Hereditary Transthyretin AmyloidosisLOCUSNCT06414746
Hereditary Transthyretin Amyloidosis Polyneuropathy in Patients With Carpal Tunnel Syndrome in Russia
An observational study of Hereditary Transthyretin Amyloidosis and Carpal Tunnel Syndrome, run by AstraZeneca at 13 sites in Russia.
Trial summary
This is a multicenter observational study consisting of retrospective and prospective phases. The retrospective phase will entail secondary data collection from electronic or paper medical records of patients who underwent surgery for CTS to assess their probability of having ATTR PN. Read more about this study
- Who is it for?
- Ages 18 years and older
- Conditions the study is for
- Hereditary Transthyretin Amyloidosis, Carpal Tunnel Syndrome, Polyneuropathy
- How many people
- 721 participants
- Where
- 13 sitesRussia
- Study dates
- 29 Dec 2023to 12 Jun 2025
- Phase
- Observational
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 18 years and older
- All sexes
- No healthy volunteers
- Adult, Older adult
Study population: This multicenter observational study will retrospectively include 1300 consecutive adult patients diagnosed with CTS and having bilateral involvement in Russia from the earliest date of diagnosis to a later one within the specified time period who are observed and monitored at 20 participating sites, including approximately ~800 patients with CTS and high suspicion of having ATTR PN who will be enrolled in the prospective phase.
Who may be able to join
- for the retrospective phase are:
- Patients with the established diagnosis of CTS.
- Bilateral involvement of carpal tunnel established between the 1st January 2021 and the 31st December 2024 (both patients who underwent CTS surgical intervention and without it are enrolled).
- Age ≥ 18 years at the time of CTS diagnosis.
- Provided written informed consent for the prospective phase of the study (including molecular genetic testing).
- Presence of ≥1 of the following features (red flags):
Show all 9Show fewer
- CIDP or polyneuropathy of unknown etiology in the family history; b. Spinal canal stenosis of the lumbar region; c. Autonomic dysfunction, defined by the presence of ≥1 of the following symptoms - i. Gastrointestinal complaints (constipation, chronic diarrhea, or both); ii. Erectile dysfunction; iii. Orthostatic hypotension; d. Gait disorders; e. Sweating disorders, anhidrosis. f. Paresthesia and burning of the skin of the distal extremities g. Distal symmetrical paresis h. Hypotrophy and hypotension of limb muscles, areflexia i. Biceps tendon rupture j. Aortic valve stenosis k. Diagnosis of HFpEF
- Unexplained weight loss ≥5 kilos at any timepoint since the onset of symptoms of CTS; m. Left ventricular hypertrophy (based on electro- or echocardiographic criteria documented in the patient's medical record); n. Heart rhythm disorders; o. Renal abnormalities, defined by ≥1 of the following features - i. Documented diagnosis of chronic kidney disease (CKD); ii. Decreased estimated glomerular filtration rate (eGFR <60 mL/min/1.73m2); iii. Increased serum creatinine (SCr) above reference range of the local laboratory; iv. Albuminuria (≥30 mg/g of creatinine or ≥30 mg/24h); v. Proteinuria (according to urinalysis results); p. Ophthalmology disorder defined by ≥1 of the following features - i. Vitreous body inclusions (opacification); ii. Glaucoma; iii. Pupillary disorders; iv. Vitrectomy
- Absence of previously established ATTR PN diagnosis (ICD-10 code Е85.1, "Neuropathic hereditary familial amyloidosis").
Who cannot join
- Participation in any interventional trial within the period since identification of bilateral involvement of carpal tunnel until the end of current study.
- The following criteria apply for non-inclusion of patients into the prospective part of the study:
- Previously performed TTR genetic testing;
- Verified B12 deficiency;
- History of alcohol abuse according to the patient's medical record.
Trial locations and contacts
13 sites in 1 country.
