Perfis clínicos e genéticos de pacientes com amiloidose transtiretina hereditária e do tipo selvagem: o registro de amiloidose cardíaca transtiretina no Estado de São Paulo, Brasil (REACT-SP) / Clinical and genetic profiles of patients with hereditary and wild-type transthyretin amyloidosis: the transthyretin cardiac amyloidosis registry in the State of São Paulo, Brazil (REACT-SP)

INTRODUÇÃO: A amiloidose transtiretina (ATTR) é uma doença multissistêmica causada pela deposição de proteína fibrilar em órgãos e tecidos. Os genótipos e fenótipos da ATTR são altamente heterogêneos. MÉTODOS: Apresentamos dados sobre sinais e sintomas físicos, avaliações cardíacas e neurológicas, e genética em pacientes incluídos no Registro de Amiloidose Cardíaca Transtiretina no Estado de São Paulo (REACT-SP), Brasil. RESULTADOS: Foram incluídos 644 pacientes, sendo 505 com a forma variante (ATTRv) e 139 com a forma selvagem (ATTRwt). Dezesseis mutações diferentes foram detectadas, sendo as mais comuns Val50Met (48,3%) e V142Ile (40,8%). No geral, mais da metade dos pacientes apresentou envolvimento cardíaco, e a diferença nessa proporção entre os grupos ATTRv e ATTRwt foi significativa (43,9 vs. 89,9%; p<0,001). O fenótipo neurológico também diferiu entre ATTRv e ATTRwt (56,8 vs. 31,7%; p<0,001). O fenótipo misto foi encontrado em 25,6% da população, sem diferença significativa entre as formas de amiloidose. Um grupo de pacientes permaneceu assintomático (10,4%), com uma proporção menor de pacientes assintomáticos no grupo ATTRwt. CONCLUSÕES: Este estudo detalha o espectro clínico e genético de pacientes com ATTR em São Paulo, Brasil. Esta análise preliminar destaca a considerável heterogeneidade fenotípica das manifestações neurológicas e cardíacas em pacientes com ATTR variante e ATTR do tipo selvagem.

Ocorrência rara de amiloidose por transtirretina na segunda década de vida / Rare occurrence of transthyretin amyloidosis in the second decade of life

INTRODUÇÃO: Sendo p.V50M e p.V142I as variantes mais comuns associadas à amiloidose por transtirretina hereditária (ATTRh), pode haver uma errônea correlação de que a doença se manifeste apenas em idosos já que a apresentação clínica em seus portadores geralmente se inicia tardiamente, em meia idade e acima de 60 anos, respectivamente. Entretanto, existem outras variantes que podem determinar quadro clínico mais grave e precoce. Descrevemos uma série de casos com início em idade inferior a 25 anos associados à identificação de variante rara no gene TTR. MÉTODOS: Estudo observacional de série de casos RESULTADOS: Três pacientes (p) masculinos, aparentados, portadores de ATTRh confirmada por teste molecular positivo para a variante patogênica p.F64S, com idade média de apresentação clínica de 19±3 anos. Características basais dos p expressas na tabela 1. Todos os p apresentavam fenótipo misto, sendo portadores de polineuropatia grave, disautonomia (expressa por disfunção erétil, hipotensão e alterações digestivas) e cardiopatia em graus variáveis, mais evidente no p com instalação da doença há mais tempo. Espessura média do septo de 15,6±4 mm e de 13±3 mm, da parede posterior. Um p apresentou derrame pericárdico volumoso recorrente. Nenhum óbito ocorreu durante o seguimento. Todos os p receberam tratamento específico para amiloidose: o caso índice foi submetido a transplante hepático, outro está recebendo um silenciador gênico (eplontersen em protocolo clínico) e, o último, em uso de tafamidis 20mg. DISCUSSÃO E CONCLUSÃO: descrevemos 3 p aparentados, que apresentaram os primeiros sintomas de ATTRh aos 20 anos de idade com fenótipo misto (polineuropatia e cardiopatia), determinada pela variante p.F64S. Esta variante é muito rara e encontramos 7 casos descritos na Literatura, todos muito jovens que apresentaram fenótipo predominante de polineuropatia, mas a maioria com cardiopatia associada. A variante p.V50M também pode ocorrer em jovens na forma precoce da doença, porém isto ocorre em torno da terceira década de vida. Conclui-se que a amiloidose não deve ser encarada como uma doença exclusiva da população idosa. A forma hereditária pode ocorrer em p mais jovens e a idade de início do quadro dependerá da variante encontrada. Deve-se, portanto, considerar amiloidose como diagnóstico diferencial das hipertrofias ventriculares em jovens.

