Leukocyte Cell-Derived Chemotaxin-2 Amyloidosis (ALECT2) in a Patient With Lung Adenocarcinoma: An Autopsy Report and Literature Review

Global research trends and hotspots for leukocyte cell-derived chemotaxin-2 from the past to 2023: a combined bibliometric review

Leukocyte cell-derived chemotaxin-2 (LECT2) is an important cytokine synthesized by liver. Significant research interest is stimulated by its crucial involvement in inflammatory response, immune regulation, disease occurrence and development. However, bibliometric study on LECT2 is lacking. In order to comprehend the function and operation of LECT2 in human illnesses, we examined pertinent studies on LECT2 investigation in the Web of Science database, followed by utilizing CiteSpace, VOSview, and Scimago Graphica for assessing the yearly quantity of papers, countries/regions involved, establishments, authors, publications, citations, and key terms. Then we summarized the current research hotspots in this field. Our study found that the literature related to LECT2 has a fluctuating upward trend. "Angiogenesis", "ALECT2", "diagnosis", and "biliary atresia" are the current investigative frontiers. Our findings indicated that liver diseases (e.g. liver fibrosis and hepatic cell carcinoma), systemic inflammatory disease, and amyloidosis are the current research focus of LECT2. The current LECT2 research outcomes are not exceptional. We hope to promote the scientific research of LECT2 and exploit its potential for clinical diagnosis and treatment of related diseases through a comprehensive bibliometric review.

Leukocyte Chemotactic Factor 2 Amyloidosis (ALECT2) Distribution in a Mexican Population

OBJECTIVES

To assess the prevalence of leukocyte cell-derived chemotactic 2 (LECT2), its organ involvement, and its clinical association in autopsies from an ethnically biased population.

METHODS

The tissues from all autopsies of individuals diagnosed with amyloidosis were reassessed and typed for amyloid light chain (AL) amyloidosis, amyloid A (AA) amyloidosis, transthyretin amyloidosis (ATTR), and leukocyte chemotactic factor 2 amyloidosis (ALECT2) by immunohistochemistry. Organ involvement was described and correlated with its clinical associations.

RESULTS

Of 782 autopsies, 27 (3.5%) had a confirmed diagnosis of amyloidosis. Of these, 14 (52%) corresponded to ALECT2, 5 (19%) to AL amyloidosis, 2 (7%) to ATTR amyloidosis, 1 (4%) to AA amyloidosis, and 5 (21%) as undetermined-type amyloidosis. The LECT2 amyloid deposits were found in the kidneys, liver, spleen, and adrenal glands in most individuals. Except for the kidneys, there were no clinical signs suggestive of amyloid deposition in most of the affected organs. LECT2 amyloidosis was not associated with the cause of death in any case. No cases had heart or brain involvement. Potential subclinical effects of amyloid deposition in organs such as adrenal glands and spleen require further study.

CONCLUSIONS

This autopsy study confirms the high prevalence of LECT2 amyloidosis in the Mexican population, with frequent amyloid deposition in the kidneys, liver, spleen, and adrenal glands.

Renal amyloidogenic leukocyte chemotactic factor 2 combined with IgA nephropathy: A case report

RATIONALE

Amyloidogenic leukocyte chemotactic factor 2 (ALECT2) was recently considered as a new clinicopathologic type of amyloid, which frequently affects kidney in adults and results in different degrees of renal insufficiency and failure with or without proteinuria. Here, we present a case of combining LECT2-associated renal amyloidosis with immunoglobulin (Ig)A nephropathy.

PATIENT CONCERNS

A 71-year-old Chinese man presented with edema of both lower extremities.

DIAGNOSES

There was pale eosinophilic material strongly positive for the Congo red stain in interstitium with demonstrated apple green birefringence under polarized light. Immunofluorescent stain was positive for IgA deposits (4+), IgG deposits (2+), C3 deposits (3+) within the mesangium and capillary wall. Immunohistochemistry was positive for κ (+), λ (2+) in mesangial area, and LECT2 (2+) in the interstitium. On electron microscopy, there were electron-dense deposits within mesangial area and subendothelial and randomly orientated and nonbranching fibrils 10 nm in size found in the interstitium areas. Liquid chromatography tandem mass spectrometry was performed on peptides extracted from Congo red-positive, microdissected areas of the paraffin-embedded kidney specimen. LECT 2-associated renal amyloidosis with IgA nephropathy was pathologically confirmed by renal biopsy.