13 sites in 1 country
Russia13 sites
Research Site
Arkhangelsk
Research Site
Barnaul
Research Site
Chelyabinsk
Research Site
Irkutsk
Research Site
Kazan'
Research Site
Krasnodar
Research Site
Moscow
Research Site
Nizhny Novgorod
Research Site
Rostov-on-Don
Research Site
Saint Petersburg
Research Site
Samara
Research Site
Ufa
Research Site
Yekaterinburg
About this study
Official title: A Multicenter Observational Retrospective-prospective Study of Prevalence, Clinical Characteristics of Hereditary Transthyretin Amyloidosis Polyneuropathy in Russian Patients Undergoing Surgery for CTS in Real Clinical Practice
This is a multicenter observational study consisting of retrospective and prospective phases. The retrospective phase will entail secondary data collection from electronic or paper medical records of patients who underwent surgery for CTS to assess their probability of having ATTR PN.
Read the detailed description
ATTR PN is a genotypically, phenotypically and geographically variable disease with a poor prognosis, albeit available disease-modifying drugs can change the disease trajectory. Thus country-specific epidemiologic data collection and identification of early stage PN, including previously misdiagnosed patients, is crucial to improve outcomes and quality of life. However, no observational studies on the epidemiology of ATTR PN in the whole Russian population, or in patients with CTS, have been performed.
Therefore, there is a need to conduct a large-scale observational study to determine the prevalence of ATTR PN in Russia, obtain information on patients' clinical characteristics, and determine their medical needs.
The approaches to diagnosis of ATTR PN in Russia over the past few years have been characterized by the use of heterogenous methods, partially explained by the lack of availability of molecular genetic testing, which is essential to diagnose the presence of pathogenic mutation in patients with hereditary ATTR PN. Thus, recent introduction of such tests into routine clinical practice may allow to assess reliable epidemiologic data including estimation of true ATTR PN prevalence among patients with CTS, which can often be the first manifestation of the disease. Earlier recognition, in turn, may lead to timely treatment initiation and change in the prognostic outlook of ATTR PN patients.
In order to assess the prevalence of ATTR PN in patients undergoing surgery for CTS in Russia this study will retrospectively include patients with the diagnosis of CTS undergoing surgery between the 1st January 2021 and the 1st September 2024. Suspicion of ATTR PN will be assessed in each case, and diagnostic tests (comprehensive neurological examination including nerve conduction study (NCS) combined with molecular genetic testing) to confirm or exclude the disease will be conducted prospectively in eligible patients. In addition to that, clinical features, concomitant manifestations, and diagnosed genotypes will be analyzed to examine characteristic ATTR PN patient profiles in the Russian Federation.
- Keywords
- ATTR PN, CTS, PN, carpal tunnel syndrome, polyneuropathy, amyloidosis
- Medical subject headings
- Amyloidosis, Hereditary, Transthyretin-Related, Carpal Tunnel Syndrome, Polyneuropathies, Amyloidosis
What is being measured
The primary outcome is the main question the study is designed to answer.
To define the prevalence of ATTR PN in patients diagnosed with CTS and having bilateral involvement in routine clinical practice in the Russian Federation.
In order to achieve primary objective, the proportion of patients with confirmed diagnosis of ATTR PN (presence of TTR gene mutation according to the results of molecular genetic testing and clinical symptoms and/or signs of polyneuropathy) among those diagnosed with CTS and having bilateral involvement will be calculated.