Macular amyloidosis diagnostic outcomes of skin biopsy: A systematic review.

Macular amyloidosis (MA) is a primary localized cutaneous amyloidosis, characterized by amyloid deposition in the papillary dermis. The clinical presentation includes pruritic hyperpigmented macules and patches with a reticulated or rippled pattern, primarily found on the upper back and extremities. Biopsy is an essential diagnostic tool for confirming MA. This systematic review focused on the biopsy outcomes in patients diagnosed with MA.

Efficacy of topical gabapentin in women with primary macular amyloidosis: A side-by-side triple-blinded randomized clinical trial.

BACKGROUND: Primary cutaneous macular amyloidosis (PCMA) is a chronic pruritic cutaneous disease characterized by heterogeneous extracellular deposition of amyloid protein in the skin. AIMS: This study aimed to evaluate the efficacy of topical 6% gabapentin cream for the treatment of patients with PCMA. MATERIALS AND METHODS: In this triple-blind clinical trial, a total of 34 patients, who were diagnosed with PCMA, treated using two different strategies of topical gabapentin as the active group and vehicle cream as the control group. RESULTS: Pruritus score reduction in both groups was statistically significant compared with the baseline value (p < 0.001). There was a significant pigmentation score reduction in intervention group compared with control group after 1 month of the study (p < 0.001). The differences of pigmentation score changes between the groups were not significant at month 2 (p = 0.52) and month 3 (p = 0.22). CONCLUSIONS: The results of this study suggest that topical gabapentin cream may be effective as a topical agent in the treatment of pruritus associated with PCMA without any significant adverse effects. It is recommended to perform similar studies with a larger sample size and longer duration in both sexes.

Trypsin-induced aggregation of transthyretin Valine 30 variants associated with hereditary amyloidosis.

Amyloid fibrils of transthyretin (TTR) consist of full-length TTR and C-terminal fragments starting near residue 50. However, the molecular mechanism underlying the production of the C-terminal fragment remains unclear. Here, we investigated trypsin-induced aggregation and urea-induced unfolding of TTR variants associated with hereditary amyloidosis. Trypsin strongly induced aggregation of variants V30G and V30A, in each of which Val30 in the hydrophobic core of the monomer was mutated to less-bulky amino acids. Variants V30L and V30M, in each of which Val30 was mutated to bulky amino acids, also exhibited trypsin-induced aggregation. On the other hand, pathogenic variant I68L as well as the nonpathogenic V30I did not exhibit trypsin-induced aggregation. The V30G variant was extremely unstable compared with the other variants. The V30G mutation caused the formation of a cavity and the rearrangement of Leu55 in the hydrophobic core of the monomer. These results suggest that highly destabilized transthyretin variants are more susceptible to trypsin digestion.

Evaluation and comparison of Q-switched Nd: YAG laser 1064 nm and Er: YAG laser 2940 nm in the treatment of macular amyloidosis.

Macular amyloidosis (MA) is one of the most common types of primary localized cutaneous amyloidosis (PLCA), distributed predominantly over the trunk and extremities. Due to the vast therapeutic options, this study aims to compare the effectiveness of Q-switched Nd: YAG laser 1064 nm and Er: YAG laser 2940 nm in treating MA. This clinical trial was performed in 2020-2021 on 33 women with MA. In each patient, the lesion was randomly divided into two areas, A and B. Area A underwent four treatment sessions with 4-week intervals of Q-switched Nd: YAG laser 1064 nm. Area B underwent four treatment sessions with an Er: YAG laser 2940 nm at 4-week intervals. Degree of basal pigmentation and degree of pigmentation after treatment, pruritus intensity, before and after the treatment, and patient and physicians' satisfaction were measured and compared. The pruritus in patients improved significantly after the study (P < 0.001), but no significant differences could be observed between the two groups regarding the improvements (P > 0.05). We also found no significant differences between the two groups of patients regarding patient and physicians' satisfaction rates (P > 0.05). The use of both Q-switched Nd: YAG laser and Er: YAG laser resulted in improvements in terms of pruritus, patient and physicians' satisfaction, and total improvement in pigmentation of the lesions.

