Familial amyloidosis: a study of 52 North American-born patients examined during a 30-year period

Effectiveness of patisiran after switching from tafamidis for the treatment of hereditary transthyretin-mediated amyloidosis with polyneuropathy

BACKGROUND AND PURPOSE

Hereditary transthyretin-mediated amyloidosis with polyneuropathy (ATTRv-PN [v for variant]) is a rare, progressive disease associated with multisystemic impairments. This study assessed the real-world outcomes of patients with ATTRv-PN who switched from tafamidis to patisiran, as well as the reasons for the treatment switch.

METHODS

This was a retrospective chart review study at a large expert referral center. Data were extracted from medical charts of patients with ATTRv-PN who switched from tafamidis to patisiran on or before 30 August 2019. Data elements included demographic and clinical characteristics, rationale for switch, and disease measures evaluated from tafamidis initiation through the 12-month patisiran treatment period.

RESULTS

Among the 24 patients with ATTRv-PN included in the study, 50.0% had a V30M variant, and the mean (SD) age was 67.3 (8.0) years. During tafamidis treatment (mean [SD] = 30.1 [17.5] months) before switching to patisiran, patients worsened across multiple polyneuropathy measures, including walking ability, Neuropathy Impairment Score, and autonomic function. Neuropathic disease progression on tafamidis was the principal reason for switching to patisiran. After 12 months on patisiran (mean [SD] = 11.7 [1.4] months), patients experienced attenuated disease progression or improvement in the aforementioned measures of polyneuropathy.

CONCLUSIONS

Switching from tafamidis to patisiran attenuated the rate of functional decline, and most patients experienced stabilization or improvement of at least one polyneuropathy measure within 12 months of patisiran treatment. Timely switch from tafamidis to patisiran can be beneficial to avoid rapid disease progression in patients with ATTRv-PN.

Predictors of developing renal dysfunction following diagnosis of transthyretin cardiac amyloidosis

BACKGROUND

In patients with transthyretin cardiac amyloidosis (ATTR-CA), renal dysfunction is a poor prognostic indicator. Limited data are available on variables that portend worsening renal function (wRF) among ATTR-CA patients.

OBJECTIVES

This study assesses which characteristics place patients at higher risk for the development of wRF (defined as a drop of ≥10% in glomerular filtration rate [GFR]) within the first year following diagnosis of ATTR-CA.

METHODS

We included patients with ATTR-CA (n = 134) evaluated between 2/2016 and 12/2022 and followed for up to 1 year at our amyloid clinic. Patients were stratified into two groups: a group with maintained renal function (mRF) and a group with wRF and compared using appropriate testing. Significant variables in the univariate analysis were included in the multivariable logistic regression model to determine characteristics associated with wRF.

RESULTS

Within a follow-up period of 326 ± 118 days, the median GFR% change measured -6% [-18%, +8]. About 41.8% (n = 56) had wRF, while the remainder had mRF. In addition, in patients with no prior history of chronic kidney disease (CKD), 25.5% developed de novo CKD. On multivariable logistic regression, only New York Heart Association (NYHA) class ≥III (odds ratio [OR]: 3.9, 95% confidence interval [CI]: [1.6-9.3]), history of ischemic heart disease (IHD) (OR: 0.3, 95% CI: [0.1-0.7]), and not receiving SGLT-2i (OR: 0.1, 95% CI: [0.02-0.5]) were significant predictors of wRF.

CONCLUSION

Our study demonstrated that the development of de novo renal dysfunction or wRF is common following the diagnosis of ATTR-CA. Additionally, we identified worse NYHA class and no prior history of IHD as significant predictors associated with developing wRF, while receiving SGLT-2i therapy appeared to be protective in this population.

Impact of Vutrisiran on Quality of Life and Physical Function in Patients with Hereditary Transthyretin-Mediated Amyloidosis with Polyneuropathy

INTRODUCTION

Hereditary transthyretin (ATTRv; v for variant) amyloidosis, also known as hATTR amyloidosis, is a progressive and fatal disease associated with rapid deterioration of physical function and patients' quality of life (QOL). Vutrisiran, a subcutaneously administered RNA interference (RNAi) therapeutic that reduces hepatic production of transthyretin, was assessed in patients with ATTRv amyloidosis with polyneuropathy in the pivotal HELIOS-A study.

METHODS

The phase 3 open-label HELIOS-A study investigated the efficacy and safety of vutrisiran in patients with ATTRv amyloidosis with polyneuropathy, compared with an external placebo group from the APOLLO study of the RNAi therapeutic patisiran. Measures of QOL and physical function were assessed.

RESULTS

At month 18, vutrisiran improved Norfolk Quality of Life-Diabetic Neuropathy (Norfolk QOL-DN) total score (least squares mean difference [LSMD] in change from baseline [CFB]: -21.0; p = 1.84 × 10-10) and Norfolk QOL-DN domain scores, compared with external placebo. This benefit relative to external placebo was evident across all baseline polyneuropathy disability (PND) scores and most pronounced in patients with baseline PND scores I-II. Compared with external placebo, vutrisiran also demonstrated benefit in EuroQoL-Visual Analog Scale (EQ-VAS) score (LSMD in CFB: 13.7; nominal p = 2.21 × 10-7), 10-m walk test (LSMD in CFB: 0.239 m/s; p = 1.21 × 10-7), Rasch-built Overall Disability Score (LSMD in CFB: 8.4; p = 3.54 × 10-15), and modified body mass index (mBMI) (LSMD in CFB: 140.7; p = 4.16 × 10-15) at month 18. Overall, Norfolk QOL-DN, EQ-VAS, and mBMI improved from pretreatment baseline with vutrisiran, whereas all measures worsened from baseline in the external placebo group. At month 18, Karnofsky Performance Status was stable/improved from baseline in 58.2/13.1% with vutrisiran versus 34.7/8.1% with external placebo.

CONCLUSION

Vutrisiran treatment provided significant clinical benefits in multiple measures of QOL and physical function in patients with ATTRv amyloidosis with polyneuropathy. Benefits were most pronounced in patients with earlier-stage disease, highlighting the importance of early diagnosis and treatment.

TRIAL REGISTRATION NUMBER

ClinicalTrials.gov: NCT03759379.

Amyloidosis and the Kidney: An Update

Various types of systemic amyloidosis can wreak havoc on the architecture and functioning of the kidneys. Amyloidosis should be suspected in patients with worsening kidney function, proteinuria, and multisystem involvement, but isolated kidney involvement also is possible. Confirming the amyloidosis type and specific organ dysfunction is of paramount importance to select the appropriately tailored treatment and aim for better survival while avoiding treatment-associated toxicities. Amyloid renal staging in light chain amyloidosis amyloidosis helps inform prognosis and risk for end-stage kidney disease. Biomarker-based staging systems and response assessment guide the therapeutic strategy and allow the timely identification of refractory or relapsing disease so that patients can be switched to salvage therapy. Kidney transplantation is a viable option for selected patients with amyloidosis. Because of the complex nature of the pathophysiology and treatment of amyloidosis, a multidisciplinary team-based approach should be used in the care of these patients.

