Musculoskeletal pathology as an early warning sign of systemic amyloidosis: a systematic review of amyloid deposition and orthopedic surgery

Genetically transitional disease: conceptual understanding and applicability to rheumatic disease

In genomic medicine, the concept of genetically transitional disease (GTD) refers to cases in which gene mutation is necessary but not sufficient to cause disease. In this Perspective, we apply this novel concept to rheumatic diseases, which have been linked to hundreds of genetic variants via association studies. These variants are in the 'grey zone' between monogenic variants with large effect sizes and common susceptibility alleles with small effect sizes. Among genes associated with rare autoinflammatory diseases, many low-frequency and/or low-penetrance variants are known to increase susceptibility to systemic inflammation. In autoimmune diseases, hundreds of HLA and non-HLA genetic variants have been revealed to be modest- to moderate-risk alleles. These diseases can be reclassified as GTDs. The same concept could apply to many other human diseases. GTD could improve the reporting of genetic testing results, diagnostic yields, genetic counselling and selection of therapy, as well as facilitating research using a novel approach to human genetic diseases.

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.

Amyloidosis and Considerations for the Hand Surgeon

Amyloidosis can lead to cardiac, renal, and other multiorgan failure. New treatments have become available that can prolong survival but rely on early diagnosis. Manifestations of amyloidosis in hand surgery include carpal tunnel syndrome, trigger finger, peripheral neuropathy, and spontaneous distal biceps rupture. Often, these can predate systemic amyloidosis, offering hand surgeons an opportunity to diagnose patients with amyloidosis before systemic disease, refer them for treatment, and potentially alter disease course and prolong survival. In this review, we describe the pathophysiology and two most common subtypes of amyloidosis seen by hand surgeons. We provide guidance on biopsy practices and referral for patients with amyloidosis. Lastly, we provide a brief overview of the treatments for amyloidosis and their effect on disease course.

Rare vertebral pathological fracture in primary amyloidosis

Spinal involvement in primary amyloidosis is an exceedingly rare condition, presenting with typical pathological fracture symptoms that are often indistinguishable from other pathologies such as bone metastasis, metabolic disorders and infections. Histopathological studies for tissue diagnosis are the cornerstone of a definitive diagnosis, leading to successful treatment. Early diagnosis and intervention play a pivotal role in the care of patients with amyloidosis. Here, we present a unique case of a pathological fracture in the L4 vertebra following minor trauma. This fracture manifested with pain, instability and limitations in daily activities in a patient who had already been diagnosed with systemic amyloidosis and was undergoing chemotherapy. This case represents a distinct instance of vertebral involvement in amyloidosis and was managed with both chemotherapy and surgical intervention to address the spinal pathology, resulting in favourable outcomes.

Neuromuscular manifestations of wild type transthyretin amyloidosis: a review and single center's experience

Transthyretin amyloidosis (ATTR) is a condition defined by accumulation of insoluble transthyretin amyloid deposits in multiple organs, especially in the peripheral nerve and heart muscle. ATTR may result from transthyretin mutations (variant ATTR or ATTRv) or may occur with normal transthyretin genotype (wild type ATTR or ATTRwt). ATTRwt was previously known as "senile amyloidosis" and causes cardiomyopathy which may lead to heart failure with a preserved ejection fraction, affecting predominantly elderly men. The exact prevalence of ATTRwt in the general population remains unclear, but its occurrence may be underestimated in women. It was observed that a proportion of ATTRwt cardiomyopathy patients may develop slowly progressing neuropathy that is milder and indolent in comparison with typical progressive neuropathy associated with ATTRv. Furthermore, the causality of neuropathy is often uncertain in patients with ATTRwt. Neuropathy symptoms, including distal sensory loss, unsteadiness and (neuropathic) pain are common in elderly patients with multiple potential causes, and as ATTRwt patients are typically older, relatively high prevalence of peripheral neuropathy is expected with frequent comorbidities. Relatively high prevalence of ATTRwt in elderly population contrasts few documented cases of neuropathy caused by ATTRwt, and there is uncertainty whether ATTRwt neuropathy is an infrequent occurrence or a significant manifestation of multisystemic ATTRwt. We review neurologic and musculoskeletal manifestations of ATTRwt and present clinical features of a single center cohort of ATTRwt patients with suspected peripheral neuropathy.