Using machine learning to assess potential cases of transthyretin cardiac amyloidosis in Brazil: a retrospective database approach

INTRODUCTION: Amyloidosis is a group of protein misfolding disorders leading to organ damage due to insoluble amyloid fibril deposits • The two primary types of cardiac amyloidosis are light-chain amyloid (AL) and transthyretin (TTR) cardiac amyloidosis • TTR amyloidosis can be hereditary (hATTR) or age-related (wtATTR). It is an often-overlooked cause of heart failure in older adults • Recent studies reveal its prevalence in various patient groups: up to 13% in HFpEF, 16% in aortic stenosis patients undergoing valve replacement, 7-8% in carpal tunnel release surgery, and 17% in some other contexts • ATTR-CM is significant in the context of cardiovascular diseases, a leading global cause of death. OBJECTIVE: This study aimed to identify and describe the profile of potential transthyretin cardiac amyloidosis (ATTR-CM) cases in the Brazilian public health system (SUS), using a predictive machine learning (ML) model. MATERIALS AND METHODS: This was a retrospective descriptive database study that aimed to estimate the frequency of potential ATTR-CM cases in the Brazilian public health system (Figure 1) using a supervised machine learning (Figure 2) model, with data extracted from DATASUS outpatient and inpatient datasets from January 2015 to December 2021 • To build the model, a list of ICD-10 codes and procedures potentially related with ATTR-CM was created based on literature review and validated by experts (Figure 3). RESULTS: From 2015 to 2021, the ML model classified 262 hATTR-CM (213 reference hATTR-CIM and 49 hATTR-CM-like) and 1,581 wtATTR-CM (203 reference wtATTR-CM and 1,378 wtATTR-CM-like). Overall, the median age of hATTR-CM and wtATTR-CM patients was 66.8 and 59.9 years, respectively • The ICD-10 codes most presented as hATTR-CM and wtATTR-CM were related to heart failure and arrythmias, with similar procedures performed (Figure 4). Regarding healthcare utilization, hATTR-CM and hATTR-CM-like had similar profiles on proportion of patients with outpatient visits (hATTR-CM 98.0% vs. 92.0% hATTR-CM-like) and different profile related to proportion of hospitalized patients (hATTR-CM 94.4% vs. 32.7% hATTR-CM-like) (Figure 5) • In wtATTR-CM groups, although both proportions on outpatient visits and hospitalizations were similar, the length of stay (LOS) on hospitalizations was different in wtATTR-CM-like (wtATTR-CM median LOS 5.0 (IQR:2.0 - 10.0] vs. median LOS 7.0 [IQR:3.0 - 14.0]). CONCLUSIONS: Our findings may be useful to support decreasing the uncertainties on ATTR-CM population size in Health Technology Assessment appraisals and in the development of healthcare guidelines and policies to address patients' unmet needs and to improve early diagnosis and access to treatment for patients with ATTR-CM in Brazil This study puts a spotlight on the ATTR-CM underdiagnosis in Brazil using a machine learning approach, which can be used as an important tool to support diagnosis improvement.

Single Nucleotide Polymorphisms Associated with AA-Amyloidosis in Siamese and Oriental Shorthair Cats.

AA-amyloidosis in Siamese and Oriental shorthair cats is a lethal condition in which amyloid deposits accumulate systemically, especially in the liver and the thyroid gland. The age at death of affected cats varies between one and seven years. A previous study indicated a complex mode of inheritance involving a major locus. In the present study, we performed a multi-locus genome-wide association study (GWAS) using five methods (mrMLM, FASTmrMLM, FASTmrEMMA, pLARmEB and ISIS EM-BLASSO) to identify variants associated with AA-amyloidosis in Siamese/Oriental cats. We genotyped 20 affected mixed Siamese/Oriental cats from a cattery and 48 healthy controls from the same breeds using the Illumina Infinium Feline 63 K iSelect DNA array. The multi-locus GWAS revealed eight significantly associated single nucleotide polymorphisms (SNPs) on FCA A1, D1, D2 and D3. The genomic regions harboring these SNPs contain 55 genes, of which 3 are associated with amyloidosis in humans or mice. One of these genes is SAA1, which encodes for a member of the Serum Amyloid A family, the precursor protein of Amyloid A, and a mutation in the promotor of this gene causes hereditary AA-amyloidosis in humans. These results provide novel knowledge regarding the complex genetic background of hereditary AA-amyloidosis in Siamese/Oriental cats and, therefore, contribute to future genomic studies of this disease in cats.

Patisiran Treatment in Patients with Transthyretin Cardiac Amyloidosis.