Efficacy and safety of vutrisiran for patients with hereditary transthyretin-mediated amyloidosis with polyneuropathy: a randomized clinical trial

BACKGROUND

The study objective was to assess the effect of vutrisiran, an RNA interference therapeutic that reduces transthyretin (TTR) production, in patients with hereditary transthyretin (ATTRv) amyloidosis with polyneuropathy.

METHODS

HELIOS-A was a phase 3, global, open-label study comparing the efficacy and safety of vutrisiran with an external placebo group (APOLLO study). Patients were randomized 3:1 to subcutaneous vutrisiran 25 mg every 3 months (Q3M) or intravenous patisiran 0.3 mg/kg every 3 weeks (Q3W) for 18 months.

RESULTS

HELIOS-A enrolled 164 patients (vutrisiran, n = 122; patisiran reference group, n = 42); external placebo, n = 77. Vutrisiran met the primary endpoint of change from baseline in modified Neuropathy Impairment Score +7 (mNIS+7) at 9 months (p = 3.54 × 10^-12), and all secondary efficacy endpoints; significant improvements versus external placebo were observed in Norfolk Quality of Life-Diabetic Neuropathy, 10-meter walk test (both at 9 and 18 months), mNIS+7, modified body-mass index, and Rasch-built Overall Disability Scale (all at 18 months). TTR reduction with vutrisiran Q3M was non-inferior to within-study patisiran Q3W. Most adverse events were mild or moderate in severity, and consistent with ATTRv amyloidosis natural history. There were no drug-related discontinuations or deaths.

CONCLUSIONS

Vutrisiran significantly improved multiple disease-relevant outcomes for ATTRv amyloidosis versus external placebo, with an acceptable safety profile.

CLINICALTRIALS.GOV

NCT03759379.

Amyloidosis of the Heart: A Comprehensive Review

Cardiac amyloidosis is a progressive, infiltrative cardiomyopathy, whose types are based on various infiltrating amyloids, namely, light chains in primary amyloidosis, mutated transthyretin proteins in hereditary amyloidosis, and wild-type transthyretin proteins in senile amyloidosis. While cardiac amyloidosis has a non-specific presentation, the type-specific presentations may provide some clues to the diagnosis. While tissue biopsy remains the gold standard, other newer non-invasive methods can aid in the diagnostic approach for suspected cardiac amyloidosis. Various medications used to treat heart failure may lead to adverse outcomes in patients with cardiac amyloidosis. More research is needed to understand the adequate management and treatment of cardiac amyloidosis.

Patisiran treatment in patients with hereditary transthyretin-mediated amyloidosis with polyneuropathy after liver transplantation

Hereditary transthyretin-mediated (hATTR) amyloidosis, or ATTRv amyloidosis, is a progressive disease, for which liver transplantation (LT) has been a long-standing treatment. However, disease progression continues post-LT. This Phase 3b, open-label trial evaluated efficacy and safety of patisiran in patients with ATTRv amyloidosis with polyneuropathy progression post-LT. Primary endpoint was median transthyretin (TTR) reduction from baseline. Twenty-three patients received patisiran for 12 months alongside immunosuppression regimens. Patisiran elicited a rapid, sustained TTR reduction (median reduction [Months 6 and 12 average], 91.0%; 95% CI: 86.1%-92.3%); improved neuropathy, quality of life, and autonomic symptoms from baseline to Month 12 (mean change [SEM], Neuropathy Impairment Score, -3.7 [2.7]; Norfolk Quality of Life-Diabetic Neuropathy questionnaire, -6.5 [4.9]; least-squares mean [SEM], Composite Autonomic Symptom Score-31, -5.0 [2.6]); and stabilized disability (Rasch-built Overall Disability Scale) and nutritional status (modified body mass index). Adverse events were mild or moderate; five patients experienced ≥1 serious adverse event. Most patients had normal liver function tests. One patient experienced transplant rejection consistent with inadequate immunosuppression, remained on patisiran, and completed the study. In conclusion, patisiran reduced serum TTR, was well tolerated, and improved or stabilized key disease impairment measures in patients with ATTRv amyloidosis with polyneuropathy progression post-LT (www.clinicaltrials.gov NCT03862807).

Kidney involvement in hereditary transthyretin amyloidosis: a cohort study of 103 patients

Background

Hereditary transthyretin amyloidosis (ATTRv) is a disabling and life-threatening disease that primarily affects the nervous system and heart. Its kidney involvement has not been systematically studied, particularly in non-V30M mutations, and is not well known to nephrologists.

Methods

We conducted a retrospective study describing the kidney phenotype of all prevalent patients with ATTR mutations, with neurological or cardiac involvement or presymptomatic carriers, followed up in two university hospitals from the South of France between June 2011 and June 2021.

Results

A total of 103 patients were included, among whom 79 were symptomatic and 24 were presymptomatic carriers. Patients carried 21 different ATTR mutations and 54% carried the V30M mutation. After a mean follow-up of 7.9 ± 25.7 years, 30.4% of the symptomatic patients had developed chronic kidney disease (CKD) and 20.3% had a urinary protein:creatinine ratio ≥0.5 g/g. None of the presymptomatic carriers had CKD or proteinuria. In a multivariate analysis, late onset of symptoms (after 60 years), the V122I mutation and proteinuria were significantly associated with CKD. The median CKD-free survival in symptomatic patients was estimated at 81.0 years (interquartile range 77.1–84.9). It did not differ between V30M and non-V30M patients, but was lower in patients with the V122I mutation. The average age of the onset of CKD was 69.3 ± 13.0 years. In one 38-year-old V30M female who presented a kidney-predominant phenotype, treatment with patisiran resulted in remission of the nephrotic syndrome.

Conclusion

CKD affects almost one-third of patients with symptomatic ATTRv. The role of ATTRv per se in the development of CKD in this population remains to be determined, but some patients may benefit from specific therapies.

Hereditary transthyretin-mediated amyloidosis with polyneuropathy: baseline anthropometric, demographic and disease characteristics of patients from a reference center

BACKGROUND

Hereditary transthyretin-mediated (hATTR) amyloidosis with polyneuropathy is a rare, inherited, multisystem, and often fatal disease caused by a variant in transthyretin (TTR) gene. Baseline characteristics of patients, especially anthropometric data, are scarce in the literature, and they are relevant to define effective treatment strategies.

OBJECTIVE

This study aimed to describe baseline demographic, anthropometric, and disease characteristics in a cohort of patients from a reference center in Brazil.

METHODS

Symptomatic patients not previously included in clinical trials and eligible for treatment were enrolled. Ethnicity, state of residence, age, sex, weight, height, body mass index (BMI), TTR variant, and Polyneuropathy Disability Score (PND) at diagnosis were analyzed.

RESULTS

Among the 108 patients enrolled, 58.33% were male, 60.19% were Caucasian, and 83.33% lived in the Southeast region. Mean age was 51.61 (±16.37) years, mean weight was 65.76 (±15.16) kg, mean height was 168.33 (±10.26) cm, and mean BMI was 23.11 (±4.45) kg/m2. The most prevalent variant was V30M (86.11%). Patients with PND score 0 presenting autonomic neuropathy were 14.81%. Patients with PND score I-II and III-IV were 52.78 and 32.41%, respectively. Mean weight and BMI were significantly lower in patients with sensory-motor manifestations.

