Secondary, AA, Amyloidosis

Renal alterations in cats (Felis catus) housed in shelters and affected by systemic AA-amyloidosis: Clinicopathological data, histopathology, and ultrastructural features

AA-amyloidosis is frequent in shelter cats, and chronic kidney disease is the foremost cause of death. The aims were to describe kidney laboratory and microscopic findings in shelter cats with AA-amyloidosis. Cats were included if kidney specimens were collected post-mortem and laboratory data were available within 6 months before death. Renal lesions were evaluated with optical and electron microscopy. Mass spectrometry was used to characterize amyloid. Nine domestic short-hair cats were included; 4 females and 5 males with a median age of 8 years (range = 2-13). All cats had blood analyses and urinalyses available. Serum creatinine concentrations were increased in 6 cats and symmetric dimethylarginine was increased in all of the cats. All of the cats had proteinuria. Eight of 9 cats had amyloid in the medulla, and 9 had amyloid in the cortex (glomeruli). All cats had amyloid in the interstitium. Six cats had concurrent interstitial nephritis and 1 had membranoproliferative glomerulonephritis. All cats had extrarenal amyloid deposits. Amyloid was AA in each case. In conclusion, renal deposition of amyloid occurs in both cortex and medulla in shelter cats and is associated with azotemia and proteinuria. Renal involvement of systemic AA-amyloidosis should be considered in shelter cats with chronic kidney disease. The cat represents a natural model of renal AA-amyloidosis.

Scleroderma and scleroderma-like syndromes

Systemic sclerosis is a systemic connective tissue disease whose main pathophysiological mechanism is a progressive fibrosis of internal organs and skin leading to thickening and induration. Blood vessels may also be involved. However, systemic scleroderma is not the only disease causing cutaneous sclerosis. There is a group of diseases that mimic scleroderma in their clinical presentation - these are scleroderma-like syndromes. A distinction can be made between syndromes of inflammatory/autoimmune, genetic, metabolic, toxic, drug-induced, occupational, paraneoplastic and syndromes caused by deposition disorders. In the following paper, we have reviewed the literature on scleroderma-like syndromes. We have outlined the factors predisposing to the development of each disease, its pathogenesis, clinical presentation, diagnostic and treatment process and the differences between each syndrome and systemic scleroderma.

Development and Validation of Staging Systems for AA Amyloidosis

Key Points

Patients with AA amyloidosis and age ≥65 years, eGFR <45 ml/min per 1.73 m2, and N -terminal type-B natriuretic peptide >1000 ng/L and/or type-B natriuretic peptide >130 ng/L at diagnosis have poorer survival. Proteinuria >3.0 g/24 hours and eGFR <35 ml/min per 1.73 m2 identify patients at high risk of progression to end-stage kidney failure. Prognostic stratification in AA amyloidosis can be easily made by staging systems, similarly to AL and transthyretin amyloidosis.

Background

The kidney is involved in almost 100% of cases of AA amyloidosis, a rare disease caused by persistent inflammation with long overall survival but frequent progression to kidney failure. Identification of patients with advanced disease at diagnosis is difficult, given the absence of validated staging systems.

Methods

Patients with newly diagnosed AA amyloidosis from the Pavia (n =233, testing cohort) and Heidelberg (n =243, validation cohort) centers were included in this study. Cutoffs of continuous variables were determined by receiver operating characteristic analysis predicting death or dialysis at 24 months. Prognostic factors included in staging systems were identified by multivariable models in the testing cohort.

Results

Age ≥65 years, eGFR <45 ml/min per 1.73 m2, and elevated natriuretic peptides (type-B natriuretic peptide >130 ng/L and/or N -terminal type-B natriuretic peptide >1000 ng/L) were associated with overall survival and included in the staging system (all with simplified coefficients 1). Mean 36-month overall survival was lower with higher staging system scores (score 0–1: 92%; score 2: 72%; score 3: 32%). These results were confirmed in the validation cohort. For kidney failure, variables selected to enter in the staging system model were proteinuria >3 g/24 hour and eGFR <35 ml/min per 1.73 m2 (both with simplified coefficients 1). The 36-month cumulative incidence of kidney failure was higher with higher staging system scores (score 0: 0%; score 1: 24%; score 2: 51%). Again, similar results were obtained in validation cohort.

Conclusions

We identified and validated biomarker-based staging systems for overall survival and kidney failure in AA amyloidosis.

Systemic Amyloid A Protein Amyloidosis With Gastrointestinal Involvement

Systemic amyloidosis is a multiorgan deposition of misfolded amyloid protein fibrils. The systemic amyloid A protein (AA) amyloidosis type predominantly involves the kidney and is mostly an under-recognized complication among persons who inject drugs. Gastrointestinal involvement in systemic AA amyloidosis that is associated with illicit drug use is uncommon. In this report, we present a case of a 40-year-old man with history of injection drug use, recurrent skin and soft-tissue infection, and renal AA amyloidosis that presented with painless bloody bowel movement, which initially resolved with conservative management. Upon further evaluation, the patient was found to have empyema that required antibiotic therapy and bilateral pleural drain. His hospital course was further complicated by multiple episodes of hematochezia requiring gastrointestinal consultation. Subsequent gastrointestinal biopsy revealed amyloid deposit.

Cardiac amyloid deposition and the forensic autopsy - A review and analysis

Although amyloid material in the heart is not infrequently encountered at autopsy it may on occasion be difficult to determine the significance in terms of possible contributions to the terminal mechanisms of death. A review was undertaken of the literature and of autopsy cases at Forensic Science SA over a 20-year-period (2003-2022) for all cases where significant amyloid material had been encountered on microscopy of the heart. Sixteen cases were found consisting of 11 cases where cardiac amyloid was involved in the lethal episode, and five where it was considered an incidental feature. Of the 11 lethal cases, there were three where cardiac amyloidosis was the cause of death, and eight where it was a contributing factor, along with ischaemic heart disease (N = 7) and bronchopneumonia (N = 1). The age range was 47-92 years, average 78.6 years, with a male to female ratio of 10:1. The weights of the hearts ranged from 496 to 1059 g - average 648 g. Of the five cases where it was considered an incidental finding, the causes of death were blunt head trauma (N = 2), small intestinal ischaemia (N = 2) and small intestinal obstruction (N = 1). The weights of the hearts ranged from 299 to 487 g, average 369 g. The most relevant types of amyloidosis in forensic cases tend to be light chain amyloidosis, senile cardiac amyloidosis and familial amyloid cardiomyopathy. Other forms of amyloidosis that affect the heart, which include reactive amyloidosis, haemodialysis-related amyloidosis and isolated atrial amyloidosis, either have minimal or no clinical significance, or are of uncertain significance. While it may be difficult to determine the prognostic significance of amyloid material at autopsy clinicopathological correlation may provide useful supportive information.

An Unusual Diagnosis in a Single-Lung Transplant Recipient: Secondary Amyloidosis

Silicosis, a progressive, fibrotic occupational lung disease with no known treatment, is an uncommon indication for lung transplant. There is a paucity of research on patients with silicosis who have received lung transplants. The long-term consequences of the native lung in patients with severe chronic silicosis who have had a single-lung transplant are also of interest. We present a case of amyloidosis in a patient who underwent a single-lung transplant for silicosis.

