Tocilizumab preserves renal function in rheumatoid arthritis with AA amyloidosis and end-stage kidney disease: Two case reports.

Case 1: A 59-year-old Japanese woman with rheumatoid arthritis (RA) for 36 years was admitted for evaluation of deteriorating renal function. Her serum creatine was 4.2 mg/dL, and proteinuria was 6.5 g daily. Renal and duodenal biopsy revealed AA amyloidosis. After treatment with tocilizumab (a humanized anti-interleukin-6 receptor antibody), proteinuria decreased to 1.1 g daily. The patient's renal function subsequently remained stable for 8 years. Case 2: A 71-year-old Japanese man with RA for 30 years was admitted due to deterioration of renal function. Serum creatine was 2.9 mg/dL, and urinary protein excretion was 0.06 g daily. Renal and duodenal biopsy identified AA amyloidosis. Tocilizumab was initiated, and his renal function remained stable for 6 years. The 2nd duodenal biopsy showed a marked decrease of AA amyloid deposits. Conclusion: These two cases suggest that tocilizumab may preserve renal function in the setting of end-stage kidney disease and shift the point of no return for RA patients with AA amyloidosis and renal dysfunction.

Pre-existing chronic interstitial pneumonia is a poor prognostic factor of Goodpasture's syndrome: a case report and review of the literature.

BACKGROUND: Goodpasture's syndrome is a rare disease that is characterized by rapidly progressive glomerulonephritis and diffuse alveolar hemorrhage. CASE PRESENTATION: A 71-year-old Japanese man who had chronic interstitial pneumonia was diagnosed as having Goodpasture's syndrome. Both anti-glomerular basement membrane antibody and myeloperoxidase anti-neutrophil cytoplasmic antibody were increased. Despite intensive treatments, including mechanical ventilation, he died from respiratory failure. Pathological findings at autopsy showed rapidly progressive glomerulonephritis in his kidneys, diffuse alveolar hemorrhage, hyaline membranes, and fibroblastic foci in his lungs. The cause of death was diagnosed as respiratory failure as a result of diffuse alveolar damage induced by a combination of diffuse alveolar hemorrhage and exacerbation of interstitial pneumonia. CONCLUSIONS: We report a case of Goodpasture's syndrome complicated with pre-existing chronic interstitial pneumonia and positive myeloperoxidase anti-neutrophil cytoplasmic antibody. We reviewed six similar cases reported in the literature and concluded that Goodpasture's syndrome with pre-existing interstitial pneumonia and myeloperoxidase anti-neutrophil cytoplasmic antibody is related to a poor prognosis.