CONCLUSIONS

This is the largest cohort of patients in Brazil for whom anthropometric characteristics have been described. Baseline demographic, anthropometric, and disease data indicate that delay in diagnosis of hATTR amyloidosis with polyneuropathy is still a problem and that efforts must be made to expedite diagnosis and maximize opportunities for new disease-modifying treatments.

Variable Presentation of Hereditary Transthyretin-Mediated Amyloidosis at a Single Center

OBJECTIVES

Describe atypical presentations of hereditary transthyretin-mediated (hATTR) amyloidosis with polyneuropathy.

METHODS

Initial symptoms, diagnoses, and follow-up were recorded at the Austin Neuromuscular Center for 12 patients with nonclassical presentation of hATTR amyloidosis.

RESULTS

Common initial symptoms were hand and/or feet sensory manifestations (83%), muscle weakness (58%), and, less frequently, gastrointestinal and orthostatic impairment and carpal tunnel syndrome. Initial diagnoses were polyneuropathy (83%) and/or myopathy (25%). During follow-up, 10 patients (83%) developed cardiac symptoms (dyspnea, 67% and ankle edema, 17%), resulting in revised diagnoses of heart disease. Multisystem involvement raised suspicion of amyloidosis, which was confirmed by biopsy or nuclear scintigraphy, and genetic testing. All patients had polyneuropathy; 8 (67%) had cardiomyopathy-associated transthyretin mutations (V122I or T60A). Time from symptom onset to diagnosis was up to 10 years (median 5 years), during which patients' health deteriorated, although with recognition of disease signs/symptoms the diagnosis of hATTR amyloidosis was made in approximately 2-6 months from presentation at our center.

CONCLUSIONS

Increased awareness of the diverse initial hATTR amyloidosis symptoms could shorten time to diagnosis, enabling earlier treatment and improved patient outcomes.

Experience of patisiran with transthyretin stabilizers in patients with hereditary transthyretin-mediated amyloidosis

Aim: Examine safety and pharmacodynamics of patisiran alone or with concomitant transthyretin stabilizers from the Phase II open-label extension study and safety and efficacy of patisiran in patients with prior transthyretin stabilizer use from the Phase III APOLLO study. Patients & methods: Post hoc analyses in patients with hereditary transthyretin-mediated amyloidosis with polyneuropathy. Results: Patisiran safety was consistent regardless of concomitant or prior transthyretin stabilizers. In the Phase II open-label extension (n = 27), transthyretin reduction was similar over 24 months, regardless of concomitant transthyretin stabilizers. In APOLLO (n = 225), patisiran-treated groups showed stabilization or improvements in neurological function (modified Neuropathy Impairment Score +7) and quality of life (Norfolk Quality of Life-Diabetic Neuropathy questionnaire) at 18 months, regardless of prior transthyretin stabilizers. Conclusion: Patients benefit from patisiran regardless of transthyretin stabilizer use.

Phase 3 Multicenter Study of Revusiran in Patients with Hereditary Transthyretin-Mediated (hATTR) Amyloidosis with Cardiomyopathy (ENDEAVOUR)

Purpose

The Phase 3 ENDEAVOUR study evaluated revusiran, an investigational RNA interference therapeutic targeting hepatic transthyretin (TTR) production, for treating cardiomyopathy caused by hereditary transthyretin-mediated (hATTR) amyloidosis.

Methods

Patients with hATTR amyloidosis with cardiomyopathy were randomized 2:1 to receive subcutaneous daily revusiran 500 mg (n = 140) or placebo (n = 66) for 5 days over a week followed by weekly doses. Co-primary endpoints were 6-min walk test distance and serum TTR reduction.

Results

Revusiran treatment was stopped after a median of 6.71 months; the study Sponsor prematurely discontinued dosing due to an observed mortality imbalance between treatment arms. Eighteen (12.9%) patients on revusiran and 2 (3.0%) on placebo died during the on-treatment period. Most deaths in both treatment arms were adjudicated as cardiovascular due to heart failure (HF), consistent with the natural history of the disease. A post hoc safety investigation of patients treated with revusiran found that, at baseline, a greater proportion of those who died were ≥ 75 years and showed clinical evidence of more advanced HF compared with those who were alive throughout treatment. Revusiran pharmacokinetic exposures and TTR lowering did not show meaningful differences between patients who died and who were alive. Revusiran did not deleteriously affect echocardiographic parameters, cardiac biomarkers, or frequency of cardiovascular and HF hospitalization events.

Conclusions

Causes for the observed mortality imbalance associated with revusiran were thoroughly investigated and no clear causative mechanism could be identified. Although the results suggest similar progression of cardiac parameters in both treatment arms, a role for revusiran cannot be excluded.

Clinical Trial Registration

NCT02319005.

Electronic supplementary material

The online version of this article (10.1007/s10557-019-06919-4) contains supplementary material, which is available to authorized users.

Population Pharmacokinetic-Pharmacodynamic Model of Serum Transthyretin Following Patisiran Administration

Hereditary transthyretin-mediated amyloidosis is an inherited, rapidly progressive, life-threatening disease caused by mutated transthyretin (TTR) protein. Patisiran is a small interfering RNA (siRNA) formulated in a lipid nanoparticle that inhibits hepatic TTR protein synthesis by RNA interference. We have developed an indirect-response pharmacokinetic-pharmacodynamic model relating plasma siRNA (ALN-18328) levels to serum TTR reduction across five clinical studies. A sigmoidal function described this relationship, with estimated Hill coefficient of 0.548, and half maximal inhibitory concentration (IC₅₀), IC₈₀, and IC₉₀ values of 9.45, 118.5, and 520.5 ng/mL, respectively. Following patisiran 0.3 mg/kg every 3 weeks (q3w), steady-state plasma ALN-18328 exposures were between IC₈₀ and IC₉₀, yielding average serum TTR reductions of 80%-90% from baseline. Covariate analysis indicated similar TTR reduction across evaluated intrinsic and extrinsic factors, obviating the need for dose adjustment. Modeling results support the recommended patisiran dosing schedule of 0.3 mg/kg q3w, with a maximum dose of 30 mg for patients weighing ≥100 kg.

Should the Reporting of Bone Marrow Positivity for Amyloid Be Revised? A Critical Assessment Based On 66 Biopsies From a Single Institution

CONTEXT.—

Amyloidoses are rare but heterogeneous disorders for which diagnosis is contingent upon the detection of deposits by Congo red stain and amyloid protein typing determines the treatment options.

OBJECTIVE.—

To address the reporting of bone marrow (BM) involvement by amyloid in relation to the spatial distribution of deposits and to explore whether the location of deposits may have clinical relevance.

DESIGN.—

We examined 66 BM biopsies positive for amyloid with regard to the location and type of amyloid, the percentage and clonality of plasma cells, other organ involvement, and relevant clinical information.