A comparative urinary proteomic and metabolomic analysis between renal aa amyloidosis and membranous nephropathy with clinicopathologic correlations

Urinary omics has become a powerful tool for elucidating pathophysiology of glomerular diseases. However, no urinary omics analysis has been performed yet on renal AA amyloidosis. Here, we performed a comparative urine proteomic and metabolomic analysis between recently diagnosed renal AA amyloidosis (AA) and membranous nephropathy (MN) patients. Urine samples of 22 (8 AA, 8 MN and 6 healthy control) patients were analyzed with nLC-MS/MS and GC/MS for proteomic and metabolomic studies, respectively. Pathological specimens were scored for glomerulosclerosis and tubulointerstitial fibrosis grades. Functional enrichment analysis between AA and control groups showed enrichment in cell adhesion related sub-domains. Uromodulin (UMOD) was lower, whereas ribonuclease 1 (RNase1) and α-1-microglobulin/bikunin precursor (AMBP) were higher in AA compared to MN group. Correlations were demonstrated between UMOD-proteinuria (r = -0.48, p = 0.03) and AMBP-eGFR (r = -0.69, p = 0.003) variables. Metabolomic analysis showed myo-inositol and urate were higher in AA compared to MN group. A positive correlation was detected between RNase1 and urate independent of eGFR values (r = 0.63, p = 0.01). Enrichment in cell adhesion related domains suggested a possible increased urinary shear stress due to amyloid fibrils. UMOD, AMBP and myo-inositol were related with tubulointerstitial damage, whereas RNase1 and urate were believed to be related with systemic inflammation in AA amyloidosis. SIGNIFICANCE: Urinary omics studies have become a standard tool for biomarker studies. However, no urinary omics analysis has been performed yet on renal AA amyloidosis. Here, we performed a comparative urinary omics analysis between recently diagnosed renal AA amyloidosis (AA), membranous nephropathy (MN) patients and healthy controls. Pathological specimens were scored with glomerulosclerosis (G) and tubulointerstitial fibrosis (IF) grades to consolidate the results of the omics studies and correlation analyzes. Functional enrichment analysis showed enrichment in cell adhesion related sub-domains due to downregulation of cadherins; which could be related with increased urinary shear stress due to amyloid deposition and disruption of tissue micro-architecture. In comparative proteomic analyzes UMOD was lower, whereas RNase1 and AMBP were higher in AA compared to MN group. Whereas in metabolomic analyzes; myo-inositol, urate and maltose were higher in AA compared to MN group. Correlations were demonstrated between UMOD-proteinuria (r = -0.48, p = 0.03), AMBP-eGFR (r = -0.69, p = 0.003) and between RNase1-Urate independent of eGFR values (r = 0.63, p = 0.01). This study is the first comprehensive urinary omics analysis focusing on renal AA Amyloidosis to the best of our knowledge. Based on physiologic roles and clinicopathologic correlations of the molecules; UMOD, AMBP and myo-inositol were related with tubulointerstitial damage, whereas RNase1 and urate were believed to be increased with systemic inflammation and endothelial damage in AA amyloidosis.

Characteristics and course of patients with AA amyloidosis: single centre experience with 174 patients from Turkey

OBJECTIVES

This study aimed to evaluate the clinical, laboratory and genetic characteristics and outcomes of patients with AA amyloidosis.

METHODS

Patients followed up in a tertiary referral centre in Turkey with the diagnosis of inflammatory rheumatic diseases and immunohistologically proven AA amyloidosis were included in the study and retrospectively analysed.

RESULTS

Among 184 patients with the diagnosis of AA amyloidosis, 174 (83 female, 91 male) were included in the analysis. The most common cause of AA amyloidosis was FMF (78.7%), and 91% of FMF-AA amyloidosis patients were carrying the p.M694V variant (74.1% homozygous). AA amyloidosis was identified earlier in patients with homozygous or compound heterozygous MEFV exon 10 variants compared with the heterozygous patients (27, 30 and 41 years, respectively). Patients with an estimated glomerular filtration rate <60 ml/min at admission had a higher frequency of progression to end-stage renal disease (P < 0.001). The overall mortality rate was 15.3% and it increased gradually in association with the amyloid burden (10% in patients with renal, 15% in renal + gastrointestinal and 43% in those with additional cardiac involvement). Renal findings responded completely to treatment in 31% of the patients, a partial response was observed in 4%, a stable course in 23.6% and progression in 38.5%. Amyloid storm was identified in nine patients and was found to be associated with increased mortality within 1 year.

CONCLUSION

FMF patients still constitute the majority of AA amyloidosis patients in Turkey. The MEFV genotype and associated inflammatory load may affect the age of onset of AA amyloidosis, and earlier diagnosis and stricter follow-up and treatment may delay progression of the disease.

Cardiac Amyloidosis: A Contemporary Review of Medical and Surgical Therapy

Amyloidosis is a systemic disease initiated by deposition of misfolded proteins in the extracellular space, due to which multiple organs may be affected concomitantly. Cardiac amyloidosis, however, remains a major cause of morbidity and mortality in this population due to infiltrative /restrictive cardiomyopathy. This review attempts to focus on contemporary medical and surgical therapies for the different types of cardiac amyloidosis. Amyloidosis affecting the heart are predominantly of the transthyretin type (acquired in the older or genetic in the younger patients), and the monoclonal immunoglobulin light chain (AL) type which is solely acquired. A rare form of secondary amyloidosis AA type can also affect the heart due to excessive production and accumulation of the acute-phase protein called Serum Amyloid A" (SAA) in the setting of chronic inflammation, cancers or autoinflammatory disease. More commonly AA amyloidosis is seen in the liver and kidney. Other rare types are Apo A1 and Isolated Atrial Amyloidosis (AANF). Medical therapies have made important strides in the clinical management of the two common types of cardiac amyloidosis. Surgical therapies such as mechanical circulatory support and cardiac transplantation should be considered in appropriate patients. Future research using AI driven algorithms for early diagnosis and treatment as well as development of newer genetic engineering technologies will drive improvements in diagnosis, treatment and patient outcomes.

Renal amyloid-A amyloidosis in cats: Characterization of proteinuria and biomarker discovery, and associations with kidney histology

BACKGROUND

Amyloid A (AA) amyloidosis is a protein misfolding disease arising from serum amyloid A (SAA). Systemic AA amyloidosis recently was shown to have a high prevalence in shelter cats in Italy and was associated with azotemia and proteinuria.

OBJECTIVES

Investigate urine protein profiles and diagnostic biomarkers in cats with renal AA amyloidosis.

ANIMALS

Twenty-nine shelter cats.

METHODS

Case-control study. Cats with renal proteinuria that died or were euthanized between 2018 and 2021 with available necropsy kidney, liver and spleen samples, and with surplus urine collected within 30 days before death, were included. Histology was used to characterize renal damage and amyloid amount and distribution; immunohistochemistry was used to confirm AA amyloidosis. Urine protein-to-creatinine (UPC) and urine amyloid A-to-creatinine (UAAC) ratios were calculated, and sodium dodecyl sulfate-agarose gel electrophoresis (SDS-AGE) and liquid chromatography-mass spectrometry (LC-MS) of proteins were performed.

RESULTS

Twenty-nine cats were included. Nineteen had AA amyloidosis with renal involvement. Cats with AA amyloidosis had a higher UPC (median, 3.9; range, 0.6-12.7 vs 1.5; 0.6-3.1; P = .03) and UAAC ratios (median, 7.18 × 10-3 ; range, 23 × 10-3 -21.29 × 10-3 vs 1.26 × 10-3 ; 0.21 × 10-3 -6.33 × 10-3 ; P = .04) than unaffected cats. The SDS-AGE identified mixed-type proteinuria in 89.4% of cats with AA amyloidosis and in 55.6% without AA amyloidosis (P = .57). The LC-MS identified 63 potential biomarkers associated with AA amyloidosis (P < .05). Among these, urine apolipoprotein C-III was higher in cats with AA amyloidosis (median, 1.38 × 107 ; range, 1.85 × 105 -5.29 × 107 vs 1.76 × 106 ; 0.0 × 100 -1.38 × 107 ; P = .01). In the kidney, AA-amyloidosis was associated with glomerulosclerosis (P = .02) and interstitial fibrosis (P = .05).

CONCLUSIONS AND CLINICAL IMPORTANCE

Renal AA amyloidosis is associated with kidney lesions, increased proteinuria and increased urine excretion of SAA in shelter cats. Additional studies are needed to characterize the role of lipid transport proteins in the urine of affected cats.