INTERVENTIONS

Steroids (60 mg/d) were used to treat IgA nephropathy daily. Antihypertensive treatment was switched to an angiotensin-converting enzyme inhibitor.

OUTCOMES

One year after diagnosis, creatine remained stable in the normal range, and 24-hour proteinuria decreased to 2.9 g.

LESSONS

To date, ALECT2 has still not been comprehensively investigated. The findings of this research provide insights for concurrent IgA nephropathy with ALECT2.

Stress Response Is the Main Trigger of Sporadic Amyloidoses

Amyloidoses are a group of diseases associated with the formation of pathological protein fibrils with cross-β structures. Approximately 5-10% of the cases of these diseases are determined by amyloidogenic mutations, as well as by transmission of infectious amyloids (prions) between organisms. The most common group of so-called sporadic amyloidoses is associated with abnormal aggregation of wild-type proteins. Some sporadic amyloidoses are known to be induced only against the background of certain pathologies, but in some cases the cause of amyloidosis is unclear. It is assumed that these diseases often occur by accident. Here we present facts and hypotheses about the association of sporadic amyloidoses with vascular pathologies, trauma, oxidative stress, cancer, metabolic diseases, chronic infections and COVID-19. Generalization of current data shows that all sporadic amyloidoses can be regarded as a secondary event occurring against the background of diseases provoking a cellular stress response. Various factors causing the stress response provoke protein overproduction, a local increase in the concentration or modifications, which contributes to amyloidogenesis. Progress in the treatment of vascular, metabolic and infectious diseases, as well as cancers, should lead to a significant reduction in the risk of sporadic amyloidoses.

A case of renal and splenic LECT 2 amyloidosis: A recently recognized cause of renal and systemic amyloidosis

Amyloidosis has traditionally been of a few defined varieties, most commonly including light-chain amyloidosis (AL amyloidosis) and secondary amyloidosis due to chronic inflammation (AA amyloidosis). Apolipoprotein A-I/A-II cystatin C, gelsolin, lysozyme, fibrinogen alpha chain, beta 2 microglobulin, and transthyretin familial amyloidosis represent rarer but reported varieties. Ten years ago, the first reports linked leukocyte chemotactic factor 2 (LECT2) amyloidosis as a pathological agent identified as a novel class of amyloid-generating protein. Epidemiology suggested that this was a new cause of amyloidosis that is especially common in Hispanic patients and somewhat common among patients from the Middle East-North Africa (MENA) region. We report a case of splenic and renal LECT 2 amyloidosis in a 62-year- old Hispanic male with diabetes mellitus. After an unremarkable serological workup, LECT 2 amyloidosis was diagnosed on renal biopsy. The case presentation is reviewed as a typical presentation, and the literature is reviewed regarding this newly reported entity, resulting in infiltrative renal amyloidosis and chronic renal disease.

Renal amyloidosis: an update on diagnosis and pathogenesis

Amyloidosis is a diverse group of protein conformational disorder which is caused by accumulation and deposition of insoluble protein fibrils in vital tissues or organs, instigating organ dysfunction. Renal amyloidosis is characterized by the acellular Congo red-positive pathologic deposition of amyloid fibrils within glomeruli and/or the interstitium. It is generally composed of serum amyloid A-related protein or an immunoglobulin light chain; other rare forms lysozyme, gelsolin, fibrinogen alpha chain, transthyretin, apolipoproteins AI/AII/AIV/CII/CIII; and the recently identified form ALECT2. This disease typically manifests with heavy proteinuria, nephrotic syndrome, and finally progression to end-stage renal failure. Early diagnosis of renal amyloidosis is arduous as its symptoms appear in later stages with prominent amyloid deposition. The identification of the correct type of amyloidosis is quite troublesome as it can be confused with another related form. Therefore, the exact typing of amyloid is essential for prognosis, treatment, and correct management of renal amyloidosis. The emanation of new techniques of proteomic analysis, for instance, mass spectroscopy/laser microdissection, has provided greater accuracy in amyloid typing. This in-depth review emphasizes on the clinical features, renal pathological findings, and diagnosis of the AL and non-AL forms of renal amyloidosis.