RESULTS.—

In 21 cases, amyloid deposits involved BM stroma, whereas 45 cases were nonstromal. All cases of stromal involvement were typed as AL amyloidosis (or presumed AL), whereas nonstromal involvement was associated with at least 3 types of amyloidosis: AL, ATTR, and AA. The initial diagnosis of amyloidosis was made in a BM specimen in 21 of 66 cases (31.8%). Plasma cells ranged from 1% to 80% (mean, 13.4%; median, 8%; <10% in 44 of 66 specimens [66.6%]) and were monoclonal in 58 of 66 cases (87.8%), and in 54 of 66 cases (81.8%) amyloid deposits were documented in at least one other organ.

CONCLUSIONS.—

This study demonstrates that there is significant heterogeneity in the spatial distribution of amyloid in BM biopsy specimens with medullary, extramedullary, purely vascular, or combined involvement. Whereas stromal deposits were associated exclusively with AL, nonstromal and purely vascular deposits were seen in at least 3 types of systemic amyloidosis (AL, AA, and ATTR). We discuss the reporting of BM biopsy tissue positivity for amyloid deposits.

Patisiran Pharmacokinetics, Pharmacodynamics, and Exposure-Response Analyses in the Phase 3 APOLLO Trial in Patients With Hereditary Transthyretin-Mediated (hATTR) Amyloidosis

Hereditary transthyretin-mediated (hATTR) amyloidosis is an inherited, rapidly progressive, life-threatening disease caused by deposition of abnormal transthyretin protein. Patisiran is an RNA interference therapeutic comprising a novel, small interfering ribonucleic acid (ALN-18328) formulated in a lipid nanoparticle targeted to inhibit hepatic transthyretin protein synthesis. The lipid nanoparticle also contains 2 novel lipid excipients (DLin-MC3-DMA and PEG2000 -C-DMG). Here we report patisiran pharmacokinetics (PK), pharmacodynamics (PD), and exposure-response analyses from the phase 3 APOLLO trial, in which patients with hATTR amyloidosis with polyneuropathy were randomized 2:1 to receive patisiran 0.3 mg/kg or placebo intravenously every 3 weeks over 18 months. In patisiran-treated patients, mean maximum reduction in serum transthyretin level from baseline was 87.8%. Patisiran PK exposure was stable following chronic dosing. There were no meaningful differences in PK exposure, serum transthyretin reduction, and efficacy (change from baseline in modified Neuropathy Impairment Score+7) across all subgroups analyzed (age, sex, race, body weight, genotype status of valine-to-methionine mutation at position 30 [V30M] and non-V30M, prior use of tetramer stabilizers, mild/moderate renal impairment, and mild hepatic impairment). transthyretin reduction and efficacy were similar across the interpatient PK exposure range for ALN-18328. There was no trend in the incidence of adverse events or serious adverse events across the interpatient PK exposure range for all 3 analytes. Incidence of antidrug antibodies was low (3.4%) and transient, with no impact on PK, PD, efficacy, or safety. The patisiran dosing regimen of 0.3 mg/kg every 3 weeks is appropriate for all patients with hATTR amyloidosis.

Pharmacokinetics of Patisiran, the First Approved RNA Interference Therapy in Patients With Hereditary Transthyretin-Mediated Amyloidosis

Hereditary transthyretin‐mediated (hATTR) amyloidosis is a rare, inherited, progressively debilitating, and often fatal disease caused by deposition of mutated transthyretin (TTR) protein. Patisiran is an RNA interference therapeutic comprising a novel small interfering ribonucleic acid (ALN‐18328) formulated with 2 novel lipid excipients, DLin‐MC3‐DMA and PEG₂₀₀₀‐C‐DMG, in a lipid nanoparticle targeted to inhibit hepatic TTR synthesis. Here we report the pharmacokinetics (PK) of ALN‐18328, DLin‐MC3‐DMA, and PEG₂₀₀₀‐C‐DMG from a phase 2 multiple‐ascending‐dose study and its open‐label extension (OLE) in patients with hATTR amyloidosis. Twenty‐nine patients received 2 intravenous infusions of patisiran of 0.01, 0.05, 0.15, or 0.3 mg/kg at 3‐ or 4‐week intervals; of these, 27 patients received 0.3 mg/kg once every 3 weeks over 24 months in the OLE study. Plasma PK profiles of ALN‐18328 and DLin‐MC3‐DMA exhibited 2 phases, the first characterized by a short distribution half‐life and the second by a minor peak and relatively long terminal elimination half‐life. PK exposures to 3 analytes increased proportionally across the dose range of 0.01 to 0.3 mg/kg. For ALN‐18328, mean terminal elimination half‐life was 3.2 days, mean total clearance was 3.0 mL/h/kg, and urinary excretion was negligible. All 3 analytes exhibited stable PK profiles with chronic dosing over 2 years. The 2‐ to 3‐fold plasma accumulation (AUC_τ) of ALN‐18328 at steady state is attributable to the association of ALN‐18328 with the cationic lipid DLin‐MC3‐DMA. There was no appreciable accumulation of PEG₂₀₀₀‐C‐DMG.

Analysis of autonomic outcomes in APOLLO, a phase III trial of the RNAi therapeutic patisiran in patients with hereditary transthyretin-mediated amyloidosis

Hereditary transthyretin-mediated (hATTR) amyloidosis is a progressive, debilitating disease often resulting in early-onset, life-impacting autonomic dysfunction. The effect of the RNAi therapeutic, patisiran, on autonomic neuropathy manifestations in patients with hATTR amyloidosis with polyneuropathy in the phase III APOLLO study is reported. Patients received patisiran 0.3 mg/kg intravenously (n = 148) or placebo (n = 77) once every 3 weeks for 18 months. Patisiran halted or reversed polyneuropathy and improved quality of life from baseline in the majority of patients. At baseline, patients in APOLLO had notable autonomic impairment, as demonstrated by the Composite Autonomic Symptom Score-31 (COMPASS-31) questionnaire and Norfolk Quality of Life-Diabetic Neuropathy (Norfolk QOL-DN) questionnaire autonomic neuropathy domain. At 18 months, patisiran improved autonomic neuropathy symptoms compared with placebo [COMPASS-31, least squares (LS) mean difference, − 7.5; 95% CI: − 11.9, − 3.2; Norfolk QOL-DN autonomic neuropathy domain, LS mean difference, − 1.1; − 1.8, − 0.5], nutritional status (modified body mass index, LS mean difference, 115.7; − 82.4, 149.0), and vasomotor function (postural blood pressure, LS mean difference, − 0.3; − 0.5, − 0.1). Patisiran treatment also led to improvement from baseline at 18 months for COMPASS-31 (LS mean change from baseline, − 5.3; 95% CI: − 7.9, − 2.7) and individual domains, orthostatic intolerance (− 4.6; − 6.3, − 2.9) and gastrointestinal symptoms (− 0.8; − 1.5, − 0.2). Rapid worsening of all study measures was observed with placebo, while patisiran treatment resulted in stable or improved scores compared with baseline. Patisiran demonstrates benefit across a range of burdensome autonomic neuropathy manifestations that deteriorate rapidly without early and continued treatment.