A rare cause of AA amyloidosis: Glomus tumor and treatment with anakinra-Case report and literature review

Systemic AA amyloidosis is associated with poorly controlled chronic inflammatory disorders. Chronic infections and inflammatory arthritis are the most common causes; however, they can also rarely occur as a complication of neoplastic disorders. The development of AA amyloidosis secondary to paraganglioma, which is a rare type of tumor, has rarely been reported in the literature. In this case, an 85-year-old female patient with a glomus tumor in the neck, who has been followed up over 50 years, applied with complaints of loss of appetite, nausea, and diarrhea for 5-6 months. While evaluating the patient, who had high levels of acute phase reactants, amyloidosis was diagnosed by salivary gland biopsy. No other cause was found to explain amyloidosis. The patient, who could not tolerate treatment with colchicine and azathioprine, is successfully treated with the interleukin-1 inhibitor anakinra. A rare relationship, systemic AA amyloidosis, which is thought to have developed as a result of long-standing jugular paraganglioma, is presented in this article. In addition, publications showing an association between paragangliomas and amyloidosis were reviewed.

Ankylosing spondylitis status and risk of secondary systemic amyloidosis: A two-sample mendelian randomization study

OBJECTIVES

There is still controversy regarding the causal relationship between ankylosing spondylitis (AS) and secondary systemic amyloidosis (SSA). This study utilized aggregated data from genome-wide association studies (GWAS) on population cohorts to investigate whether a causal relationship exists between AS and SSA.

METHODS

The genetic causal relationship between AS status and SSA was analyzed utilizing a two-sample Mendelian randomization (TSMR). The analyses were conducted using the weighted mode method (WM2), inverse variance weighted method (IVW), simple mode (SM), weighted median method (WM1), and Mendelian randomization Egger regression (MR-Egger). Among these methods, the primary results were based on the IVW approach. The association was evaluated using the odds ratio (OR) along with a 95% confidence interval (95% CI).

RESULTS

The IVW analysis revealed a positive causal relationship between AS status and SSA (OR = 1.411, 95 % CI = 1.069, 1.862, P = 0.015). Meanwhile, the WM1 (OR = 1.394, 95 % CI = 1.115, 1.742, P = 0.004) and WM2 (OR = 1.393, 95 % CI = 1.112, 1.743, P = 0.045) methods also identified a positive causal relationship between AS status and SSA. The MR-Egger method did not identify a causal relationship between AS and SSA (OR = 1.175, 95 % CI = 0.888, 1.555, P = 0.342). The SM results demonstrated that the observed genotypes did not exhibit statistically significant differences between AS and SSA (OR = 1.184, 95 % CI = 0.416, 3.366, P = 0.767). The results of the MR-Egger regression suggested that the results were unaffected by bias caused by genetic pleiotropy (Intercept = 0.283, SE = 0.134, P = 0.126). Cochran's Q test did not reveal any significant heterogeneity (Q = 1.759, P = 0.624). The "leave-one-out" analysis further confirmed that the absence of any single SNP did not impact the robustness of our results.

CONCLUSION

This study revealed a positive causal relationship between AS status and the occurrence of SSA, providing new insights into the genetic analysis of SSA.

A rare case of hydatid cyst-associated AA amyloidosis and literature review of hydatid cyst-associated nephropathy

Hydatid disease is an infective picture caused by echinococcus, which progresses with cysts in various organs, especially in the liver. Renal involvement is an unusual location in the course of the disease. Although mostly asymptomatic renal cysts are seen, rarely glomerular or tubular associated nephropathy develops. In addition, the development of amyloidosis has been shown previously in patients with untreated chronic hydatid cysts. We wanted to bring a 27-year-old female patient with a 10-year history of hydatid cyst and AA amyloidosis to the literature. In addition, in our literature review for hydatid disease-associated nephropathies, we brought together data from 12 studies involving a total of 21 cases. Of these cases, 3 were membranous glomerulonephritis (MGN), 5 were, membranoproliferative glomerulonephritis (MPGN), 1 was minimally change disease (MCD), 5 were AA amyloidosis (including our case), 3 were immunoglobulin A nephropathy (IgAN), 1 was tubulointerstitial nephritis (TIN), 1 was chronic kidney disease (CKD), 1 was TIN with mesangioproliferative glomerulonephritis (MesPGN), 1 was TIN with IgAN, 1 was MPGN with immunoglobulin M nephropathy (IgMN). In this way, we wanted to shed light on the relationship between Echinococcus and nephropathy. In this way, we wanted to emphasise the necessity of doing renal examinations in the follow-up of hydatid cyst patients.

Light-Chain Amyloidosis: The Great Impostor

Light-chain amyloidosis (AL) is a disease of protean manifestations due to a wide spectrum of organs that can be affected. The disorder is caused by the deposition of an extracellular amorphous material, the amyloid, which is produced by malignant plasma cells. The latter usually reside in the bone marrow; plasma cell infiltration is often low, in sharp contrast to what we observe in multiple myeloma. The disease may run below the physician's radar for a while before clinical suspicion is raised and targeted tests are performed. In this short review, we try to answer most of the questions that a practicing physician may ask in a relative clinical setting. The text is formed as a series of reader-friendly questions that cover the subject of AL amyloidosis from history to current therapy.

Emerging therapeutic avenues in cardiac amyloidosis

Cardiac Amyloidosis (CA) is a toxic infiltrative cardiomyopathy occurred by the deposition of the amyloid fibres in the extracellular matrix of the myocardium. This results in severe clinical complications such as increased left ventricular wall thickness and interventricular stiffness, a decrease in left ventricular stroke volume and cardiac output, diastolic dysfunction, arrhythmia, etc. In a prolonged period, this condition progresses into heart failure. The amyloid fibres affecting the heart include immunoglobulin light chain (AL - amyloidosis) and transthyretin protein (ATTR - amyloidosis) misfolded amyloid fibres. ATTRwt has the highest prevalence of 155 to 191 cases per million while ATTRv has an estimated prevalence of 5.2 cases per million. The pathological findings and therapeutic approaches developed recently have aided in the treatment regimen of cardiac amyloidosis patients. In recent years, understanding the pathophysiology of amyloid fibres formation and mechanistic pathways triggered in both types of cardiac amyloidosis has led to the development of new therapeutic approaches and agents. This review focuses on the current status of emerging therapeutic agents in clinical trials. Earlier, melphalan and bortezomib in combination with alkylating agents and immunomodulatory drugs were used as a standard therapy for AL amyloidosis. Tafamidis, approved recently by FDA is used as a standard for ATTR amyloidosis. However, the emerging therapeutic agents under development for the treatment of AL and ATTR cardiac amyloidosis have shown a potent and rapid effect with a safety profile.

Human lysozyme inhibits the fibrillation of serum amyloid a protein from systemic AA amyloidosis

BACKGROUND

Systemic AA amyloidosis is a world-wide occurring protein misfolding disease in humans and animals that arises from the formation of amyloid fibrils from serum amyloid A (SAA) protein and their deposition in multiple organs.

OBJECTIVE

To identify new agents that prevent fibril formation from SAA protein and to determine their mode of action.

MATERIALS AND METHODS

We used a cell model for the formation of amyloid deposits from SAA protein to screen a library of peptides and small proteins, which were purified from human hemofiltrate. To clarify the inhibitory mechanism the obtained inhibitors were characterised in cell-free fibril formation assays and other biochemical methods.

RESULTS

We identified lysozyme as an inhibitor of SAA fibril formation. Lysozyme antagonised fibril formation both in the cell model as well as in cell-free fibril formation assays. The protein binds SAA with a dissociation constant of 16.5 ± 0.6 µM, while the binding site on SAA is formed by segments of positively charged amino acids.

CONCLUSION

Our data imply that lysozyme acts in a chaperone-like fashion and prevents the aggregation of SAA protein through direct, physical interactions.

