Amyloid A amyloidosis and systemic lupus erythematosus

Concurrence of leukocyte chemotactic factor 2-associated amyloidosis and autoimmune diseases: A case report

Leukocyte chemotactic factor 2-associated (ALECT2) amyloidosis is one of the recently reported types of amyloidosis, which is caused by the extracellular deposition of leukocyte chemotactic factor 2 (LECT2). There have not been any reports involving the concurrence of ALECT2 amyloidosis with Sjögren’s syndrome (SS) or systemic lupus erythematosus (SLE)s. Herein, we report a case of a 68-year-old Chinese woman presenting with long duration of sicca symptoms. The clinical evaluation and laboratory findings showed that she had SS overlapped with SLE. Kidney biopsy revealed a membranoproliferative glomerulonephritis (MPGN) with glomerular deposition of dominant IgG3-kappa by immunofluorescene, which was related to SS/SLE. Furthermore, patchy congophilic amyloid deposits in the tubulointerstitium were detected, which were positive for LECT2 protein by immunohistochemical staining and immunoelectron microscopy. This is the first case of ALECT2 amyloidosis that coexisted with SS/SLE, and the causal relationship between ALECT2 amyloidosis and autoimmune diseases remain unclear.

Multifocal head and neck amyloidosis as a diagnostic clue of systemic lupus erythematosus (SLE): A case report

RATIONALE

Amyloidosis accounts for 2% of head and neck tumors. Amyloidosis that develops in the head and neck region is localized amyloidosis. Multifocal amyloidosis in the head and neck region is extremely rare.

PATIENT CONCERNS

The patient presented to the clinic of otolaryngology with nasal obstruction, anosmia and left neck mass for several months.

DIAGNOSIS

A left nasopharynx tumor was revealed under nasopharyngeal scope. Eosinophilic, proteinaceous material was revealed under a pathology scope in the nasopharynx tissue and neck tumor. Congo red staining demonstrated pale congophilic amorphous material with apple-green birefringence under cross-polarized light, and multifocal amyloidosis was diagnosed. Amyloidosis secondary to systemic lupus erythematosus (SLE) was confirmed after a series of investigations.

INTERVENTIONS

The patient underwent local excision for multifocal amyloidosis without following management. To control underlying SLE, the patient accepted steroid pulse therapy and immunosuppressants. The patient eventually achieved disease remission.

OUTCOMES

During the 6 months of follow-up in the outpatient department of otolaryngology and rheumatology, complications, recurrence of nasopharyngeal amyloidosis, and SLE flare-up were not observed.

LESSONS

Head and neck amyloidosis involving the nasopharynx is a rare presentation of this disease. Head and neck multifocal amyloidosis should be taken as a hint of systemic disease. In head and neck amyloidosis, a comprehensive survey should be performed to clarify the underlying disease predisposing to amyloidosis and organ involvement.

Experimental transmission of systemic AA amyloidosis in autoimmune disease and type 2 diabetes mellitus model mice

AA amyloidosis is a protein misfolding disease characterized by extracellular deposition of amyloid A (AA) fibrils. AA amyloidosis has been identified in food animals, and it has been postulated that AA amyloidosis may be transmissible to different animal species. Since the precursor protein of AA fibrils is serum amyloid A (SAA), which is an inflammatory acute phase protein, AA amyloidosis is considered to be associated with inflammatory diseases such as rheumatoid arthritis. Chronic diseases such as autoimmune disease and type 2 diabetes mellitus could be potential factors for AA amyloidosis. In this study, to examine the relationship between the induction of AA amyloidosis and chromic abnormalities such as autoimmune disease or type 2 diabetes mellitus, amyloid fibrils from mice, cattle, or chickens were experimentally injected into disease model mice. Wild-type mice were used as controls. The concentrations of SAA, IL-6, and IL-10 in autoimmune disease model mice were higher than those of control mice. However, induction of AA amyloidosis in autoimmune disease and type 2 diabetes mellitus model mice was lower than that in control mice, and the amount of amyloid deposits in the spleens of both mouse models was lower than that of control mice according to Congo red staining and immunohistochemistry. These results suggest that factors other than SAA levels, such as an inflammatory or anti-inflammatory environment in the immune response, may be involved in amyloid deposition.