Measured: Up to 12 months
Secondary outcomes (68)
To assess general demographic characteristics of patients with ATTR PN in Russia - Mean age (years) at the onset of CTS symptoms
Measured: up to 12 months
To assess general demographic characteristics of patients with ATTR PN in Russia: Mean age (years) at the onset of polyneuropathy symptoms
Measured: up to 12 months
to assess general demographic characteristics of patients with ATTR PN in Russia: Proportion of patients with late (>50 years) diagnosis of ATTR PN
Measured: up to 12 months
to assess general demographic characteristics of patients with ATTR PN in Russia: Mean age (years) at the time of CTS surgery
Measured: up to 12 months
to assess general demographic and clinical characteristics of patients with ATTR PN in Russia - Number and proportion of patients with specific characteristics of the first and repeat CTS surgery
- Left hand;
- Right hand;
- Both hands;
Measured: up to 12 months
to assess general demographic and clinical characteristics of patients with ATTR PN in Russia: Proportion of patients with CTS recurrence after surgery
Measured: up to 12 months
to assess general demographic and clinical characteristics of patients with ATTR PN in Russia: Proportion of patients undergoing repeat surgery for CTS after the index operation
Measured: up to 12 months
to assess general demographic and clinical characteristics of patients with ATTR PN in Russia: Proportion of patients with PN progression after surgery
Measured: up to 12 months
to assess general demographic and clinical characteristics of patients with ATTR PN in Russia - Proportion of patients with different number of red flags:
- 1 red flag;
- 2 red flags;
- 3 red flags;
- 4-5 red flags;
- 6-10 red flags;
- >10 red flags;
Measured: up to 12 months
to assess general demographic and clinical characteristics of patients with ATTR PN in Russia: Mean age (years) at ATTR PN diagnosis
Measured: up to 12 months
to assess general demographic and clinical characteristics of patients with ATTR PN in Russia: Proportion of women and men
Measured: up to 12 months
to assess general demographic and clinical characteristics of patients with ATTR PN in Russia - Mean body mass index (BMI) and proportion of patients with different BMI dimensions at the time of CTS diagnosis and at Visit 1:
- Underweight (BMI <18.5 kg/m2);
- Normal weight (BMI ≥18.5 and <25 kg/m2);
- Overweight (BMI ≥25 and <30 kg/m2);
- Obesity (BMI ≥30 kg/m2)
Measured: up to 12 months
to assess general demographic and clinical characteristics of patients with ATTR PN in Russia: Proportion of patients with a history of unexplained weight loss (≥5 kg) at any point since CTS diagnosis
Measured: up to 12 months
to assess general demographic and clinical characteristics of patients with ATTR PN in Russia: Mean and median time from CTS symptom onset (months) to ATTR PN diagnosis
Measured: up to 12 months
To assess general demographic and clinical characteristics of patients with ATTR PN in Russia: Median number of physicians seen since symptom onset before the correct ATTR PN diagnosis
Measured: up to 12 months
To assess general demographic and clinical characteristics of patients with ATTR PN in Russia: Median number of hospitalizations for PN before the correct ATTR PN diagnosis
Measured: up to 12 months
to assess general demographic and clinical characteristics of patients with ATTR PN in Russia - Number and proportion of patients with previously established incorrect diagnosis according to medical records, specifically with:
- CIDP;
- Lumbar/sacral radiculopathy;
- Lumbar canal stenosis;
- Paraproteinaemic peripheral neuropathy;
- Chronic progressive sensory/sensorimotor axonal idiopathic PN;
- AL amyloidosis;
- Fibromyalgia;
- Other (specify)
Measured: up to 12 months
To describe data on the presence of cardiovascular, neurological and other comorbidities in Russian patients with ATTR PN: Proportion of patients with family history of neuropathic disease
Measured: up to 12 months
To describe data on the presence of cardiovascular, neurological and other comorbidities in Russian patients with ATTR PN: Proportion of patients with specific peripheral neurological manifestations:
- Neuropathic pain (allodynia, hyperalgesia);
- Progressive sensory disturbances (loss of temperature, pain, other sensation);