Localized Amyloid A amyloidsis of ureter: A case report

Amyloidosis of the ureter is a rare disease, distinguishing it from a neoplasm is difficult. A 64-year-old Japanese woman suffered from macrohematuria and left side hydronephrosis with ultrasound in 2014. Retrograde pyelography revealed no ureter tumor at that time. The patient had macrohematuria, left side hydronephrosis, and ureteral stenosis in the left ureter on retrograde pyelography. She was suspected of having a ureter tumor when she was 71 years old in 2021. The patient underwent ureteroscopy with biopsy. Pathological specimens contained the amyloid A component, based on immunohistochemistry staining. We diagnosed the patient with amyloid A amyloidosis of the ureter.

Therapeutic effects of biological treatments on AA amyloidosis associated with inflammatory bowel disease: a case report and literature review

AA amyloidosis is a rare and significant complication of long-term inflammation that can be caused by a variety of disorders, including inflammatory bowel disease, and is linked to an increased risk of morbidity and mortality. To date, there has been no effective direct treatment, and treatment aims at treating the underlying condition with potent immunosuppression to limit inflammatory activity and, as a result, switch off amyloidogenesis. Theoretically, biological treatment can control AA amyloidosis by inducing and maintaining inflammatory bowel disease remission and inhibiting the synthesis of Serum Amyloid A, which is an acute phase reactant and precursor protein of AA amyloidosis that accumulates in the organs. We report the first case of ustekinumab's therapeutic effect after infliximab's loss of response in AA amyloidosis associated with Crohn's disease. We also conducted a literature review of the therapeutic effect of biological treatment on AA amyloidosis.

Treat-to-target strategies for the management of familial Mediterranean Fever in children

BACKGROUND

The objective of this initiative was to develop a treat-to-target (T2T) approach for the management of patients with Familial Mediterranean Fever (FMF), including the definition of a complex treatment target, and establish strategies that improve patient care and long-term outcome.

METHODS

An initial set of statements as well as a flow chart visualising the proposed concept was developed. To adapt the preliminary statements to the current state of knowledge, a systematic literature search was performed and the modified statements were subject to a Delphi approach. To ensure the applicability of the statements in daily practice, an online survey was conducted among paediatric rheumatologists in Germany. In addition, data from the national AID-NET registry were analysed with respect to therapeutic response.

RESULTS

This T2T initiative yielded a total of 26 statements guiding FMF management with respect to diagnosis, treatment targets, treatment strategies and monitoring. The online survey identified cut-off values for inflammatory markers indicating treatment intensification and appropriate measures in case of colchicine intolerance or non-adherence. The analysis of data derived from the national AID-NET showed that colchicine therapy was successfully terminated in 61% of patients (27 out of 44) with heterozygous MEFV mutations. Multidimensional treatment targets incorporating objective and subjective reported outcome measures were developed. These provide the basis for stratifying patients into the following treatment paths: continue colchicine, persisting attacks / inflammation, colchicine intolerance, persisting arthritis, colchicine reduction and adjustment/reduction of biologics.

CONCLUSIONS

The proposed consensus treatment plan for the management of FMF incorporates multidimensional targets allowing transparent treatment decisions, which will promote personalised disease management and increase adherence to therapy.

Nephrotic Syndrome in a Retroviral Disease Due to AA Amyloidosis: A Rare Presentation

Kidney disease poses a significant burden on individuals with HIV infection. In the pre-ART era, HIV-associated nephropathy (HIVAN) was the most common renal pathology identified in individuals with HIV. However, the widespread use of ART has led to changes in the spectrum of renal pathologies associated with HIV. HIV infection is an unclear cause of AA amyloidosis. Here, we report a rare case of an HIV-positive patient presenting with nephrotic syndrome which turned out to be AA amyloidosis on renal biopsy.

Vector autoregression: Useful in rare diseases?-Predicting organ response patterns in a rare case of secondary AA amyloidosis

BACKGROUND

Statistical analyses of clinical data are a cornerstone in understanding pathomechanisms of disorders. In rare disorders, cross-sectional datasets of sufficient size are usually not available. Taking AA amyloidosis as an example of a life-threatening rare disorder resulting from of uncontrolled chronic inflammation, we propose techniques from time series analysis to predict organ response to treatment. The advantage of time-series analysis is that it solely relies on temporal variation and therefore allows analyzing organ response to treatment even when the cross-sectional dimension is small.

METHODS

The joint temporal interdependence of inflammatory activity and organ response was modelled multivariately using vector autoregression (VAR) based on a unique 4.5 year spanning data set of routine laboratory, imaging data (e.g., 18F-Florbetaben-PET/CT) and functional investigations of a 68-year-old patient with multi-organ involvement of AA amyloidosis due to ongoing inflammatory activity of a malignant paraganglioma in stable disease for >20 years and excellent response to tocilizumab).

RESULTS

VAR analysis showed that alterations in inflammatory activity forecasted alkaline phosphatase (AP). AP levels, but not inflammatory activity at the previous measurement time point predicted proteinuria.

CONCLUSION

We demonstrate the feasibility and value of time series analysis for obtaining clinically reliable information when the rarity of a disease prevents conventional prognostic modelling approaches. We illustrate the comparative utility of blood, functional and imaging markers to monitor the development and regression of AA amyloidosis.

Glomerulonephritis: immunopathogenesis and immunotherapy

'Glomerulonephritis' (GN) is a term used to describe a group of heterogeneous immune-mediated disorders characterized by inflammation of the filtration units of the kidney (the glomeruli). These disorders are currently classified largely on the basis of histopathological lesion patterns, but these patterns do not align well with their diverse pathological mechanisms and hence do not inform optimal therapy. Instead, we propose grouping GN disorders into five categories according to their immunopathogenesis: infection-related GN, autoimmune GN, alloimmune GN, autoinflammatory GN and monoclonal gammopathy-related GN. This categorization can inform the appropriate treatment; for example, infection control for infection-related GN, suppression of adaptive immunity for autoimmune GN and alloimmune GN, inhibition of single cytokines or complement factors for autoinflammatory GN arising from inborn errors in innate immunity, and plasma cell clone-directed or B cell clone-directed therapy for monoclonal gammopathies. Here we present the immunopathogenesis of GN and immunotherapies in use and in development and discuss how an immunopathogenesis-based GN classification can focus research, and improve patient management and teaching.

Renal involvement in monogenic autoinflammatory diseases: A narrative review

Autoinflammatory diseases (AIDs) are mostly caused by dysfunctions in single genes encoding for proteins with a prominent role in the regulation of innate immunity, such as complement factors, inflammasome components, tumour necrosis factor (TNF)-α, and proteins belonging to type I-interferon (IFN) signalling pathways. Due to the deposition of amyloid A (AA) fibrils in the glomeruli, unprovoked inflammation in AIDs frequently affects renal health. In fact, secondary AA amyloidosis is the most common form of amyloidosis in children. It is caused by the extracellular deposition of fibrillar low-molecular weight protein subunits resulting from the degradation and accumulation of serum amyloid A (SAA) in numerous tissues and organs, primarily the kidneys. The molecular mechanisms underlying AA amyloidosis in AIDs are the elevated levels of SAA, produced by the liver in response to pro-inflammatory cytokines, and a genetic predisposition due to specific SAA isoforms. Despite the prevalence of amyloid kidney disease, non-amyloid kidney diseases may also be responsible for chronic renal damage in children with AIDs, albeit with distinct characteristics. Glomerular damage can result in various forms of glomerulonephritis with distinct histologic characteristics and a different underlying pathophysiology. This review aims to describe the potential renal implications in patients with inflammasomopathies, type-I interferonopathies, and other rare AIDs in an effort to improve the clinical course and quality of life in paediatric patients with renal involvement.