Perioperative implications of amyloidosis and amyloid cardiomyopathy: A review for anesthesiologists

It is well recognized that amyloid protein can infiltrate many regions of the body. This can include the peripheral nerves, the liver, kidney, spleen, the gastrointestinal tract, and most importantly the myocardium. The amyloid proteins that cause cardiomyopathy may come from genetically altered liver genes (transthyretin amyloid, ATTR) or from the bone marrow with malignant plasma cells (light chain amyloid, AL) generating the aberrant protein. These two types of amyloidosis cause significant damaging effects on both the myocardial cells as well as the conduction system of the heart. The resultant changes can produce dyspnea and exercise intolerance which is thought to be secondary to diastolic dysfunction and reduced stroke volume. This subclinical decompensation poses a significant problem for members of a care team as it often goes unrecognized. In the operating room patients are exposed to dramatic hemodynamic changes and may have difficult airways, autonomic dysfunction, and conduction abnormalities. Although the topic of amyloidosis is well described in cardiology literature, it is underdiagnosed. The purpose of this review is to describe some of the pathophysiology behind the principle proteins that cause cardiac amyloidosis and to comprehensively describe perioperative considerations for anesthesia providers.

Hereditary transthyretin amyloidosis: a comprehensive review with a focus on peripheral neuropathy

Amyloidoses represent a group of diseases characterized by the pathological accumulation in the extracellular area of insoluble misfolded protein material called "amyloid". The damage to the tissue organization and the direct toxicity of the amyloidogenic substrates induce progressive dysfunctions in the organs involved. They are usually multisystem diseases involving several vital organs, such as the peripheral nerves, heart, kidneys, gastrointestinal tract, liver, skin, and eyes. Transthyretin amyloidosis (ATTR) is related to abnormalities of transthyretin (TTR), a protein that acts as a transporter of thyroxine and retinol and is produced predominantly in the liver. ATTR is classified as hereditary (ATTRv) and wild type (ATTRwt). ATTRv is a severe systemic disease of adults caused by mutations in the TTR gene and transmitted in an autosomal dominant manner with incomplete penetrance. Some pathogenic variants in TTR are preferentially associated with a neurological phenotype (progressive peripheral sensorimotor polyneuropathy); others are more frequently associated with restrictive heart failure. However, many mutations express a mixed phenotype with neurological and cardiological involvement. ATTRv is now a treatable disease. A timely and definite diagnosis is essential in view of the availability of effective therapies that have revolutionized the management of affected patients. The purpose of this review is to familiarize the clinician with the disease and with the correct diagnostic pathways in order to obtain an early diagnosis and, consequently, the possibility of an adequate treatment.

Musculoskeletal manifestations associated with transthyretin-mediated (ATTR) amyloidosis: a systematic review

BACKGROUND

Hereditary and wild-type transthyretin-mediated (ATTRv and ATTRwt) amyloidoses result from the misfolding of transthyretin and aggregation of amyloid plaques in multiple organ systems. Diagnosis of ATTR amyloidosis is often delayed due to its heterogenous and non-specific presentation. This review investigates the association of musculoskeletal (MSK) manifestations with ATTR amyloidosis and the delay from the onset of these manifestations to the diagnosis of ATTR amyloidosis.

METHODS

This systematic review utilized Medline and EMBASE databases. Search criteria were outlined using a pre-specified patient, intervention, comparator, outcome, time, study (PICOTS) criteria and included: amyloidosis, ATTR, and MSK manifestations. Publication quality was assessed utilizing Joanna Briggs Institute (JBI) critical appraisal checklists. The search initially identified 7,139 publications, 164 of which were included. PICOTS criteria led to the inclusion of epidemiology, clinical burden and practice, pathophysiology, and temporality of MSK manifestations associated with ATTR amyloidosis. 163 publications reported on ATTR amyloidosis and MSK manifestations, and 13 publications reported on the delay in ATTR amyloidosis diagnosis following the onset of MSK manifestations.

