Unusual Findings in a Myeloma kidney: A Light- and Electron-Microscopic Study

Abstract

A case of IgD myeloma together with the existence of myelofibrosis is presented. More interesting is the concurrent presence of cast nephropathy, light chain deposition and amyloidosis in the kidney. Peculiar light-microscopic, immunohistochemical, immunofluorescence and ultrastructural findings were also noted. The possible mechanisms and implications for such findings were discussed. This case was analyzed together with a review of local pictures of renal involvement in multiple myeloma.

Amino-terminal identity of co-existent amyloid and non-amyloid immunoglobulin κ light chain deposits. A human disease to study alterations of protein conformation

“…The co-existence of antigenically similar amyloid and non-amyloid k light chain deposits in different sites in single ( Figs.1 and 2) or different organs (Fig. 3), as seen in GAL, and reported by others [3][4][5][6][7][8][9][10][11], supports this concept. Other evidence comes from observations in Alzheimer's disease, in which the cerebral b-pleated fibrillar deposits in neuritic plaques and the non-fibrillar amyloid b (Ab) deposits observed in early diffuse plaques, are both related to the same Ab molecules [26].…”

“…The size, immunohistochemical and N-terminal amino acid sequence identity between the fibrillar deposits in the arteries and the non-fibrillar deposits in glomeruli indicate that they are antigenically and biochemically closely related molecules, but complete amino acid sequences are required to determine if they are identical. The detection of amyloid fibrils in arteries in GAL and in other cases of LCDD [3][4][5][6]9,10], as well as the bprotein fibrillogenesis in microvessels of Alzheimer's disease [29], are consistent with the idea that local factors may alter the protein conformation, leading to aggregation and fibril formation. Future studies of other similar cases to compare the complete amino acid sequences of the two types of deposits by similar methodological approaches are not only feasible, but also important to answer the key question of the protein-structure relationship between LCDD and AL, and the factors in AL and other types of amyloid that promote or inhibit fibrillogenesis or prevent fibril degradation.…”

“…In contrast, other deposits, as seen in light chain deposition disease (LCDD), do not bind the Congo red stain, and have a clustered granular ultrastructure. Rarely both fibrillar and non-fibrillar monoclonal light chain deposits occur in some patients in the same or different organs [3][4][5][6][7][8][9][10][11]. The reasons why fibrillogenesis occurs in AL and not in LCDD, or why in some individuals AL and LCDD may coexist in different sites in the same or different organs, is not known.…”

Πολλαπλούν Μυέλωμα

“…Οι εν λόγω κύλινδροι παρουσιάζουν ηωσινόφιλη αντίδραση και αποτελούνται από κρυσταλλοποιηµένες προσµίξεις λευκωµατίνης, ινωδογόνου, πρωτεϊνών, βαρείων IgG και ελαφρών κ ή λ αλύσων ανοσοσφαιρινών. Στη σύσταση των παραπάνω κυλίνδρων ενίοτε συµµετέχουν και άλατα ασβεστίου ή και ποσότητες κυτταροπλάσµατος αποδοµηµένων κυττάρων 224,233 .…”