Lymphangioleiomyomatosis and Other Cystic Lung Diseases

Cysts and cavities in the lung are commonly encountered on chest imaging. It is necessary to distinguish thin-walled lung cysts (≤2 mm) from cavities and characterize their distribution as focal or multifocal versus diffuse. Focal cavitary lesions are often caused by inflammatory, infectious, or neoplastic processes in contrast to diffuse cystic lung diseases. An algorithmic approach to diffuse cystic lung disease can help narrow the differential diagnosis, and additional testing such as skin biopsy, serum biomarkers, and genetic testing can be confirmatory. An accurate diagnosis is essential for the management and disease surveillance of extrapulmonary complications.

Rapid Clinical Improvement of Multicentric Castleman Disease (MCD) with Renal Involvement Following Treatment with Tocilizumab: AA Amyloidosis as a Possible Renal Involvement of MCD

Castleman disease (CD) is a lymphoproliferative disorder that manifests as hypergammaglobulinemia and severe inflammation with multiorgan involvement. However, renal involvement has been infrequently described in CD. We present a case of a 63-year-old Japanese male patient with multicentric CD (MCD) in whom kidney involvement, including impaired renal function and massive proteinuria, is present. He had a 2-year history of inflammatory arthritis and was referred to our clinic with newly developed proteinuria, renal dysfunction, and elevated levels of acute-phase proteins. Abdominal computed tomography scan revealed hepatosplenomegaly, including mesenteric and inguinal lymph node enlargements. The patient underwent inguinal lymph node resection. Excisional biopsy of the inguinal lymph node showed multiple lymphoid follicles and expansion of interfollicular areas by marked plasmacytosis consistent with mixed type CD. The patient was diagnosed with human herpes virus 8-negative MCD according to the international diagnostic criteria for CD. Diagnostic renal biopsy was not performed following the medical viewpoint. Tocilizumab (TCZ) treatment was highly effective in reducing proteinuria and stabilizing renal function, as well as improving other clinical symptoms. The patient responded to TCZ treatment, and the renal involvement was rapidly improved. Our preliminary immunohistochemical analysis indicated AA amyloid deposits in urinary epithelial cells suggesting a possible renal involvement of AA amyloidosis. TCZ could potentially be one of the therapeutic options in patients with MCD with renal involvement.

Localized Rectal Amyloidosis with Morphologic Changes from the Submucosal Tumor to the Ulcerative Lesion That Led to Hematochezia During Observation

A 75-year-old woman visited our hospital with constipation. Colonoscopy revealed a submucosal tumor in the rectum. She was followed up as a case of mucosal prolapse syndrome. Six years later, she was referred to our hospital due to hematochezia and abdominal pain. Colonoscopy revealed that the submucosal tumor had an ulcerative appearance with bleeding. Low anterior resection was performed. Amyloid protein deposition was detected from the submucosa to subserosa. Other organs showed no evidence of amyloidosis; we therefore diagnosed the patient with localized rectal amyloidosis. This is a rare case of symptomatic localized rectal amyloidosis whose long-term progression was able to be endoscopically observed.

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.

Renal AA amyloidosis: presentation, diagnosis, and current therapeutic options: a review

Amyloid A amyloidosis is thought to be the second most common form of systemic amyloidosis behind amyloidosis secondary to monoclonal Ig. It is the result of deposition of insoluble fibrils in the extracellular space of tissues and organs derived from the precursor protein serum amyloid A, an acute phase reactant synthesized excessively in the setting of chronic inflammation. The kidney is the most frequent organ involved. Most patients present with proteinuria and kidney failure. The diagnosis is made through tissue biopsy with involvement of the glomeruli in most cases, but also often of the vessels and the tubulointerstitial compartment. The treatment usually targets the underlying etiology and consists increasingly of blocking the inflammatory cascade of cytokines with interleukin-1 inhibitors, interleukin-6 inhibitors, and tumor necrosis factor-α inhibitors to reduce serum amyloid A protein formation. This strategy has also shown efficacy in cases where an underlying etiology cannot be readily identified and has significantly improved the prognosis of this entity. In addition, there has been increased interest at developing effective therapies able to clear amyloid deposits from tissues, albeit with mitigated results so far.

Heme oxygenase-1 deficiency as an extremely rare cause of AA-type renal amyloidosis: Expanding the clinical features and review of the literature

Heme oxygenase-1 (HMOX-1) is an enzyme that regulates heme degradation. Antiinflammatory, antioxidant, and cytoprotective effects of HMOX-1 were also described. It is encoded by the HMOX1 gene, and biallelic mutations cause HMOX-1 deficiency, which is a rare chronic multisystemic inflammatory disorder. This inflammatory status could lead to the development of secondary AA-type amyloidosis theoretically. Here, we report a 30-year-old male with AA-type renal amyloidosis due to a chronic inflammatory condition of unknown origin. Paternal consanguinity and dysmorphic features raised suspicion of a rare genetic disorder. Clinical exome sequencing (CES) confirmed the HMOX-1 deficiency diagnosis related to homozygous missense G139V mutation. To the best of our knowledge, our patient is the eleventh HMOX-1 deficiency case in the literature. Also, HMOX-1 deficiency-related systemic AA-type amyloidosis has not been reported before.

French practical guidelines for the diagnosis and management of AA amyloidosis

AA amyloidosis is secondary to the deposit of excess insoluble Serum Amyloid A (SAA) protein fibrils. AA amyloidosis complicates chronic inflammatory diseases, especially chronic inflammatory rheumatisms such as rheumatoid arthritis and spondyloarthritis; chronic infections such as tuberculosis, bronchectasia, chronic inflammatory bowel diseases such as Crohn's disease; and auto-inflammatory diseases including familial Mediterranean fever. This work consists of the French guidelines for the diagnosis workup and treatment of AA amyloidosis. We estimate in France between 500 and 700 cases in the whole French population, affecting both men and women. The most frequent organ impaired is kidney which usually manifests by oedemas of the lower extremities, proteinuria, and/or renal failure. Patients are usually tired and can display digestive features anf thyroid goiter. The diagnosis of AA amyloidosis is based on detection of amyloid deposits on a biopsy using Congo Red staining with a characteristic green birefringence in polarized light. Immunohistochemical analysis with an antibody directed against Serum Amyloid A protein is essential to confirm the diagnosis of AA amyloidosis. Peripheral inflammatory biomarkers can be measured such as C Reactive protein and SAA. We propose an algorithm to guide the etiological diagnosis of AA amyloidosis. The treatement relies on the etiologic treatment of the undelying chronic inflammatory disease to decrease and/or normalize Serum Amyloid A protein concentration in order to stabilize amyloidosis. In case of renal failure, dialysis or even a kidney transplant can be porposed. Nowadays, there is currently no specific treatment for AA amyloidosis deposits which constitutes a therapeutic challenge for the future.

Amyloid Protein Cross-Seeding Provides a New Perspective on Multiple Diseases In Vivo

Amyloid protein cross-seeding is a peculiar phenomenon of cross-spreading among different diseases. Unlike traditional infectious ones, diseases caused by amyloid protein cross-seeding are spread by misfolded proteins instead of pathogens. As a consequence of the interactions among misfolded heterologous proteins or polypeptides, amyloid protein cross-seeding is considered to be the crucial cause of overlapping pathological transmission between various protein misfolding disorders (PMDs) in multiple tissues and cells. Here, we briefly review the phenomenon of cross-seeding among amyloid proteins. As an interesting example worth mentioning, the potential links between the novel coronavirus pneumonia (COVID-19) and some neurodegenerative diseases might be related to the amyloid protein cross-seeding, thus may cause an undesirable trend in the incidence of PMDs around the world. We then summarize the theoretical models as well as the experimental techniques for studying amyloid protein cross-seeding. Finally, we conclude with an outlook on the challenges and opportunities for basic research in this field. Cross-seeding of amyloid opens up a new perspective in our understanding of the process of amyloidogenesis, which is crucial for the development of new treatments for diseases. It is therefore valuable but still challenging to explore the cross-seeding system of amyloid protein as well as to reveal the structural basis and the intricate processes.

