Demonstration and classification of XXXX in needle biopsies of the kidneys, with special reference to @entity2783 of the AA-type.

@entity1 @entity8 @entity5066 @entity19592 @entity527 @entity1885 @entity2783
To examine whether sequence-specific antibodies directed against serum amyloid A were useful in the demonstration and classification of @entity2783 , needle biopsy specimens from the kidneys of 152 cases with @entity8 were investigated using the avidin- @entity1885 -peroxidase complex technique of immunohistochemistry. A distinct immunoreactivity of @entity5066 was seen in biopsies from all 42 individuals who were clinically classified as having the AA-type of @entity2783 . The stained areas coincided with deposits stained by Congo red. Four of these cases demonstrated immunoreactivity of both @entity5066 and light immunoglobulin chains and all biopsies except one showed immunoreactivity for the amyloid P-component. After treatment with @entity19592 , the @entity527 in the biopsies of all 42 cases lost their affinity for Congo red. Ten @entity1 with clinical and laboratory findings compatible with the AL-type of @entity2783 were also investigated. All their biopsies demonstrated @entity527 but none of them showed any immunoreactivity of @entity5066 . @entity527 of lambda light immunoglobulin chains-but not kappa-were demonstrated in biopsies from four @entity1 . The amyloid P-component was found in biopsies from six individuals and positive Congo red staining after treatment with @entity19592 was seen in biopsies from four of the cases. Biopsies of 100 @entity1 suffering from @entity8 were also examined. None of them displayed any immunoreactive deposits of @entity5066 . The investigation shows that @entity527 of the AA-type can be identified in needle biopsies when sequence-specific antibodies against serum amyloid A are used in the avidin- @entity1885 -peroxidase complex technique. Both the diagnostic sensitivity (42 of 42) and specificity (110 of 110) of the assay were optimal (1.0). The method was found to be superior to other investigated techniques and useful for classifying @entity2783 in formalin-fixed renal biopsies.