- Paresthesia, dysesthesia;
- Progressive motor disturbances;
- Walking difficulty, gait disorder;
- Balance disorder
Measured: up to 12 months
To describe data on the presence of cardiovascular, neurological and other comorbidities in Russian patients with ATTR PN: Proportion of patients with specific Polyneuropathy Disability (PND) classes:
- 0;
- I;
- II;
- IIIA;
- IIIB;
- IV;
Measured: up to 12 months
To describe data on the presence of cardiovascular, neurological and other comorbidities in Russian patients with ATTR PN - Proportion of patients with specific distribution of polyneuropathy symptoms:
- Upper-limb;
- Lower-limb;
- Both upper-limb and lower-limb
Measured: up to 12 months
To describe data on the presence of cardiovascular, neurological and other comorbidities in Russian patients with ATTR PN - Number of patients with autonomic neurological manifestations, including specifically:
- Orthostatic hypotension;
- Syncope;
- Gastrointestinal motility disorders - i. Constipation; ii. Early satiety; iii. Diarrhea; iv. Nausea, vomiting;
- Erectile dysfunction;
- Neurogenic bladder;
- Recurrent urinary infections;
- Anhidrosis;
Measured: up to 12 months
To describe data on the presence of cardiovascular, neurological and other comorbidities- Number and proportion of patients taking specific groups of cardiovascular medications at the time of CTS diagnosis and at the time of prospective visit:
- Left ventricular hypertrophy;
- Left bundle branch block;
- Atrioventricular block;
- Heart failure with preserved ejection fraction;
- Elevated serum N-terminal-proB-type natriuretic peptide (NT-proBNP) concentration;
- Cardiac valve stenosis;
- Cardiac valve regurgitation;
- Tachyarrhythmia;
- Other (specify);
- None;
Measured: up to 12 months
Number of patients taking specific groups of cardiovascular medications at the time of CTS surgery and at the time of prospective visit:
- Angiotensin converting enzyme inhibitor (ACEI) (specify);
- Angiotensin receptor blocker (ARB) (specify);
- Angiotensin receptor and neprilysin inhibitor (ARNI);
- Sodium-glucose transporter type 2 inhibitor (SGLT2i) (specify);
- Mineralocorticoid receptor antagonist (MRA) (specify);
- Beta-blocker (specify);
- Diuretic (specify);
- Other cardiovascular (CV) medications (specify);
- Other (specify);
Measured: up to 12 months
To describe data on the presence of cardiovascular, neurological and other comorbidities in Russian patients with ATTR PN - Number of patients with concomitant ophthalmologic manifestations, including specifically
- Vitreous body inclusions (opacification);
- Glaucoma;
- Abnormal conjunctival vessels;
- Papillary abnormalities;
- Dry eye;
- Other (specify);
Measured: up to 12 months
To describe data on the presence of cardiovascular, neurological and other comorbidities in Russian patients with ATTR PN - Number of patients with concomitant musculoskeletal manifestations, including specifically:
- Spinal stenosis;
- Osteoarthritis, including hip and knee arthroplasty;
- Trigger finger;
- Charcot's joints;
- Biceps tendon rupture;
- Rotator cuff injury;
- Other (specify);
Measured: up to 12 months
Mean and median serum NT-proBNP (pg/ml) concentration
Measured: up to 12 months
Proportion of patients with laboratory confirmed paraproteinemia
Measured: up to 12 months
Mean and median urine albumin-creatinine ratio (UACR, mg/g of creatinine)
Measured: up to 12 months
Proportion of patients with diagnosed CKD, including specifically
- Stage C1;
- Stage C2;
- Stage C3a;
- Stage C3b;
- Stage C4;
- Stage C5;
Measured: up to 12 months
Number of patients with concomitant renal dysfunction, including specifically
- Elevated SCr level (based on the local laboratory reference range);
- Decreased eGFR (<60 ml/min/1.73m2);
- Presence of albuminuria (≥30 mg/g creatinine (≥30 mg/g of creatinine or ≥30 mg/24h);
- Presence of proteinuria (according to urinalysis results);
- Ultrasound signs of amyloid nephropathy;
Measured: up to 12 months
Number of patients with confirmed length-dependent peripheral sensory-motor neuropathy based on NCS results
Measured: up to 12 months
Mean and median measured peripheral sensory nerve conduction velocities
- Left Medial;
- Left Ulnar;
- Left Sural;
- Right Medial;
- Right Ulnar;
- Right Sural;
Measured: up to 12 months
Number of patients with reduced peripheral sensory nerve conduction velocity at ≥1 site