Down-regulated Th17 cells in a patient with familial Mediterranean fever associated with amyloid A amyloidosis in the treatment of canakinumab

Autoinflammatory diseases are innate immune-mediated inflammatory disorders, unlike autoimmune diseases, which are characterised by abnormalities in adoptive immunity, although autoimmune and autoinflammatory diseases have certain similar clinical features. Familial Mediterranean fever (FMF), the most common monogenic autoinflammatory disease, is associated with mutations in the MEFV gene that encodes pyrin, which results in inflammasome activation and uncontrolled production of interleukin (IL)-1β. Regular use of colchicine, the primary drug for FMF treatment, prevents febrile attacks and reduces the long-term risk of subsequent complications of amyloid A (AA) amyloidosis. However, a minority of FMF patients develop colchicine resistance, and anti-IL-1β treatment with canakinumab, which is a genetically modified human IgG subclass type 1 (IgG1) monoclonal antibody specific for human IL-1β, was beneficial in inhibiting inflammation in such patients. Here, we present a patient with FMF associated with AA amyloidosis, who was treated with canakinumab and demonstrated down-regulated Th17 cells and activated Th17 cells (from 21.4% to 12.8%, and from 1.45% to 0.83%, respectively) in peripheral blood, as shown by immunophenotyping via multicolour flow cytometry and by disease activity and improved laboratory inflammatory surrogate markers-C-reactive protein (CRP) and serum AA protein (SAA). CRP had values within normal limits, but SAA did not (Spearman's rank correlation coefficient; ρ = 0.133). We report that SAA and IL-1β may differentiate Th17 cells from CD4+-naïve T cells, and we discuss interactions between autoinflammation and autoimmunity as a model based on this case, through modes of action with IL-1β and SAA. This report is the first demonstrating that an IL-1β antagonist may reduce Th17 cells in FMF as a therapeutic option.

Frequency of AA amyloidosis has decreased in Behçet's syndrome: a retrospective study with long-term follow-up and a systematic review

OBJECTIVE

A decline in the frequency of AA amyloidosis secondary to RA and infectious diseases has been reported. We aimed to determine the change in the frequency of AA amyloidosis in our Behçet's syndrome (BS) patients and to summarize the clinical characteristics of and outcomes for our patients, and also those identified by a systematic review.

METHODS

We identified patients with amyloidosis in our BS cohort (as well as their clinical and laboratory features, treatment, and outcome) through a chart review. The primary end points were end-stage renal disease and death. The prevalence of AA amyloidosis was estimated separately for patients registered during 1976-2000 and those registered during 2001-2017, in order to determine whether there was any change in the frequency. We searched PubMed and EMBASE for reports on BS patients with AA amyloidosis. Risk of bias was assessed using the Grading of Recommendations Assessment, Development and Evaluation (GRADE) tool.

RESULTS

The prevalence of AA amyloidosis was 0.62% (24/3820) in the earlier cohort and declined to 0.054% (3/5590) in the recent cohort. The systematic review revealed 82 cases in 42 publications. The main features of patients were male predominance and a high frequency of vascular involvement. One-third of patients died within 6 months after diagnosis of amyloidosis.

CONCLUSION

The frequency of AA amyloidosis has decreased in patients with BS, which is similar to the decrease observed for AA amyloidosis due to other inflammatory and infectious causes. However, AA amyloidosis is a rare, but potentially fatal complication of BS.

Current Understanding of Systemic Amyloidosis and Underlying Disease Mechanisms

Amyloidosis is a group of diverse disorders caused by misfolded proteins that aggregate into insoluble fibrils and ultimately cause organ damage. In medical practice, amyloidosis classification is based on the amyloid precursor protein type, of which amyloid immunoglobulin light chain, amyloid transthyretin, amyloid leukocyte chemotactic factor 2, and amyloid derived from serum amyloid A protein are the most common. Distinct mechanisms appear to be predominantly operational in the pathogenesis of particular types of amyloidosis, including increased protein precursor synthesis, somatic or germ line mutations, and inherent instability in the precursor protein in its wild form. An increased supply of misfolded proteins and/or a decreased capacity of the protein quality control systems can result in an imbalance that leads to increased circulation of misfolded proteins. Although the detection of mature fibrils is the basis for diagnosis of amyloidosis, a growing body of evidence has implicated the prefibrillar species as proteotoxic and key contributors to the development of the disease.

[Bladder AA amyloidosis: A rare location. About a case]

INTRODUCTION

Bladder localization of AA amyloidosis is rare. It can be responsible for massive and recurrent hematuria. We report a case of bladder AA amyloidosis secondary to Crohn's disease in a renal transplant patient.

CLINICAL OBSERVATION

A 62-year-old man, suffering from Crohn's disease since 1991 complicated by renal AA amyloidosis. He received a kidney transplant since 20 years from an HLA identical donor. After an 18-year period of clinical remission, the patient was admitted for a flare-up of his Crohn's disease in the form of intermittent diarrhoea. Treatment with corticosteroids allowed a good evolution. A year later, he was rehospitalized for massive macroscopic haematuria. Histological examination of the bladder biopsy revealed AA amyloidosis. The patient fully recovered but died 6 weeks later from septic shock of urinary origin.

CONCLUSION

The treatment of bladder localization of AA amyloidosis is based on treating the cause. Hematuria is sometimes massive, exceptionally requiring emergency cystectomy for haemostasis.

Noninvasive Diagnostics of Renal Amyloidosis: Current State and Perspectives

Amyloidoses is a group of diseases characterized by the accumulation of abnormal proteins (called amyloids) in different organs and tissues. For systemic amyloidoses, the disease is related to increased levels and/or abnormal synthesis of certain proteins in the organism due to pathological processes, e.g., monoclonal gammopathy and chronic inflammation in rheumatic arthritis. Treatment of amyloidoses is focused on reducing amyloidogenic protein production and inhibition of its aggregation. Therapeutic approaches critically depend on the type of amyloidosis, which underlines the importance of early differential diagnostics. In fact, the most accurate diagnostics of amyloidosis and its type requires analysis of a biopsy specimen from the disease-affected organ. However, absence of specific symptoms of amyloidosis and the invasive nature of biomaterial sampling causes the late diagnostics of these diseases, which leads to a delayed treatment, and significantly reduces its efficacy and patient survival. The establishment of noninvasive diagnostic methods and discovery of specific amyloidosis markers are essential for disease detection and identification of its type at earlier stages, which enables timely and targeted treatment. This review focuses on current approaches to the diagnostics of amyloidoses, primarily with renal involvement, and research perspectives in order to design new specific tests for early diagnosis.

Amyloidosis from the patient perspective: the French daily impact of amyloidosis study

BACKGROUND

Amyloidosis is a complex group of rare conditions. For patients, amyloidosis is severely debilitating: physically and psychologically. Currently, data are lacking to evaluate the medical, economic, and social burden of systemic amyloidosis.

OBJECTIVE

To analyse the patient burden according to the main types of systemic amyloidosis.

METHODS

The French Daily Impact of Amyloidosis study was an observational, cross-sectional and non-interventional study. Adults diagnosed with light chain (AL), transthyretin (ATTR), amyloid A (AA) and other rare forms of amyloidosis were eligible. Data regarding amyloidosis prevalence, diagnosis, management, and impact on everyday life were collected using a study-specific survey built by the Association Française Contre l'Amylose (AFCA) and the four French National Referral Centres for Amyloidosis.

RESULTS

A total of 603 patients, predominantly male (65%) with an average age of 66.8 years, including 170 AL, 224 ATTRv, 109 ATTRwt and 25 AA amyloidosis patients, completed the study-specific survey. The median delay from presentation to confirmed diagnosis was 27.4 months but varied according to amyloidosis type. Patients before diagnosis had breathlessness (49%), tingling sensation (33%), pain (28%), difficulty in walking (28%) and weight loss (22%). Amyloidosis was most frequently suspected (49%) and confirmed (57%) in local hospitals but managed in French amyloidosis referral centres (58%). Patients often reported problems with mobility, usual activities, pain/discomfort and anxiety/depression, but not with self-care.