Blood pressure and orthostatic hypotension as measures of autonomic dysfunction in patients from the transthyretin amyloidosis outcomes survey (THAOS)

INTRODUCTION

Autonomic dysfunction, an early symptom of transthyretin amyloidosis (ATTR amyloidosis), requires investigations not readily available in many clinics. Although monitoring of orthostatic hypotension (OH) will not be a substitute for more specialized tests, it can add important information about initiation of dysautonomia. The aim of this study was to investigate whether simple blood pressure (BP) monitoring may be a useful tool for evaluation of disease progression and an early sign of autonomic dysfunction.

METHODS

BP and OH data were from subjects enrolled in the Transthyretin Amyloidosis Outcomes Survey (THAOS). Characteristics associated with changes in BP and orthostatic difference were identified by regression analyses.

RESULTS

OH tended to be present relatively early in the course of disease and was more common at enrollment (11.7%) than either diarrhea (2.4%) or unintentional weight loss (3.1%). In subjects with OH at enrollment, progressive increase in systolic and diastolic orthostatic difference was observed. OH was also associated with significantly worse quality of life.

DISCUSSION

BP variability is a useful tool for assessing disease onset and severity in ATTR amyloidosis, particularly in patients with OH. Trial registration ClinicalTrials.gov: NCT00628745.

Evaluating Prognostic Factors for Liver Transplantation Among United States Patients With Hereditary Transthyretin-Mediated (hATTR) Amyloidosis Using National Registry Data

INTRODUCTION

Orthotopic liver transplantation has been used as a treatment for hereditary transthyretin-mediated (hATTR) amyloidosis, a rare, progressive, and multisystem disease.

RESEARCH QUESTION

The objective is to evaluate survival outcomes post-liver transplantation in patients with hATTR amyloidosis in the United States and assess whether previously published prognostic factors of patient survival in hATTR amyloidosis are generalizable to the US population.

DESIGN

This cohort study examined patients with hATTR amyloidosis undergoing liver transplant in the United States (N = 168) between March 2002 and March 2016 using data reported to the Organ Procurement and Transplantation Network (UNOS)/United Network for Organ Sharing (OPTN).

RESULTS

A multivariable Cox hazards regression model showed among all factors tested, only modified body mass index (kg/m² × g/L) at the time of transplant was significantly associated with survival. Higher modified BMI was associated with lower risk of death relative to a reference population (<600) with historically poor post-transplant outcomes. Patients with modified BMI 1000 to <1200 (hazard ratio [HR] = 0.27; 95% confidence interval [CI] = 0.10-0.73), 1200 to <1400 (HR = 0.20; 95% CI = 0.06-0.75), and ≥1400 (HR = 0.15; 95% CI = 0.04-0.61) exhibited improved adjusted 5-year post-transplant survival of 74%, 80%, and 85%, respectively, versus 33% in the reference population.

DISCUSSION

The association between a higher modified BMI threshold at the time of transplant and improved post-transplant survival suggests that the previously published patient selection criterion for modified BMI may not be applicable to the US population.

Patisiran, an RNAi therapeutic for the treatment of hereditary transthyretin-mediated amyloidosis

Hereditary transthyretin-mediated amyloidosis is a rapidly progressive, heterogeneous disease caused by the accumulation of misfolded transthyretin protein as amyloid fibrils at multiple sites, and is characterized by peripheral sensorimotor neuropathy, autonomic neuropathy and/or cardiomyopathy. Current treatment options have limited efficacy and often do not prevent disease progression. Patisiran is a novel RNA interference therapeutic that specifically reduces production of both wild-type and mutant transthyretin protein. In Phase II, III and long-term extension studies in patients with hereditary transthyretin-mediated amyloidosis, patisiran has consistently slowed or improved progression of neuropathy. In addition, the Phase III trial demonstrated significant improvements in quality of life measures and indicators of cardiomyopathy. Here, we highlight efficacy and safety data from the patisiran clinical trial programme.

Autonomic involvement in hereditary transthyretin amyloidosis (hATTR amyloidosis)

PURPOSE

Hereditary transthyretin amyloidosis (hATTR amyloidosis) is a progressive disease primarily characterized by adult-onset sensory, motor, and autonomic neuropathy. In this article, we discuss the pathophysiology and principal findings of autonomic neuropathy in hATTR amyloidosis, the most common methods of assessment and progression, and its relation as a predictive risk factor or a measure of progression in the natural history of the disease.

METHODS

A literature search was performed using the terms "autonomic neuropathy," "dysautonomia," and "autonomic symptoms" in patients with hereditary transthyretin amyloidosis and familial amyloid polyneuropathy.

RESULTS

Various scales to measure autonomic function have been employed, particularly within the major clinical trials, to assess novel therapies for the disease. Most of the evaluations were taken from diabetic clinical trials. Questionnaires include the COMPASS-31 and Norfolk QOL autonomic nerve function domain, whereas clinical evaluations comprise HRDB and the orthostatic tolerance test. Several treatment options are being employed although only diflunisal and tafamidis have reported improvement in the autonomic abnormalities.

CONCLUSIONS

Autonomic nerves are often affected before motor nerve impairment, and dysautonomia may support the diagnosis of hATTR amyloidosis when differentiating from other adult-onset progressive neuropathies and from other types of amyloidosis. Most of the progression of autonomic dysfunction is seen in early stages of the disease, commonly before motor impairment or affection of the overall quality of life. Unfortunately, there is no current single standardized approach to evaluate dysautonomia in hATTR amyloidosis.

Clinical measures in transthyretin familial amyloid polyneuropathy

INTRODUCTION

This observational, cross-sectional, single-center study aimed to identify instruments capable of measuring disease progression in transthyretin familial amyloid polyneuropathy (TTR-FAP).

METHODS

The relationship between disease stage and Neuropathy Impairment Score-Lower Limbs (NIS-LL) and Norfolk Quality of Life-Diabetic Neuropathy (Norfolk QOL-DN) total score was assessed in 61 (stages 1-3) patients with TTR-FAP (V30M variant) and 16 healthy controls. Composite measures of large- and small-nerve fiber function, and modified body mass index (mBMI) were also assessed.

RESULTS

Ordinal-based NIS-LL and Norfolk QOL-DN scores discriminated between disease stages (P < 0.0001 for NIS-LL and Norfolk QOL-DN). Longer disease duration correlated with worse NIS-LL and Norfolk QOL-DN. Karnofsky performance score declined progressively by disease stage. Composite measures of nerve fiber function differentiated stage 1 from stage 2 disease. The mBMI declined with advancing disease.

CONCLUSIONS

NIS-LL, Norfolk QOL-DN score, composite endpoints of nerve fiber function, and mBMI are valid, reliable measures of TTR-FAP severity. Muscle Nerve 55: 323-332, 2017.

