Leukocyte chemotactic factor 2 (LECT2) amyloidosis presenting as pulmonary-renal syndrome: a case report and review of the literature

Abstract

Leukocyte chemotactic factor-2 (LECT2) amyloidosis has been described as being associated with kidney disease; however, no clinical manifestations outside of the kidney have been previously reported. We describe a patient presenting with pulmonary-renal syndrome found to have deposition of amyloidogenic LECT2 (ALECT2) within both the lung and the kidney. This case is unique in regard to both the patient's clinical presentation of pulmonary-renal syndrome in the setting of amyloidosis and the biopsy finding of ALECT2 deposition within the lung. It also emphasizes the importance of tissue diagnosis in such cases, given that amyloidosis was not initially considered in the differential diagnosis.

Leukocyte Cell–Derived Chemotaxin 2–Associated Amyloidosis

“…Chronic hypertension and diabetes mellitus are frequent (Table 1) (5,12). A minority of reported patients with renal ALECT2 had carcinoma (10,12,21), which was present in 13% of patients in one study (12). A patient with kidney and lung ALECT2 amyloidosis presenting with acute renal failure and hemoptysis has been reported (21).…”

“…Interestingly, most patients with ALECT2 amyloidosis reported so far were diagnosed by kidney biopsy in patients without clinically evident extrarenal organ involvement (5,12,17) or liver biopsy in patients without clinically evident extrahepatic organ involvement (11). A patient with biopsy-proven pulmonary ALECT2 amyloidosis was also reported (21). No patient with cardiac ALECT2 amyloidosis has been confirmed histologically so far, although there was one reported patient with hepatic and cardiac amyloidosis in whom the hepatic (but not cardiac) amyloid was proven to be ALECT2 by immunohistochemistry (IHC) and amino acid sequencing (22).…”

“…A minority of reported patients with renal ALECT2 had carcinoma (10,12,21), which was present in 13% of patients in one study (12). A patient with kidney and lung ALECT2 amyloidosis presenting with acute renal failure and hemoptysis has been reported (21). This patient had positive myeloperoxidase-ANCA, and therefore, his pulmonary-renal syndrome was likely caused by small-vessel vasculitis and not amyloidosis, despite the lack of crescents in the limited renal biopsy sample (eight glomeruli only) (21).…”

Leukocyte Cell‐Derived Chemotaxin‐2: It's Role in Pathophysiology and Future in Clinical Medicine

“…However, it is now known to have several other functions in the human body and it is no longer limited to chemotaxis. There has been a rapid expansion of knowledge regarding its function with major developments in liver regeneration, immune modulation, bone growth, neuronal development, glucose metabolism and metabolic syndrome, cancer, and amyloidosis, among others. It is often found secreted in the bloodstream and expression of this protein has been identified in liver cells, neurons, various epithelial cells, parathyroid cells, and white blood cells, although it is felt to be most often secreted by the liver .…”

“…However, despite the multifunctional role of LECT2 in several different organ systems, there has yet to be a comprehensive review that summarizes all of the current knowledge and information. We will attempt to synthesize current reported literature on this increasingly important protein and explore its potential future in modern clinical medicine in relation to disease pathophysiology ( Table ) and as a biomarker ( Table ) …”