RESULTS

The MSK manifestation most frequently associated with ATTR amyloidosis was carpal tunnel syndrome (CTS); spinal stenosis (SS) and osteoarthritis (OA), among others, were also identified. The exact prevalence of different MSK manifestations in patients with ATTR amyloidosis remains unclear, as a broad range of prevalence estimates were reported. Moreover, the reported prevalence of MSK manifestations showed no clear trend or distinction in association between ATTRv and ATTRwt amyloidosis. MSK manifestations precede the diagnosis of ATTR amyloidosis by years, and there was substantial variation in the reported delay to ATTR amyloidosis diagnosis. Reports do suggest a longer diagnostic delay in patients with ATTRv amyloidosis, with 2 to 12 years delay in ATTRv versus 1.3 to 1.9 years delay in ATTRwt amyloidosis.

CONCLUSION

These findings suggest that orthopedic surgeons may play a role in the early diagnosis of and treatment referrals for ATTR amyloidosis. Detection of MSK manifestations may enable earlier diagnosis and administration of effective treatments before disease progression occurs.

Cardiac Amyloidosis Imaging, Part 3: Interpretation, Diagnosis, and Treatment

Cardiac amyloidosis was thought to be rare, undiagnosable, and incurable. However, recently it has been discovered to be common, diagnosable, and treatable. This knowledge has led to a resurgence in nuclear imaging with ^99mTc-pyrophosphate-a scan once believed to be extinct-to identify cardiac amyloidosis, particularly in patients with heart failure but preserved ejection fraction. The renewed interest in ^99mTc-pyrophosphate imaging has compelled technologists and physicians to reacquaint themselves with the procedure. Although ^99mTc-pyrophosphate imaging is relatively simple, interpretation and diagnostic accuracy require an in-depth knowledge of amyloidosis etiology, clinical manifestations, disease progression, and treatment. Diagnosing cardiac amyloidosis is complicated because typical signs and symptoms are nonspecific and usually attributed to other cardiac disorders. In addition, physicians must be able to differentiate between monoclonal immunoglobulin light-chain amyloidosis (AL) and transthyretin amyloidosis (ATTR). Several clinical and noninvasive diagnostic imaging (echocardiography and cardiac MRI) red flags have been identified that suggest a patient may have cardiac amyloidosis. The intent of these red flags is to raise physician suspicion of cardiac amyloidosis and guide a series of steps (a diagnostic algorithm) for narrowing down and diagnosing the specific amyloid type. One element in the diagnostic algorithm is to identify monoclonal proteins indicative of AL. Monoclonal proteins are detected by serum or urine immunofixation electrophoresis and serum free light-chain assay. Another element is identifying and grading cardiac amyloid deposition using ^99mTc-pyrophosphate imaging. When monoclonal proteins are present and the ^99mTc-pyrophosphate scan is positive, the patient should be further evaluated for cardiac AL. The absence of monoclonal proteins and a positive ^99mTc-pyrophosphate scan is diagnostic for cardiac ATTR. Patients with cardiac ATTR need to undergo genetic testing to differentiate between wild-type ATTR and variant ATTR. This article is the third in a 3-part series in this issue of the Journal of Nuclear Medicine Technology Part 1 reviewed amyloidosis etiology and outlined ^99mTc-pyrophosphate study acquisition. Part 2 described ^99mTc-pyrophosphate image quantification and protocol technical considerations. This article discusses scan interpretation along with cardiac amyloidosis diagnosis and treatment.

The clusterin connectome: Emerging players in chondrocyte biology and putative exploratory biomarkers of osteoarthritis

Introduction

Clusterin is amoonlighting protein that hasmany functions. It is amultifunctional Q6 holdase chaperone glycoprotein that is present intracellularly and extracellularly in almost all bodily fluids. Clusterin is involved in lipid transport, cell differentiation, regulation of apoptosis, and clearance of cellular debris, and plays a protective role in ensuring cellular survival. However, the possible involvement of clusterin in arthritic disease remains unclear. Given the significant potential of clusterin as a biomarker of osteoarthritis (OA), a more detailed analysis of its complex network in an inflammatory environment, specifically in the context of OA, is required. Based on the molecular network of clusterin, this study aimed to identify interacting partners that could be developed into biomarker panels for OA.