CONCLUSIONS

Systemic amyloidosis severely impacts daily life. The delay to confirmed amyloidosis diagnosis needs to be reduced. Early, effective treatment is required to optimise patient benefits.

Investigation of the relationship between disease severity and development of amyloidosis and genetic mutation in FMF disease

BACKGROUND

Familial Mediterranean fever (FMF) is an autosomal recessive genetic disease. Amyloidosis is the most important complication of FMF that determines the prognosis of the disease.

AIMS

In our study, we have investigated the relationship between the genetic mutations with the disease severity and the frequency of development of amyloidosis inpatients with FMF.

METHODS

A total of 148 patients with FMF were included this study. The relationship between disease activity score, clinical findings, response to treatment, and presence of amyloid and genetic mutations were evaluated.

RESULTS

One hundred forty-eight patients (80 women (54%), 68 men (46%)) were enrolled over 18 years of age. The mean age of the patients was 30.98 ± 11.18 (18-67) years. In our study, the most frequently seen mutations are M694V, M680I, R202Q, and E148Q, respectively. The most common genotype is M694V/M694V mutation and this mutation has been found in 37 patients (25%). In 25 patients, M694V heterozygous have been found (16.8%). The third frequent mutationis M694V/M680I/R202Q has been found in13 patients (8.7%). In 23 patients, amyloidosis has been developed. Ten patients with amyloidosis have M694V homozygous mutations (27%) and 5 patients with amyloidosis M694V heterozygous (20%) mutations. The both of the two patients who carry the homozygous E148Q mutations have developed amyloidosis.

CONCLUSIONS

In our study, the distribution of the frequency of mutations is consistent with other similar studies performed in Turkey. We found that patients with M694V mutation had a significantly higher rate of exacerbation, higher drug doses for treatment, and a close relationship with amyloidosis, as compared to patients with other mutations.

Unmet Medical Needs in Chronic, Non-communicable Inflammatory Skin Diseases

An estimated 20-25% of the population is affected by chronic, non-communicable inflammatory skin diseases. Chronic skin inflammation has many causes. Among the most frequent chronic inflammatory skin diseases are atopic dermatitis, psoriasis, urticaria, lichen planus, and hidradenitis suppurativa, driven by a complex interplay of genetics and environmental factors. Autoimmunity is another important cause of chronic skin inflammation. The autoimmune response may be mainly T cell driven, such as in alopecia areata or vitiligo, or B cell driven in chronic spontaneous urticaria, pemphigus and pemphigoid diseases. Rare causes of chronic skin inflammation are autoinflammatory diseases, or rheumatic diseases, such as cutaneous lupus erythematosus or dermatomyositis. Whilst we have seen a significant improvement in diagnosis and treatment, several challenges remain. Especially for rarer causes of chronic skin inflammation, early diagnosis is often missed because of low awareness and lack of diagnostics. Systemic immunosuppression is the treatment of choice for almost all of these diseases. Adverse events due to immunosuppression, insufficient therapeutic responses and relapses remain a challenge. For atopic dermatitis and psoriasis, a broad spectrum of innovative treatments has been developed. However, treatment responses cannot be predicted so far. Hence, development of (bio)markers allowing selection of specific medications for individual patients is needed. Given the encouraging developments during the past years, we envision that many of these challenges in the diagnosis and treatment of chronic inflammatory skin diseases will be thoroughly addressed in the future.

Proteomic Signatures of Monocytes in Hereditary Recurrent Fevers

Hereditary periodic recurrent fevers (HRF) are monogenic autoinflammatory associated to mutations of some genes, such as diseases caused by mutations of including MEFV, TNFRSF1A and MVK genes. Despite the identification of the causative genes, the intracellular implications related to each gene variant are still largely unknown. A large –scale proteomic analysis on monocytes of these patients is aimed to identify with an unbiased approach the mean proteins and molecular interaction networks involved in the pathogenesis of these conditions. Monocytes from HRF 15 patients (5 with MFV, 5 TNFRSF1A and 5with MVK gene mutation) and 15 healthy donors (HDs) were analyzed by liquid chromatography and tandem mass spectrometry before and after lipopolysaccharide (LPS) stimulation. Significant proteins were analyzed through a Cytoscape analysis using the ClueGo app to identify molecular interaction networks. Protein networks for each HRF were performed through a STRING database analysis integrated with a DISEAE database query. About 5000 proteins for each HRF were identified. LPS treatment maximizes differences between up-regulated proteins in monocytes of HRF patients and HDs, independently from the disease’s activity and ongoing treatments. Proteins significantly modulated in monocytes of the different HRF allowed creating a disease-specific proteomic signatures and interactive protein network. Proteomic analysis is able to dissect the different intracellular pathways involved in the inflammatory response of circulating monocytes in HRF patients. The present data may help to identify a “monocyte proteomic signature” for each condition and unravel new possible unexplored intracellular pathways possibly involved in their pathogenesis. These data will be also useful to identify possible differences and similarities between the different HRFs and some multifactorial recurrent fevers.

Assessment of Surrogate Markers for Cardiovascular Disease in Familial Mediterranean Fever-Related Amyloidosis Patients Homozygous for M694V Mutation in MEFV Gene

Cardiovascular disease (CVD) remains underestimated in familial Mediterranean fever-associated AA amyloidosis (FMF-AA). We aimed to compare early markers of endothelial dysfunction and atherosclerosis in FMF-AA with a homozygous M694V mutation (Group 1 = 76 patients) in the Mediterranean fever (MEFV) gene and in patients with other genotypes (Group 2 = 93 patients). Measures of increased risk for future CVD events and endothelial dysfunction, including flow-mediated dilatation (FMD), pentraxin-3 (PTX3), and carotid intima-media thickness (cIMT), and fibroblast growth factor 23 (FGF23) as a marker of atherosclerotic vascular disease were compared between groups. The frequency of clinical FMF manifestations did not differ between the two groups apart from arthritis (76.3% in Group 1 and 59.1% in Group 2, p < 0.05). FMD was significantly lower in Group 1 when compared with Group 2 (MD [95% CI]: −0.6 [(−0.89)−(−0.31)]). cIMT, FGF23, and PTX3 levels were higher in Group 1 (cIMT MD [95% CI]: 0.12 [0.08−0.16]; FGF23 MD [95% CI]: 12.8 [5.9−19.6]; PTX3 MD [95% CI]: 13.3 [8.9−17.5]). In patients with FMF-AA, M694V homozygosity is associated with lower FMD values and higher cIMT, FGF23, and PTX3 levels, suggesting increased CVD risk profiles. These data suggest that a genotype−phenotype association exists in terms of endothelial dysfunction and atherosclerosis in patients with FMF-AA.

A stepwise data interpretation process for renal amyloidosis typing by LMD-MS

Backgrounds

Systemic amyloidosis is classified according to the deposited amyloid fibril protein (AFP), which determines its best therapeutic scheme. The most common type of AFP found are immunoglobulin light chains. The laser microdissection combined with mass spectrometry (LMD-MS) technique is a promising approach for precise typing of amyloidosis, however, the major difficulty in interpreting the MS data is how to accurately identify the precipitated AFP from background.

Objectives

The objective of the present study is to establish a complete data interpretation procedure for LMD-MS based amyloidosis typing.

Methods

Formalin-fixed paraffin-embedded specimens from patients with renal amyloidosis and non-amyloid nephropathies (including diabetic nephropathy, fibrillary glomerulonephritis, IgA nephropathy, lupus nephritis, membranous nephropathy, and normal tissue adjacent to tumors) were analyzed by LMD-MS. Forty-two specimens were used to train the data interpretation procedure, which was validated by another 50 validation specimens. Area under receiver operating curve (AUROC) analysis of amyloid accompanying proteins (AAPs, including apolipoprotein A-IV, apolipoprotein E and serum amyloid P-component) for discriminating amyloidosis from non-amyloid nephropathies was performed.