Measured: up to 12 months
Mean and median measured peripheral motor nerve conduction velocities
- Left Medial;
- Left Ulnar;
- Left Tibial;
- Left Peroneal;
- Right Medial;
- Right Ulnar;
- Right Tibial;
- Right Peroneal;
Measured: up to 12 months
Number of patients with reduced motor sensory nerve conduction velocity at ≥1 site
Measured: up to 12 months
Mean and median measured sensory action potential (SAP) amplitudes
- Left Medial;
- Left Ulnar;
- Left Sural;
- Right Medial;
- Right Ulnar;
- Right Sural
Measured: up to 12 months
Number of patients with reduced/absent SAP amplitude at ≥1 site
Measured: up to 12 months
Mean and median measured distal compound muscle action potential (dCMAP) amplitudes
- Left Medial;
- Left Ulnar;
- Left Tibial;
- Left Peroneal;
- Right Medial;
- Right Ulnar;
- Right Tibial;
- Right Peroneal
Measured: up to 12 months
Mean and median measured proximal compound muscle action potential (pCMAP) amplitudes
- Left Medial;
- Left Ulnar;
- Left Tibial;
- Left Peroneal;
- Right Medial;
- Right Ulnar;
- Right Tibial;
- Right Peroneal
Measured: up to 12 months
Number of patients with reduced/absent dCMAP amplitude at ≥1 site
Measured: up to 12 months
Number of patients with reduced/absent pCMAP amplitude at ≥1 site
Measured: up to 12 months
Proportion of patients with each score by each parameter of neurological examination
Measured: up to 12 months
Number of patients in the specific categories of the modified Rankin scale
- Score 1 (no significant disability);
- Score 2 (slight disability);
- Score 3 (moderate disability);
- Score 4 (moderately severe disability);
- Score 5 (severe disability);
Measured: up to 12 months
Proportion of patients with specific number of points according to Inflammatory Neuropathy Cause and Treatment (INCAT) upper extremity scale
- 0 points;
- 1 point;
- 2 points;
- 3 points;
- 4 points;
- 5 points
Measured: up to 12 months
Median number of points according to INCAT upper extremity scale
Measured: up to 12 months
Proportion of patients with specific number of points according to INCAT lower extremity scale
- 0 points;
- 1 point;
- 2 points;
- 3 points;
- 4 points;
- 5 points
Measured: up to 12 months
Median number of points according to INCAT lower extremity scale
Measured: up to 12 months
Mean and median number of points according to combined clinical and electrophysiological score
Measured: up to 12 months
To describe data on the results of genetic testing for ATTR in CTS patients undergoing surgery:Number and proportion of patients with specific TTR gene mutations
- Val30Met;
- Ile107Val;
- Phe33Leu;
- Ala81Val;
- Ser23Asn;
- Ala25Thr;
- Val32Ala;
- Thr40Asn;
- Gly47Ala;
- Glu54Gln;
- Tyr69Phe;
- Glu92Lys;
- Thr119Met;
- Other
Measured: up to 12 months
to assess general demographic and clinical characteristics of patients with ATTR PN in Russia - Proportion of patients with previously established incorrect diagnosis according to medical records, specifically with:
- CIDP;
- Lumbar/sacral radiculopathy;
- Lumbar canal stenosis;
- Paraproteinaemic peripheral neuropathy;
- Chronic progressive sensory/sensorimotor axonal idiopathic PN;
- AL amyloidosis;
- Fibromyalgia;
- Other (specify);
Measured: up to 12 months
To describe data on the presence of cardiovascular, neurological and other comorbidities in Russian patients with ATTR PN - proportion of patients with autonomic neurological manifestations, including specifically:
manifestations, including specifically:
- Orthostatic hypotension;
- Syncope;
- Gastrointestinal motility disorders - i. Constipation; ii. Early satiety; iii. Diarrhea; iv. Nausea, vomiting;
- Erectile dysfunction;
- Neurogenic bladder;
- Recurrent urinary infections;
- Anhidrosis;
Measured: up to 12 months
To describe data on the presence of cardiovascular, neurological and other comorbidities in Russian patients with ATTR PN - proportion of patients with concomitant cardiac manifestations, including specifically:
- Left ventricular hypertrophy;
- Left bundle branch block;
- Atrioventricular block;
- Heart failure with preserved ejection fraction;
- Elevated serum N-terminal-proB-type natriuretic peptide (NT-proBNP) concentration;
- Cardiac valve stenosis;
- Cardiac valve regurgitation;
- Tachyarrhythmia;
- Other (specify);
- None;
Measured: up to 12 months
