Retrospective analysis of demographic and clinical characteristics in patients with secondary amyloidosis: A single-center experience

Objective: In this study, the demographic, clinical, and etiological data of patients diagnosed with and followed for AA amyloidosis in our clinic were retrospectively analyzed. The aim of the study is to identify the primary etiological factors in these patients and to perform a comparative analysis with national and international literature. Patients and Methods: Between 2014 and 2023, 65 patients with biopsy-confirmed AA amyloidosis at Manisa Celal Bayar University were retrospectively analyzed. Basic demographic data, including age, sex, and date of diagnosis, were collected for these patients. Results: Of the patients, 64.6% were male and 35.4% were female, with a mean age of 58.1±13.8 years. Female patients were diagnosed at a significantly older age compared to males. The most common presenting symptom was leg swelling (44.6%), and the most frequent physical examination finding was pretibial edema. The mean duration from symptom onset to diagnosis was 2.2 months. The most commonly biopsied organ was the kidney, with 55.4% of patients diagnosed through renal biopsy. An underlying disease was identified in 78.5% of cases, of which 40% were rheumatologic (e.g., RA, FMF, AS) and 60% were non-rheumatologic (e.g., malignancy, tuberculosis, bronchiectasis). Organ involvement was detected in 76.9% of patients, with the kidney being the most frequently affected organ. Nephrotic syndrome and renal failure were observed in 76.9% and 70.8% of patients, respectively. The need for renal replacement therapy was noted in 38.5% of cases. Inflammatory markers such as erythrocyte sedimentation rate, CRP, fibrinogen, and RDW were significantly higher in patients with rheumatologic diseases, who also exhibited more pronounced anemia. Regarding treatment, steroids (29.2%) and colchicine (23.1%) were the most commonly used therapies, with biological agents more frequently administered in patients with rheumatologic diseases. Conversely, the rate of untreated patients was higher among those without an underlying rheumatologic condition. Conclusion: In this retrospective study, the majority of patients were male. Kidney involvement and nephrotic syndrome were identified as the most common clinical manifestations. Rheumatologic diseases were among the most frequent etiological factors of AA amyloidosis, with inflammatory markers notably elevated in this subgroup. Immunosuppressive and biological agents were commonly used in treatment. Early diagnosis and effective control of inflammation are critical for the clinical course of AA amyloidosis.