Domino Liver Transplantation: A Practical Option in the Face of the Organ Shortage

This case study describes a domino liver transplantation in which a patient with familial amyloid polyneuropathy received a cadaveric liver, and the explanted liver was in turn transplanted into a second recipient. Familial amyloid polyneuropathy is an autosomal dominant inherited disease associated with a mutant form of the protein transthyretin. Liver transplantation is the only definitive treatment for this disease. Transplantation removes the source of mutant transthyretin, halts the progression of this otherwise fatal disease, and significantly palliates many underlying symptoms. This case study illustrates that domino transplantation is a practical option to provide a liver transplant for a patient with this disease and a second listed patient from a single cadaveric liver organ, thus alleviating the organ donor shortage. Transplantation offers the only cure for the genetic defect that causes familial amyloid polyneuropathy, appears to result in subjective and objective improvement in neurological function, and eliminates the mortality associated with the disease. A signed informed consent was provided for publication of this case study.

Subaortic membrane mimicking hypertrophic cardiomyopathy

A 34-year-old man was referred for progressive angina and exertional dyspnoea refractory to medical therapy, with a presumptive diagnosis of hypertrophic cardiomyopathy (HCM). Transthoracic echocardiography (TTE) revealed asymmetric septal hypertrophy without systolic anterior motion of the mitral valve leaflet and with no dynamic left ventricular outflow tract (LVOT) obstruction. However, the LVOT velocity was elevated at rest as well as with provocation, without the characteristic late peaking obstruction seen in HCM. Focused TTE to evaluate for suspected fixed obstruction demonstrated a subaortic membrane 2.2 cm below the aortic valve. Coronary CT angiography confirmed the presence of the subaortic membrane and was negative for concomitant coronary artery disease. Surgical resection of the subaortic membrane and septal myectomy resulted in significant symptomatic relief and lower LVOT velocities on postoperative TTE. This case reminds the clinician to carefully evaluate for alternative causes of LVOT obstruction, especially subaortic membrane, as a cause of symptoms mimicking HCM.

Amyloidosis involving the respiratory system: 5-year's experience of a multi-disciplinary group's activity

Amyloidosis may involve the respiratory system with different clinical-radiological-functional patterns which are not always easy to be recognized. A good level of knowledge of the disease, an active integration of the pulmonologist within a multidisciplinary setting and a high level of clinical suspicion are necessary for an early diagnosis of respiratory amyloidosis. The aim of this retrospective study was to evaluate the number and the patterns of amyloidosis involving the respiratory system. We searched the cases of amyloidosis among patients attending the multidisciplinary rare and diffuse lung disease outpatients' clinic of Pulmonology Unit of the Hospital of Arezzo from 2007 to 2012. Among the 298 patients evaluated during the study period, we identified three cases of amyloidosis with involvement of the respiratory system, associated or not with other extra-thoracic localizations, whose diagnosis was histo-pathologically confirmed after the pulmonologist, the radiologist, and the pathologist evaluation. Our experience of a multidisciplinary team confirms that intra-thoracic amyloidosis is an uncommon disorder, representing 1.0% of the cases of rare and diffuse lung diseases referred to our center. The diagnosis of the disease is not always easy and quick as the amyloidosis may involve different parts of the respiratory system (airways, pleura, parenchyma). It is therefore recommended to remind this orphan disease in the differential diagnosis of the wide clinical scenarios the pulmonologist may intercept in clinical practice.

Hereditary ATTR amyloidosis: a single-institution experience with 266 patients

BACKGROUND

Hereditary transthyretin amyloidosis (ATTR amyloidosis) is a rare, clinically heterogeneous disease due to heritable mutations that lead to misfolding of a precursor protein and multisystem disease. This study sought to define the clinical characteristics, distribution of mutations and phenotypic presentation of patients presenting to our center with hereditary ATTR amyloidosis.

METHODS

With institutional review board approval, the study retrospectively identified patients who had hereditary ATTR amyloidosis and presented to Mayo Clinic in Rochester, Minnesota, from 1 January 1970, to 29 January 2013.

RESULTS

Of the 266 patients with the diagnosis of hereditary ATTR amyloidosis, a pathogenic mutation was identified in 206; the most common mutation was Thr60Ala (68 patients [25%]). Median age at diagnosis was 63.3 years; median survival after diagnosis was 56.8 months (10th-90th percentile, 16.0-297.9). On multivariate analysis, age at diagnosis (risk ratio, 15.65; p < 0.0001), Thr60Ala mutation (risk ratio, 1.52; p = 0.04), Val122Ile mutation (risk ratio, 2.83; p = 0.003), peripheral neuropathy (risk ratio, 1.69; p = 0.013) and weight loss (risk ratio, 1.81; p = 0.002) were risk factors for death.

CONCLUSION

Our data characterize the features of hereditary ATTR amyloidosis in a large cohort, demonstrate the heterogeneity among mutations and support the need to better characterize the clinical progression of individual mutations.

Recent advances in the diagnosis and management of cardiac amyloidosis

The heart is commonly involved in various forms of amyloidosis and cardiomyopathy is a major cause of morbidity and mortality in these patients. Diagnosis of cardiac amyloidosis is often delayed due to nonspecific presenting symptoms and failure to recognize early signs of amyloid heart disease on routine cardiac imaging. Treatment of cardiac amyloidosis depends upon the type of amyloid protein. Systemic chemotherapy with or without stem cell transplantation is used to treat immunoglobulin-related amyloidosis and liver transplantation is used for familial transthyretin amyloidosis in select patients. Clinical trials with siRNA for the treatment of transthyretin amyloid cardiomyopathies and amyloid protein stabilizers are ongoing. Prognosis depends on the type of amyloid protein with poorer outcomes noted in immunoglobulin light-chain amyloidosis. Supportive care forms the cornerstone of management and advancements in cardiac imaging and proteomics are expected to positively impact our ability to diagnose, prognosticate and treat cardiac amyloidosis.

Nuclear imaging modalities for cardiac amyloidosis

Amyloidosis is a heterogeneous group of diseases characterized by localized or systemic deposition of insoluble extracellular fibrillary proteins in organs and tissues. Several types of amyloid can infiltrate the heart resulting in a restrictive cardiomyopathy, heart failure, and atrial and ventricular arrhythmias. Scintigraphy is a noninvasive method that may facilitate early diagnosis, distinguish various forms of cardiac amyloid, and may be useful in following disease burden. The amyloid-specific tracers presented in this article have been used with planar imaging and/or single-photon emission computed tomography. To date, there are no approved cardiac amyloid tracers although investigational tracers are currently under examination. This article serves to review the current nuclear imaging modalities available in the detection of cardiac amyloid.

Tissue Doppler is a More Reliable Method in Early Detection of Cardiac Dysfunction in Patients with AA Amyloidosis

OBJECTIVE

Cardiac deposition of AA amyloidosis may result in increasing left ventricular mass and systolic and diastolic dysfunction (DD). The aim of this study was to investigate the left ventricular systolic and diastolic functions by both tissue Doppler imaging (TDI) and pulsed wave Doppler echocardiography (PWD) in patients with AA amyloidosis without congestive heart failure symptoms or arrthymia.