proportion of patients taking specific groups of cardiovascular medications at the time of CTS surgery and at the time of prospective visit:
- Angiotensin converting enzyme inhibitor (ACEI) (specify);
- Angiotensin receptor blocker (ARB) (specify);
- Angiotensin receptor and neprilysin inhibitor (ARNI);
- Sodium-glucose transporter type 2 inhibitor (SGLT2i) (specify);
- Mineralocorticoid receptor antagonist (MRA) (specify);
- Beta-blocker (specify);
- Diuretic (specify);
- Other cardiovascular (CV) medications (specify);
- Other (specify);
Measured: up to 12 months
To describe data on the presence of cardiovascular, neurological and other comorbidities in Russian patients with ATTR PN - proportion of patients with concomitant ophthalmologic manifestations, including specifically
- Vitreous body inclusions (opacification);
- Glaucoma;
- Abnormal conjunctival vessels;
- Papillary abnormalities;
- Dry eye;
- Other (specify);
Measured: up to 12 months
To describe data on the presence of cardiovascular, neurological and other comorbidities in Russian patients with ATTR PN - proportion of patients with concomitant musculoskeletal manifestations, including specifically:
- Spinal stenosis;
- Osteoarthritis, including hip and knee arthroplasty;
- Trigger finger;
- Charcot's joints;
- Biceps tendon rupture;
- Rotator cuff injury;
- Other (specify);
Measured: up to 12 months
proportion of patients with concomitant renal dysfunction, including specifically
- Elevated SCr level (based on the local laboratory reference range);
- Decreased eGFR (<60 ml/min/1.73m2);
- Presence of albuminuria (≥30 mg/g creatinine (≥30 mg/g of creatinine or ≥30 mg/24h);
- Presence of proteinuria (according to urinalysis results);
- Ultrasound signs of amyloid nephropathy;
Measured: up to 12 months
proportion of patients with confirmed length-dependent peripheral sensory-motor neuropathy based on NCS results
Measured: up to 12 months
proportion of patients with reduced peripheral sensory nerve conduction velocity at ≥1 site
Measured: up to 12 months
proportion of patients with reduced motor sensory nerve conduction velocity at ≥1 site
Measured: up to 12 months
proportion of patients with reduced/absent SAP amplitude at ≥1 site
Measured: up to 12 months
proportion of patients with reduced/absent dCMAP amplitude at ≥1 site
Measured: up to 12 months
proportion of patients with reduced/absent pCMAP amplitude at ≥1 site
Measured: up to 12 months
proportion of patients in the specific categories of the modified Rankin scale
-a) Score 1 (no significant disability); b) Score 2 (slight disability); c) Score 3 (moderate disability); d) Score 4 (moderately severe disability); e) Score 5 (severe disability
Measured: up to 12 months
To assess general demographic characteristics of patients with ATTR PN in Russia - Mean age (years) at the primary CTS diagnosis
Measured: up to 12 months
To assess general demographic characteristics of patients with ATTR PN in Russia - Mean age (years) at the identification of bilateral involvement
Measured: up to 12 months
To assess general demographic characteristics of patients with ATTR PN in Russia - Mean age (years) at ATTR PN diagnosis
Measured: up to 12 months
To assess general demographic characteristics of patients with ATTR PN in Russia -Proportion of patients underwent CTS surgery (i.e. at least one surgery)
Measured: up to 12 months
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted16 May 2024
- Study start29 Dec 2023
- Primary completion12 Jun 2025
- Study completion12 Jun 2025
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Hereditary Transthyretin AmyloidosisStudies of the same condition, open and under way.
- More trials run by AstraZenecaThe sponsor's other registered studies.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Observational
- Observational model
- Case-control
- Time perspective
- Cross-sectional
- Enrolment
- 721 participants (actual)
Sponsor and investigators
- Lead sponsor
- AstraZeneca
- Sponsor type
- Industry (pharma, biotech, devices)
- Responsible party
- Sponsor
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT06414746
- Sponsor's protocol ID
- D8451R00001
- Acronym
- LOCUS
- Status last verified
- Apr 2026
- First submitted
- 16 Feb 2024
- Last updated
- 4 Jun 2026
- Results posted
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No