Introduction:
Inflammatory (AA) amyloidosis is a type of amyloidosis characterized by deposition of excess insoluble serum amyloid A (SAA) proteins produced in chronic inflammatory conditions. There is paucity of data about this disease in the Indian population. The aim of the study was to delineate the clinical profile and outcome of AA amyloidosis in Indian patients.
Methods:
In a retrospective study we screened our kidney biopsy registry data from 2013 to 2021 to identify patients diagnosed with AA amyloidosis. Demographic details and laboratory data were collected from medical records. Primary outcome was deterioration of renal function defined as sustained decline in eGFR by >50% documented during at least 2 consecutive clinic visits with no recovery or progression to end stage kidney disease (ESKD).
Results:
Of the 3853 kidney biopsies done during the study period, there were 63 (1.6%) cases of AA amyloidosis. Median age at presentation was 63 (IQR 31-56) years and 47 (74.6%) were male. Hypertension was present in 10 (15.9%) cases and 3 (4.8%) were diabetic. 45 (71.4%) patients had past/present history of some chronic inflammatory disease of which 9 had history of two or more conditions. 22 (34.9%) patients had past history of tuberculosis. 13 (20.6%) patients had chronic inflammatory joint diseases, 4 (6.3%) had history of malignancy. Median eGFR was 68.1 (IQR 28.8-111.8) ml/min/1.73 m2, serum albumin was 2.2 (IQR 1.8-2.8) g/dl and proteinuria was 4.4 (IQR 3.0-7.4) g/day and 14 (22.2%) had hematuria at diagnosis.
During a median follow up of 42.5 (IQR 23 to 65) months after diagnosis, 25 (39.7%) reached the primary outcome, of which 15 had progressed to ESKD. However; age, gender, BMI, mean arterial BP (MAP), past history of TB, history of rheumatological disorder, eGFR, serum albumin at biopsy and 24 hr urine protein were not found to have significant association with the primary outcome.
Conclusions:
The prevalence of inflammatory (AA) amyloidosis is low in Indian patients. Majority had a documented predisposing chronic inflammatory disease. In the absence of definitive treatment renal survival is poor.
I have no potential conflict of interest to disclose.
I did not use generative AI and AI-assisted technologies in the writing process.