METHODS AND RESULTS

Twenty-four patients with AA amyloidosis without congestive heart failure symptoms or arrthymia (15 men and nine women; mean age 44.3 +/- 16.7 years) and 25 healthy subjects (19 men and six women; mean age 43.1 +/- 9.2 years) as controls were included in the study. M-mode, two-dimensional, PWD, and TDI were performed. Peak transmitral filling velocity (E wave), peak transmitral atrial filling velocity (A wave), deceleration time, and isovolumic relaxation time were measured by PWD recordings. Peak myocardial systolic velocity (Sm), peak myocardial early (Em), and late diastolic velocities (Am) were also recorded by TDI. E/A ratio less than one was accepted as DD for both methods. Ejection fraction (EF) was calculated by Teicholtz method. The subjects were divided into three groups as follows: healthy controls (group 1), patients without DD (group 2), and patients with DD (group 3) according to the PWD findings. PWD echocardiography showed that DD was present in 50% of the patients, whereas TDI showed DD in 66% of such cases. In subgroup analysis, Sm wave as a systolic function index was lower in group 3 than in groups 1 and 2, whereas mean EF values were similar in all groups.

CONCLUSION

Although AA amyloidosis uncommonly causes cardiac symptoms and findings, according to our results, patients with AA amyloidosis may have systolic and diastolic dysfunction eventhough they are asymptomatic. Also, tissue Doppler imaging is a more reliable method in the early detection of cardiac dysfunction in such patients.

Patterns of neuropathy and autonomic failure in patients with amyloidosis

OBJECTIVE

To define the clinical patterns of peripheral neuropathy and autonomic testing abnormalities in patients with amyloidosis.

PATIENTS AND METHODS

A retrospective chart review was conducted of 65 patients who had biopsy-proven amyloidosis and autonomic function testing between January 1, 1985, and December 31, 1997, at Mayo Clinic's site in Rochester, MN. Patients were required to have neurologic evaluation, autonomic reflex screening, and tissue confirmation of amyloidosis.

RESULTS

We identified 5 clinical patterns of peripheral neuropathy: (1) generalized autonomic failure and polyneuropathy with pain (40 patients [62%]), (2) generalized autonomic failure and polyneuropathy without pain (11 [17%]), (3) isolated generalized autonomic failure (7 [11%]), (4) polyneuropathy without generalized autonomic failure (4 [6%]), and (5) generalized autonomic failure and small-fiber (ie, autonomic and somatic C-fiber) neuropathy (3 [5%]). Moderately severe generalized autonomic failure, involving adrenergic, cardiovagal, or sudomotor domains, was found in all patients, including those without clinically manifested autonomic failure. The diagnosis of amyloidosis was delayed in patients who did not have initial symptoms of pain or generalized autonomic failure (48 months to diagnosis in patients with polyneuropathy without autonomic failure vs 12 months to diagnosis in patients with autonomic failure and small-fiber neuropathy; P=.57).

CONCLUSION

Physicians should test for symptoms of generalized autonomic failure in patients who have peripheral neuropathy of unknown origin. Autonomic testing may give abnormal results in patients without overt symptoms of autonomic failure. Early recognition of autonomic failure may lead to earlier diagnosis of the underlying pathogenesis of amyloidosis, as well as earlier treatment for patients with this condition.

Les amyloses à transthyrétine

PURPOSE

Transthyretin amyloidoses are the most common form of amyloidosis. Two different types of transthyretin amyloidoses are described, one is rare, familial, its precursor is the mutated transthyretin, this type is called transthyretin amyloid, the other is more common, its precursor is wild transthyretin, this second type is called senile amyloid. The review describes the molecular, clinical and evolutives features of both types.

CURRENT KNOWLEDGE AND KEY POINTS

Transthyretin is a naturally beta-pleated protein. Reported mutations increase its proteolysis resistance and its ability to form amyloid deposits. While transthyretin amyloid is clinically aggressive (neuropathy, cardiomyopathy, nephropathy, and vitreous deposits), senile amyloid is slightly symptomatic (rarely congestive heart failure). The differential diagnosis is essentially based on molecular biology.

FUTURE PROSPECTS AND PROJECTS

Liver transplantation is an effective treatment of transthyretin amyloid because it switches the mutated protein synthesis to the wild protein synthesis. Liver transplantation is sometimes associated with cardiac or kidney transplantation depending of the clinical presentation. Concerning a specific treatment, P component analogous are developed for inhibiting amyloid deposits formation. Tetrameric transthyretin structure stabilisators are in development.

Sudden death in nondilated cardiomyopathies: pathophysiology and prevention

Sudden cardiac death is a frequent cause of death and has been well studied in the setting of both ischemic and dilated cardiomyopathies. The primary and secondary prevention of sudden cardiac death has not been the focus of randomized clinical trials in the large cohort of patients with nondilated, nonischemic cardiomyopathies, however. Those disorders include hypertrophic cardiomyopathy and its apical variant, arrhythmogenic right ventricular cardiomyopathy, takotsubo cardiomyopathy, left ventricular noncompaction, cardiac amyloidosis, and cardiac sarcoidosis. In these conditions, risk stratification for sudden death is based on observational data.

Extended phenotype in the transthyretin Tyr77 familial amyloid polyneuropathy

The transthyretin Tyr77 variant of familial amyloid polyneuropathy (FAP) has been identified in a few North American and European patients, but the full spectrum of its clinical manifestations is still not known. We report a 3-generation family of Jewish-Yemenite origin with Tyr77 FAP presenting with atypical features. The affected individuals had sensorimotor and autonomic neuropathy and cardiomyopathy accompanied by prominent dysphagia, hearing loss and asymptomatic carpal tunnel syndrome. Brain MRI in the proband showed multifocal white matter lesions. These features extend the reported Tyr77 phenotype and support the modifying effect of additional factors on the disease expression.

Neurodegeneration in familial amyloid polyneuropathy: from pathology to molecular signaling

Familial amyloid polyneuropathy (FAP) is an autosomal dominant neurodegenerative disorder related to the systemic deposition of mutated transthyretin (TTR) amyloid fibrils, particularly in peripheral nervous system (PNS). TTR fibrils are diffusely distributed in the PNS of FAP patients, involving nerve trunks, plexuses and ganglia. In peripheral nerves, amyloid deposits are prominent in the endoneurium, near blood vessels, Schwann cells and collagen fibrils. Fiber degeneration is axonal, beginning in the unmyelinated and low diameter myelinated fibers. Several hypotheses have been raised to explain axonal and neuronal loss: (i) compression of the nervous tissue by amyloid; however, a cause-effect relationship between amyloid deposition, structural nerve changes and degeneration was never clearly made; (ii) role of nerve ischemia secondary to lesions caused by perivascular amyloid, which is also doubtful as compromised blood flow was never demonstrated; (iii) lesions in the dorsal root ganglia neurons or Schwann cells. Recently, evidence for the presence of toxic non-fibrillar TTR aggregates early in FAP nerves constituted a first step to unravel molecular signaling related to neurodegeneration in FAP. The toxic nature of TTR non-fibrillar aggregates, and not mature TTR fibrils, was evidenced by their ability to induce the expression of oxidative stress and inflammation-related molecules in neuronal cells, driving them into apoptotic pathways. How these TTR aggregates exert their effects is debatable; interaction with cellular receptors, namely, the receptor for advanced glycation endproducts (RAGE), is a probable candidate mechanism. The pathology and the yet unknown molecular signaling mechanisms responsible for neurodegeneration in FAP are discussed.