Methods

The STRING database and Cytoscape were used to map and visualize the clusterin connectome. The Qiagen Ingenuity Pathway Analysis (IPA) software was used to analyze and study clusterinassociated signaling networks in OA. We also analyzed transcription factors known to modulate clusterin expression, which may be altered in OA.

Results

The top hits in the clusterin network were intracellular chaperones, aggregate-forming proteins, apoptosis regulators and complement proteins. Using a text-mining approach in Cytoscape, we identified additional interacting partners, including serum proteins, apolipoproteins, and heat shock proteins.

Discussion

Based on known interactions with proteins, we predicted potential novel components of the clusterin connectome in OA, including selenoprotein R, semaphorins, and meprins, which may be important for designing new prognostic or diagnostic biomarker panels.

Cardiac Amyloidosis

Amyloidosis is a pathologic and clinical condition resulting from the accumulation of insoluble aggregates of misfolded proteins in tissues. Extracellular deposition of amyloid fibrils in the myocardium leads to cardiac amyloidosis, which is often overlooked as a cause of diastolic heart failure. Although cardiac amyloidosis was previously believed to have a poor prognosis, recent advances in diagnosis and treatment have emphasized the importance of early recognition and changed management of this condition. This article provides an overview of cardiac amyloidosis and summarizes current screening, diagnosis, evaluation, and treatment options.

Prevalence of Orthopedic Manifestations in Patients With Cardiac Amyloidosis With a Focus on Shoulder Pathologies

Transthyretin cardiac amyloidosis (ATTR-CA) is a restrictive cardiomyopathy that has been associated with multiple orthopedic pathologies years before it manifests in the heart. There have been no studies on the prevalence of a wide range of shoulder pathologies in patients with cardiac amyloidosis (CA). Due to the preferential deposition of transthyretin in the soft tissues and joints, we predicted a greater prevalence of shoulder pathologies and other orthopedic manifestations in patients with ATTR-CA. This single-center, retrospective, case-control study, analyzed 1,310 patients with CA, 830 with ATTR-CA, and 480 with light-chain CA (AL-CA) from a dedicated CA REDcap database. Odds ratios comparing patients with CA to the age-matched published estimate of over 300 million patients in the general population were determined for shoulder, hip, and knee arthroplasty. Years between a patient's first shoulder pathology (i.e., shoulder arthroplasty) and the year of their diagnosis with CA were determined using data from patients with a known date of surgery. Overall, patients with ATTR-CA compared with patients with AL-CA presented more frequently with shoulder pathologies (p <0.001) and at least 1 orthopedic manifestation (p <0.001). The odds of patients with ATTR-CA and AL-CA aged 60 years or older who underwent shoulder arthroplasty was 6.05 times greater (95% confidence interval 4.26 to 8.60) and 1.63 times greater (95% confidence interval 0.67 to 3.94), respectively, compared with age-matched controls. Shoulder pathologies and concomitant orthopedic pathologies are common in patients with ATTR-CA and may help identify patients with CA earlier in their disease progression for earlier intervention and treatment.

Ultrasound Measurement of Femoral Cartilage Thickness in Patients with Familial Mediterranean Fever and its Relation to Amyloidosis and Other Disease Characteristics

Objectives

This study aimed to determine femoral cartilage thickness (FCT) in patients with familial Mediterranean fever (FMF) and healthy individuals and to assess the relationship of FCT with the development of amyloidosis and clinical features.

Methods

Patients diagnosed with FMF according to the Tel-Hashomer criteria and healthy controls were included in the study. FCT of both knees was measured with a 7-12 MHz linear probe in maximum knee flexion. Three midpoint measurements were obtained from each knee: Lateral femoral condyle (LFC), intercondylar area (ICA), and medial femoral condyle (MFC). The patients' clinic characteristics include disease duration, medications, comorbid conditions, amyloidosis, chronic renal failure (CRF), FMF gene mutation, arthritis, sacroiliitis, PRAS score, and Physical Activity Questionnaire Short Form score were recorded.