Results

A stepwise data interpretation procedure that includes or excludes the types of amyloidosis group by group was established. The involvement of AFPs other than immunoglobulin was determined by P-score, as well as immunoglobulin light chain by variable of λ-κ, and immunoglobulin heavy chain by H-score. This achieved a total of 88% accuracy in 50 validation specimens. The AAPs showed significantly different expression levels between amyloidosis specimens and non-amyloid nephropathies. Each of the single AAP had a AUROC value more than 0.9 for diagnosis of amyloidosis from non-amyloid control, and the averaged level of the three AAPs showed the highest AUROC (0.966), which might be an alternative indicator for amyloidosis diagnosis.

Conclusions

The proteomic data interpretation procedure for LMD-MS based amyloidosis typing was established successfully that has a high practicability in clinical application.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12882-022-02785-9.

Renal Amyloidosis: A Clinicopathological Study From a Tertiary Care Hospital in Pakistan

Introduction

Systemic amyloidosis can affect any organ in the body, but the kidney is the most commonly involved site. It is characterized by the extracellular deposition of insoluble fibrillar proteins. Amyloid deposits can be identified histologically by Congo red stain, which gives apple-green birefringence under polarized light. Typing of renal amyloidosis is done by direct immunofluorescence on frozen tissue. The most common types of amyloidosis seen in renal tissue are amyloid light chain (AL) primary amyloidosis and amyloid A (AA) secondary amyloidosis. Although primary amyloidosis is considered the most common type in western countries, however, in the subcontinent region, secondary amyloidosis is more common.

The spectrum of signs and symptoms in renal amyloidosis is variable including isolated proteinuria, nephrotic syndrome, hypertension, hypotension, and renal insufficiency. The present study aims to evaluate the incidence and aetiology of various types of renal amyloidosis, determine their distribution within the kidney, and study various clinicopathological features.

Objective

The present study aims to evaluate the aetiology and clinicopathological profile of renal amyloidosis, determine its various types, and their distribution within the kidney.

Materials and methods

This retrospective cross-sectional study was conducted from 1st January 2013 to 31st December 2020 at the Department of Histopathology, Shifa International Hospital (SIH), Islamabad. All renal biopsies diagnosed as renal amyloidosis were included in the study. Data were analysed using SPSS version 23 (IBM Corp., Armonk, NY). Frequency and percentages were calculated for qualitative variables, and mean and standard deviation were calculated for quantitative variables.

Results

A total of 131 cases were diagnosed with renal amyloidosis during the study period of eight years (from 1st January 2013 to 31st December 2020) at SIH. The age range varied from 17 to 82 years. The mean age of the patients was 45 ± 16.33 years. Out of 131 patients, 82 (62.6%) were males and 49 (37.4%) were females. Amongst them, 72 (54%) cases were diagnosed with secondary AA amyloidosis and 16 (12%) cases were diagnosed with primary AL amyloidosis. The rest of the cases 43 (34%) were of indeterminate type. The associated conditions in secondary amyloidosis were tuberculosis in 41 (57%), rheumatoid arthritis in 16 (22%), ankylosing spondylitis in five (7%), lymphoma in three (4%), diabetes in two (3%), and chronic osteomyelitis, chronic heart disease, hepatitis, and vasculitis in one case each (1.7%). Out of 16 cases reported with AL amyloidosis, 10 cases (62.5%) had a history of multiple myeloma. The most common clinical presentation was nephrotic syndrome followed by subnephrotic proteinuria, renal failure, and hypertension.

Conclusion

The findings of the present study show underlying etiological factors and clinicopathological characteristics of renal amyloidosis. AA amyloidosis is the most common type of renal amyloidosis in our study and tuberculosis is the most common aetiological factor. AL amyloidosis is less frequent in our population.

Potential therapeutic targets to prevent organ damage in chronic pulmonary sarcoidosis

INTRODUCTION

Sarcoidosis is a granulomatous inflammatory disease with high chances of reduced quality of life, irreversible organ damage, and reduced life expectancy when vital organs are involved. Any organ system can be affected, and the lungs are most often affected. There is no preventive strategy as the exact etiology is unknown, and complex immunogenetic and environmental factors determine disease susceptibility and phenotype. Present-day treatment options originated from clinical practice and are effective in many patients. However, a substantial percentage of patients suffer from unacceptable side effects or still develop refractory, threatening pulmonary or extrapulmonary disease.

AREAS COVERED

As non-caseating granulomas, the pathological hallmark of disease, are assigned to divergent activation and regulation of the immune system, targets in relation to the possible triggers of granuloma formation and their sequelae were searched and reviewed.

EXPERT OPINION

:The immunopathogenesis underlying sarcoidosis has been a dynamic field of study. Several recent new insights give way to promising new therapeutic targets, such as certain antigenic triggers (e.g. from Aspergillus nidulans), mTOR, JAK-STAT and PPARγ pathways, the NRP2 receptor and MMP-12, which await further exploration. Clinical and trigger related phenotyping, and molecular endotyping in sarcoidosis will likely hold the key for precision medicine in the future.

[A rare cause of AA amyloidosis: Hereditary epidermolysis bullosa]

INTRODUCTION

Recessive dystrophic epidermolysis bullosa is a rare genetic condition characterized by fragile skin and mucous membrane, caused by mutations in the COL7A1 gene. AA amyloidosis is a rare complication of these genodermatosis.

OBSERVATIONS

Two patients with recessive dystrophic epidermolysis bullosa, generalized severe in the first case and generalized intermediate in the second case, developed at the age of 38 and 28, respectively, nephrotic syndrome. The diagnosis of secondary renal amyloidosis was confirmed by renal biopsy in the first case and by minor salivary gland biopsy in the second case. Death occurred 2 months after diagnosis in both cases.

CONCLUSION

Renal involvement is quite common in AA amyloidosis in patients with recessive dystrophic epidermolysis bullosa. Nephrotic syndrome and rapid decline in renal function renal are characteristic features. The prognosis is poor due to underlying conditions and the lack of an etiological treatment.

Kidney Involvement in PSTPIP1 Associated Inflammatory Diseases (PAID): A Case Report and Review of the Literature

Pyogenic arthritis, pyoderma gangrenosum and acne (PAPA) syndrome, and the proline-serine-threonine phosphatase-interacting protein 1 (PSTPIP1)-associated myeloid-related proteinemia inflammatory (PAMI) syndrome are two distinct clinical conditions caused by heterozygous mutations of the PSTPIP1 gene. While skin and joint involvements are shared by both conditions, PAMI is characterized by hepatosplenomegaly, pancytopenia, and growth failure. Kidney involvement is exceptional in PSTPIP1-mediated disorders. The two missense PSTPIP1 variants associated with PAMI syndrome are p.E250K and p.E257K. Long-term treatment with interleukin (IL)-1 inhibitors is effective to control inflammatory manifestations and is usually well-tolerated. We report a case of a patient carrying the PSTPIP1 p.E250K mutation who developed a late-onset kidney involvement despite a long treatment with canakinumab and anakinra. Kidney biopsy showed focal segmental glomerulosclerosis that was treated with tacrolimus (0.1 mg/kg/day in two doses). A literature revision with the aim to assess the proportion and type of kidney involvement in PAMI syndrome revealed that heterogeneous nephropathies may be part of the clinical spectrum. Our study supports the importance of a periodic diagnostic work-up, including kidney laboratory tests and kidney biopsy, in individuals affected with PAMI syndrome. Kidney and liver functions may be impaired regardless of anti-cytokines treatments and additional therapy approaches (i.e., multi-drugs, hematopoietic stem cell transplantation) should be carefully considered.