Domino liver transplantation: a practical option in the face of the organ shortage

This case study describes a domino liver transplantation in which a patient with familial amyloid polyneuropathy received a cadaveric liver, and the explanted liver was in turn transplanted into a second recipient. Familial amyloid polyneuropathy is an autosomal dominant inherited disease associated with a mutant form of the protein transthyretin. Liver transplantation is the only definitive treatment for this disease. Transplantation removes the source of mutant transthyretin, halts the progression of this otherwise fatal disease, and significantly palliates many underlying symptoms. This case study illustrates that domino transplantation is a practical option to provide a liver transplant for a patient with this disease and a second listed patient from a single cadaveric liver organ, thus alleviating the organ donor shortage. Transplantation offers the only cure for the genetic defect that causes familial amyloid polyneuropathy, appears to result in subjective and objective improvement in neurological function, and eliminates the mortality associated with the disease. A signed informed consent was provided for publication of this case study.

Non-cancerous ophthalmic clues to non-ocular cancer

This survey reviews selected medical disorders in which the ophthalmologist has a unique opportunity of anticipating the existence of asymptomatic, life-threatening disease simply by recognizing that certain benign conditions involving the eye or adnexa represent clues to occult non-ocular cancer and other neoplasias. Having knowledge that these clues are associated with specific types of neoplasia, the ophthalmologist can then initiate a goal-directed oncologic investigation designed to identify the underlying neoplasm with the hope of providing potentially life-saving therapy. The survey is organized to feature each clue separately. The clinical characteristics of the clue are described and illustrated with color photographs when possible. A discussion reviews associated malignancies and other important medical features. The survey begins with clues expressed anteriorly in the lids, progressively reviewing those clues located more posteriorly, concluding with clues involving the retinal pigment epithelium and choroid.

Clinical variant of familial amyloid polyneuropathy

Hereditary amyloidosis with early and prominent peripheral nerve involvement is often designated familial amyloid polyneuropathy (FAP). The abnormality usually lies in the transthyretin (TTR) gene. We describe a patient with a tyr77 TTR gene mutation who presented with sensorimotor polyneuropathy but no other systemic symptoms of amyloidosis. This is one of a few documented cases of the tyr77 mutation in North America. The clinical and electrophysiologic features of this unusual cause of sensorimotor polyneuropathy are discussed.

Review: small-fiber neuropathy

BACKGROUND

Most peripheral neuropathies involve large as well as small-fiber dysfunction. A small subset of neuropathies present with restricted or predominant small-fiber involvement.

REVIEW SUMMARY

In this review, we discuss the differential diagnosis, clinical presentation, evaluation, and treatment of small-fiber neuropathies. Although these neuropathies are rare, their differential diagnosis is broad, and includes many disorders, including metabolic, toxic, inflammatory, infectious, and genetic etiologies. As small fibers subserve pain and autonomic functions, these neuropathies usually present with pain and temperature loss, painful dysesthesias, autonomic dysfunction, or a combination. These neuropathies are especially challenging as nerve conductions and EMG, which help guide the evaluation of most peripheral neuropathies, may have normal findings in patients with small-fiber neuropathies. Other specialized studies, including tests of autonomic function, intraepidermal nerve fiber analysis, and quantitative sensory testing, are often required to confirm the presence of a small-fiber neuropathy. In some cases, the underlying etiology can be directly treated. In most, management is limited to symptomatic treatment of sensory and autonomic dysfunction.

CONCLUSION

Small-fiber neuropathies are a heterogeneous group of disorders. They vary in etiologies and require special attention, as many disorders are rare and the differential diagnosis is broad. Evaluation is often extensive and may need pathologic specimen. Many patients respond to symptomatic therapy, but some are difficult to treat.

Heart rate variability and familial amyloidosis

A 32-year-old man with family history of amyloidosis was admitted to the hospital because of orthostatic hypotension. An echocardiogram was suggestive for cardiac amyloidosis. Heart rate variability analysis, performed on 24-h Holter monitoring, showed markedly low values in both frequency and time domain, reflecting a severe autonomic nervous system dysfunction.

Sympathetic skin responses in hereditary sensory and autonomic neuropathy and familial amyloid neuropathy are different

We compared the clinical and electrophysiological findings in seven patients with familial amyloid polyneuropathy (FAP) and six with hereditary sensory and autonomic neuropathy type I (HSAN). Both groups had progressive loss of pain and temperature appreciation, beginning distally in the feet. In HSAN, the median sensory nerve action potentials (SNAP) were lost early, but the sympathetic skin responses (SSR) were always preserved. In FAP, the SSR were lost at an early stage. The SSR may thus help to distinguish between these two causes of small-fiber neuropathy early in the course of the disorder.

Progression of cardiomyopathy and neuropathy after liver transplantation in a patient with familial amyloidotic polyneuropathy caused by tyrosine-77 transthyretin variant

Familial amyloidotic polyneuropathy is an inherited form of amyloidosis associated with a mutant form of a protein called transthyretin. The Methionine-30 variant is the most frequent mutation observed. This disorder is caused by deposition of this protein as amyloid in several organs, such as the heart, kidneys, and peripheral nervous system. The disease is always progressive and fatal, and patients die 7 to 10 years after the onset of symptoms. Liver transplantation is at present the only choice for these patients because it provides improvement of symptoms and/or stops progression of the disease in most patients. We report the case of a patient who showed clear progression of cardiomyopathy and neuropathy after liver transplantation.

Hypertrophic and restrictive cardiomyopathies in the elderly

Congestive heart failure (CHF) increases with age, but most CHF in the elderly is due to diastolic dysfunction with preserved systolic function. The etiology, pathophysiology, diagnosis, natural history, and treatment of hypertrophic and restrictive cardiomyopathies in the elderly are discussed as a paradigm for CHF with normal systolic function. Hypertrophic obstructive and hypertensive hypertrophic cardiomyopathies are compared and contrasted. As an example of a restrictive cardiomyopathy, the various types of amyloidosis and their clinical import in older patients are covered.

Familial amyloid with a transthyretin leucine 33 mutation presenting with ascites

A 65-year-old female presented with symptomatic ascites. Light and electron microscopy examination of omental and peritoneal tissue obtained at exploratory laparotomy revealed amyloidosis. Immunochemical studies of the amyloid tissue showed positive staining with antibodies to transthyretin. Polymerase chain reaction (PCR), single strand conformation polymorphism analysis, and direct DNA sequencing demonstrated a transthyretin phenylalanine to leucine substitution at codon 33. This is only the second reported case of a transthyretin leucine 33 mutation. Moreover, this patient is unique among cases of transthyretin-associated amyloidosis with the clinical presentation of ascites.