Results

A total of 46 patients with FMF (36 women) and 20 age-sex-body mass index-matched controls (14 women) were enrolled in this study. The patients and controls' mean age were 37±12.9 and 37.5±8.6 years, respectively. Amyloidosis occurred in 7 patients (15.2%), CRF in 3 (6.5%), and knee arthritis in 8 (17%). Disease activity was mild in 55.8%, moderate in 20.9%, and severe in 23.23% of the patients. The mean FCT in millimeter values in the FMF and control groups was as follows: On the right side, LFC 1.9±0.5 and 2±0.52, ICA 2.2±0.77 and 2.25±0.97, and MFC 2±0.47 and 2.25±0.72; on the left side, LFC 1.9±0.4 and 2.05±0.55, ICA 2.25±0.87 and 2.25±0.87, and MFC 1.85±0.5 and 2.25±0.6. Patients with FMF had decreased cartilage thickness at the lateral condyle of both knees (p<0.05) and medial condyle of the left knee (p<0.05) compared with controls. FCT measurements were similar in patients with or without arthritis, amyloidosis, and CRF (p>0.05). FCT scores were not different among the disease activity groups (p>0.05).

Conclusion

These findings suggest that patients with FMF have decreased FCT compared with controls, and there is no significant relationship between the FCT and amyloidosis and disease activity.

Transthyretin Cardiac Amyloidosis: A Cardio-Orthopedic Disease

Orthopaedic manifestations of wild-type transthyretin amyloidosis are frequent and characteristic, including idiopathic bilateral carpal tunnel syndrome, idiopathic lumbar canal stenosis, atraumatic rupture of the brachial biceps tendon, and, more rarely, finger disease and rotator cuff. These manifestations often coexisting in the same patient, frequently male and aged, steadily precede cardiac involvement inducing a rapidly progressive heart failure with preserved ejection fraction. Although transthyretin cardiac amyloidosis remains a cardiac relevant disease, these extracardiac localisation may increase diagnostic suspicion and allow for early diagnosis assuming the role of useful diagnostic red flags, especially in light of new therapeutic opportunities that can slow or stop the progression of the disease. For the cardiologist, the recognition of these extracardiac red flags is of considerable importance to reinforce an otherwise less emerging diagnostic suspicion. For orthopedists and rheumatologists, the presence in an old patient with or without clinical manifestations of cardiovascular disease, of an unexpected and inexplicable constellation of musculoskeletal symptoms, can represent a fundamental moment for an early diagnosis and treatment is improving a patient's outcome.

Trends in diagnosis, referral, red flag onset, patient profiles and natural outcome of de novo cardiac amyloidosis and their multidisciplinary implications

BACKGROUND

Cardiac amyloidosis (CA) is often overlooked or misdiagnosed. Effects of growing disease awareness, diagnostic ameliorations and novel treatment options on CA diagnosis and management are scarcely reported.

OBJECTIVE

To report trends in diagnosis, referral routes, clinical presentation, early onset diagnostic red flags and outcome in de novo CA subjects.

METHODS

An unselected cohort of 139 de novo CA patients over an 8-year period in a tertiary referral hospital was recruited.

RESULTS

Transthyretin (ATTR, 82%, n = 114) was the most common CA form; Light-chain (AL, 15%, n = 21) and secondary (AA, 3%, n = 4) are less prevalent. Increased awareness over time led to a marked ATTR diagnostic surge, steep non-invasive diagnostic approach increment and increased nuclear medicine and external cardiologist referrals (all p < 0.001). A total of 41% (n = 57/139) of patients were referred by non-cardiology specialist disciplines. Specific referral to rule out CA (24-36%) and diagnostic time lag from symptom onset (9 ± 12 to 8 ± 14 months), however, did not improve (all p > 0.050). Multiple early red flag events preceded CA diagnose several years in ATTR: Left ventricular hypertrophy (LVH, 60%, 4.9 ± 4.3 y), heart failure (54%, 2.5 ± 3.5 y), atrial fibrillation (47%, 5.9 ± 6.7 y), bilateral carpal tunnel syndrome (43%, 9.5 ± 5.7 y) and spinal stenosis (40%, 7.4 ± 6.5 y). LVH ≥ 12 mm was absent in 11% ATTR (n = 13/114) and 5% AL (n = 1/21) patients. Hypertension was common in both ATTR (n = 70/114, 62%) and AL (n = 10/21, 48%). 56% (n = 78/139) of CA presented with heart failure. Cumulative 1 and 5-year mortality of 10%/66%, 40%/52% and 75%/75% for ATTR, AL, and AA, respectively, remains high.

