Sickle cell disease: a case report of renal amyloidosis

Renal Amyloid-Associated (AA) Amyloidosis in a Sickle Cell Patient: A Case Report and Literature Review

Renal amyloid-associated (AA) amyloidosis is a rare occurrence in sickle cell disease (SCD). Very little literature is available on renal AA amyloidosis in sickle cell disease. Nephrotic range proteinuria is associated with higher mortality among patients with SCD. We present a case of a young reproductive-age African American woman who presented with massive nephrotic range proteinuria. Other more common causes of AA amyloidosis such as immunologic and infectious etiologies were ruled out by history, physical examination, radiologic investigation, and serology. Renal biopsy showed mesangial expansion with Congo red-positive material. Staining for immunoglobulins was negative. Electron microscopy showed nonbranching fibrils. These findings were consistent with AA amyloidosis. This case report adds to the rare findings of renal AA amyloidosis in sickle cell disease. The patient refused any intervention to decrease her Glomerular Filtration Rate (GFR) in the hopes of potentially reversing the disabling proteinuria. We report sickle cell disease presenting with nephrotic syndrome secondary to AA amyloid.

Sickle cell nephropathy: A review of novel biomarkers and their potential roles in early detection of renal involvement

Whether the underlying mutations are homozygous, heterozygous, or co-inherited with other hemoglobinopathies, sickle cell disease is known to afflict the kidneys, leading to the clinical entity known as sickle cell nephropathy (SCN). Although common, SCN remains diagnostically elusive. Conventional studies performed in the context of renal disorders often fail to detect early stage SCN. This makes the quest for early diagnosis and treatment more challenging, and it increases the burden of chronic kidney disease-related morbidity among patients. Novel diagnostic tools have been employed to overcome this limitation. In this study, we discuss various biomarkers of SCN, including those employed in clinical practice and others recently identified in experimental settings, such as markers of vascular injury, endothelial dysfunction, tubulo-glomerular damage, and oxidative stress. These include kidney injury molecule-1, monocyte chemoattractant protein-1, N-acetyl-B-D-glucosaminidase, ceruloplasmin, orosomucoid, nephrin, and cation channels, among others. Furthermore, we explore the potential of novel biomarkers for refining diagnostic and therapeutic approaches and describe some obstacles that still need to be overcome. We highlight the importance of a collaborative approach to standardize the use of promising new biomarkers. Finally, we outline the limitations of conventional markers of renal damage as extensions of the pathogenic process occurring at the level of the organ and its functional subunits, with a discussion of the expected pattern of clinical and biochemical progression among patients with SCN.