Abstract
INTRODUCTION: Kidney involvement is a major cause of mortality in systemic amyloidosis. Glomerulus
is the most common site of deposition in renal amyloidosis, and nephrotic syndrome
is the most common presentation. Distinction between AA and AL is done using immunofluorescence
(IF) and immunohistochemistry (IHC). Renal biopsy helps in diagnosis and also predicting
the clinical course by applying scoring and grading to the biopsy findings.
MATERIALS AND METHODS: The study includes all cases of biopsy-proven renal amyloidosis from January 2008
to May 2017. Light microscopic analysis; Congo red with polarization; IF; IHC for
Amyloid A, kappa, and lambda; and bone marrow evaluation were done. Classification
of glomerular amyloid deposition and scoring and grading are done as per the guidelines
of Sen S et al.
RESULTS: There are 40 cases of biopsy-proven renal amyloidosis with 12 primary and 23 secondary
cases. Mean age at presentation was 42.5 years. Edema was the most common presenting
feature. Secondary amyloidosis cases were predominant. Tuberculosis was the most common
secondary cause. Multiple myeloma was detected in four primary cases. Grading of renal
biopsy features showed a good correlation with the class of glomerular involvement.
CONCLUSION: Clinical history, IF, and IHC are essential in amyloid typing. Grading helps provide
a subtle guide regarding the severity of disease in the background of a wide range
of morphological features and biochemical values. Typing of amyloid is also essential
for choosing the appropriate treatment.
Keywords
Grading - mmunofluorescence - immunohistochemistry - renal amyloidosis - typing of
amyloid