CONCLUSIONS

Although CA diagnostic uptake and referral improve, specialist-specific disease and diagnostic red flag ignorance result in non-timely diagnosis and unfavourable outcome.

Clinical relevance of amyloid in prostate samples: a report on 40 patients

OBJECTIVE

To describe the clinical findings in patients with incidental prostatic amyloidosis.

PATIENTS AND METHODS

Retrospective search in the database of the Department of Pathology, Hospital de Bellvitge, for prostate specimens with amyloid. Congo red and immunohistochemical staining of the sections. Review of the patients' clinical charts for symptoms attributable to systemic amyloidosis.

RESULTS

Amyloid deposition in the prostate was identified and reported in 40 patients between 2001 and 2022. Median age was 76.5 years (range 62-90). Prostate cancer was diagnosed in 25 patients. Only 4 patients had a previous diagnosis of amyloidosis. In the remaining 36 the prostate sample (31 needle biopsies, two transurethral resections (TUR), two simple prostatectomies, one radical cystectomy for bladder cancer) provided the initial diagnosis. Amyloid deposits were mainly located in the wall of small vessels and rarely in the prostatic stroma. Immunohistochemistry was available in 32 cases, 26 of which were positive for TTR. All patients showed at least one symptom indicative of systemic amyloidosis, the most frequent being hearing loss (55%), carpal tunnel syndrome (42,5%) or other osteoarticular symptoms (tendinopathies, osteoarthritis), cataracts (37.5%), and cardiac symptoms (32.5%), among others.

CONCLUSION

The prostate is a target tissue for amyloid deposition. The incidental finding of amyloid in prostate corresponds, in the majority of cases, to previously undiagnosed systemic TTR amyloidosis in patients lacking signs of heart involvement but having mainly osteoarticular symptoms, hearing and visual impairment.

Risk of Amyloidosis and Heart Failure Among Patients Undergoing Surgery for Trigger Digit or Carpal Tunnel Syndrome: A Nationwide Cohort Study With Implications for Screening

PURPOSE

Tenosynovial biopsy during carpal tunnel release (CTR) leads to an earlier diagnosis of amyloidosis. Surgery for trigger digit-trigger release (TR)-may provide a similar opportunity. We sought to characterize the risk of amyloidosis diagnosis after TR and/or CTR.

METHODS

We conducted a retrospective cohort study of adults without diagnosed amyloidosis undergoing TR and/or CTR in the Veterans Health Administration from 1999 to 2019, including matched controls. We used competing-risks methodology to estimate the cumulative incidence and adjusted subdistribution hazard ratios (sHRs) of amyloidosis, heart failure, and death after TR and/or CTR.

RESULTS

Among the 126,788 patients undergoing TR and/or CTR, amyloidosis was diagnosed in 52 of 26,757 patients undergoing TR alone at a median of 4.7 years after surgery (10-year cumulative incidence: 0.26%, 95% CI: 0.18% to 0.34%), 396 of 91,384 patients undergoing CTR alone at a median of 5.1 years after surgery (10-year cumulative incidence: 0.60%, 95% CI: 0.53% to 0.67%), 50 of 8,647 patients undergoing both TR and CTR at a median of 3.1 years after surgery (10-year cumulative incidence: 0.80%, 95% CI: 0.54% to 1.1%), and 54 of 113,452 controls at a median of 5.0 years after the index date (10-year cumulative incidence 0.053%, 95% CI: 0.037% to 0.070%). In the adjusted analysis, patients who underwent TR and/or CTR had a higher risk of amyloidosis (TR: sHR_adj 4.80, 95% CI: 3.33-6.92; CTR: sHR_adj 10.2, 95% CI: 7.74-13.6; TR and CTR: sHR_adj 14.9, 95% CI: 9.87-22.5) and heart failure (TR: sHR_adj 1.91, 95% CI: 1.83-1.99; CTR: sHR_adj 2.02, 95% CI: 1.97-2.07; TR and CTR: sHR_adj 2.18, 95% CI: 2.04-2.33) but not death compared with the controls. Among the patients who underwent TR, age, Black race, prior CTR, heart failure, and the number of digits released were independent risk factors for amyloidosis.

