 cases (61.9%), and &lambda; light chain restriction in eight cases. CD45 on abnormal plasma cells was negative to weakly positive in both AL and MM, but was positive to strongly positive in WM. In the bone marrow plasma cells of the 51 AL, 78.4% were CD56+, 68.6% were CD117+, and 88.2% were CD19-. While in the 21 MM cases, 66.7% were CD56+, 38.1% were CD117+, and 90.4% were CD19-. The plasmacytoid lymphocytes in the five WM patients were CD19+ and CD56-, CD117-.

CONCLUSIONDetection of abnormal plasma cell clones in bone marrow by FCM is valuable for the diagnosis of AL.

Adult ; Aged ; Aged, 80 and over ; Amyloidosis ; immunology ; metabolism ; CD56 Antigen ; metabolism ; Female ; Flow Cytometry ; Humans ; Immunoglobulin Light-chain Amyloidosis ; Immunoglobulin lambda-Chains ; metabolism ; Immunophenotyping ; Leukocyte Common Antigens ; metabolism ; Male ; Middle Aged ; Multiple Myeloma ; immunology ; metabolism ; Proto-Oncogene Proteins c-kit ; metabolism ; Waldenstrom Macroglobulinemia ; immunology ; metabolism