CONCLUSIONS

Patients undergoing TR and/or CTR are at increased risk of incident amyloidosis and heart failure compared to controls.

TYPE OF STUDY/LEVEL OF EVIDENCE

Prognostic II.

Prevalence and Subtypes of Tenosynovial Amyloid in Patients Undergoing Carpal Tunnel Release

PURPOSE

The purpose of this study was to determine the prevalence and subtypes of amyloid in tenosynovial biopsies of patients undergoing carpal tunnel release (CTR).

METHODS

A retrospective review was performed involving patients who underwent CTR from June 2020 to July 2021. Prior to this period, a protocol had been established to obtain routine intraoperative tenosynovial biopsies. Tenosynovium was preserved in formalin and stained with Congo red for amyloid. Positive specimens were sent to an external laboratory for confirmation and subtyping by mass spectrometry. Men 50 years or older and women 60 or older were included for analysis. Acute, traumatic, and revision cases were excluded.

RESULTS

Of 185 patients who underwent CTR with tenosynovial biopsy, 54 (29%) demonstrated positive Congo red stain, confirmed by the external laboratory. A subtype analysis revealed wild-type transthyretin (TTR) in 44 patients (80%), mixed wild-type TTR with κ light chains in 1 patient, and hereditary TTR in 1 patient. Patients with positive specimens were significantly older than those who tested negative (77 vs 68 years, respectively), and positivity increased by decade for both sexes. Male sex, atrial fibrillation, and spinal stenosis were significantly more prevalent among positive cases. There were no complications from the biopsies.

CONCLUSIONS

We confirmed evidence of amyloidosis in the tenosynovium of 29% of men 50 years or older and women 60 or older who underwent CTR. The majority demonstrated wild-type TTR. As these patients are at risk of developing cardiomyopathy, there is an opportunity for early detection, monitoring, and interventions known to improve outcomes. Considering the low cost of Congo red staining and the potential value of subtyping with regard to treatment of cardiomyopathy, our findings support routine tenosynovial biopsy during CTR in patients who meet the age criteria.

TYPE OF STUDY/LEVEL OF EVIDENCE

Differential diagnosis or symptom prevalence study II.

Common Factors of Alzheimer's Disease and Rheumatoid Arthritis-Pathomechanism and Treatment

The accumulation of amyloid plaques, or misfolded fragments of proteins, leads to the development of a condition known as amyloidosis, which is clinically recognized as a systemic disease. Amyloidosis plays a special role in the pathogenesis of neurodegenerative diseases such as Alzheimer's disease (AD), Parkinson's disease, and rheumatoid arthritis (RA). The occurrence of amyloidosis correlates with the aging process of the organism, and since nowadays, old age is determined by the comfort of functioning and the elimination of unpleasant disease symptoms in the elderly, exposure to this subject is justified. In Alzheimer's disease, amyloid plaques negatively affect glutaminergic and cholinergic transmission and loss of sympathetic protein, while in RA, amyloids stimulated by the activity of the immune system affect the degradation of the osteoarticular bond. The following monograph draws attention to the over-reactivity of the immune system in AD and RA, describes the functionality of the blood-brain barrier as an intermediary medium between RA and AD, and indicates the direction of research to date, focusing on determining the relationship and the cause-effect link between these disorders. The paper presents possible directions for the treatment of amyloidosis, with particular emphasis on innovative therapies.