BACKGROUND: Transthyretin amyloidosis, also called ATTR amyloidosis, is associated with accumulation of ATTR amyloid deposits in the heart and commonly manifests as progressive cardiomyopathy. Patisiran, an RNA interference therapeutic agent, inhibits the production of hepatic transthyretin. METHODS: In this phase 3, double-blind, randomized trial, we assigned patients with hereditary, also known as variant, or wild-type ATTR cardiac amyloidosis, in a 1:1 ratio, to receive patisiran (0.3 mg per kilogram of body weight) or placebo once every 3 weeks for 12 months. A hierarchical procedure was used to test the primary and three secondary end points. The primary end point was the change from baseline in the distance covered on the 6-minute walk test at 12 months. The first secondary end point was the change from baseline to month 12 in the Kansas City Cardiomyopathy Questionnaire-Overall Summary (KCCQ-OS) score (with higher scores indicating better health status). The second secondary end point was a composite of death from any cause, cardiovascular events, and change from baseline in the 6-minute walk test distance over 12 months. The third secondary end point was a composite of death from any cause, hospitalizations for any cause, and urgent heart failure visits over 12 months. RESULTS: A total of 360 patients were randomly assigned to receive patisiran (181 patients) or placebo (179 patients). At month 12, the decline in the 6-minute walk distance was lower in the patisiran group than in the placebo group (Hodges-Lehmann estimate of median difference, 14.69 m; 95% confidence interval [CI], 0.69 to 28.69; P = 0.02); the KCCQ-OS score increased in the patisiran group and declined in the placebo group (least-squares mean difference, 3.7 points; 95% CI, 0.2 to 7.2; P = 0.04). Significant benefits were not observed for the second secondary end point. Infusion-related reactions, arthralgia, and muscle spasms occurred more often among patients in the patisiran group than among those in the placebo group. CONCLUSIONS: In this trial, administration of patisiran over a period of 12 months resulted in preserved functional capacity in patients with ATTR cardiac amyloidosis. (Funded by Alnylam Pharmaceuticals; APOLLO-B ClinicalTrials.gov number, NCT03997383.).

Evaluation of Psychopathologies and Health-Related Quality of Life in Patients With Macular Amyloidosis. / [Artículo traducido] Evaluación de psicopatologías y calidad de vida relacionada con la salud en pacientes con amiloidosis macular.

Macular amyloidosis (MA) is a skin condition with predominance in young women. We aimed to evaluate quality of life (QoL) and psychopathologies in these patients. In this cross-sectional study, patients with MA referring to the Imam Reza Hospital, Mashhad during 2018-2020, and their matched controls were included. Participants completed the 36-item short form survey (SF-36), the revised symptom checklist-90 (SCL-90-R), and the dermatology life quality index (DLQI). Overall, 40 women with a mean age of 36.80±10.19 years were studied. In the MA group, the SF-36 score was lower (P<0.001), and the SCL-90-R score was higher (P<0.001). The DLQI score was correlated with age (r=0.447; P=0.048) and pruritus severity (r=0.776; P<0.001), and was lower in patients with uncovered lesions (P=0.005). MA was associated with impaired QoL, which was determined by pruritus severity and lesion location; these patients can benefit from psychiatric interventions in this regard.

Localized Cutaneous Nodular Amyloidosis in a Patient with Sjögren's Syndrome.

Primary localized cutaneous nodular amyloidosis (PLCNA) is included in the primary forms of cutaneous amyloidosis along with macular and lichenoid amyloidosis. It is a rare disease attributed to plasma cell proliferation and deposition of immunoglobulin light chains in the skin. We present the case of a 75-year-old woman with a personal history of Sjogren's syndrome (SjS), who consulted for asymptomatic yellowish, waxy nodules on the left leg. Dermoscopy of the lesions showed a smooth, structureless, yellowish surface with hemorrhagic areas and few telangiectatic vessels. Histopathology revealed an atrophic epidermis and deposits of amorphous eosinophilic material in the dermis with a positive Congo red stain. The diagnosis of nodular amyloidosis was made. Periodic reevaluation was indicated after the exclusion of systemic amyloidosis. PLCNA is often associated with autoimmune connective tissue diseases, and up to 25% of all PLCNA cases occur in patients with SjS. Therefore, in addition to ruling out systemic amyloidosis, screening for possible underlying SjS should be performed when the diagnosis of PLCNA is confirmed.

Evaluation of Psychopathologies and Health-Related Quality of Life in Patients With Macular Amyloidosis.

Macular amyloidosis (MA) is a skin condition with predominance in young women. We aimed to evaluate quality of life (QoL) and psychopathologies in these patients. In this cross-sectional study, patients with MA referring to the Imam Reza Hospital, Mashhad during 2018-2020, and their matched controls were included. Participants completed the 36-item short form survey (SF-36), the revised symptom checklist-90 (SCL-90-R), and the dermatology life quality index (DLQI). Overall, 40 women with a mean age of 36.80±10.19 years were studied. In the MA group, the SF-36 score was lower (P<0.001), and the SCL-90-R score was higher (P<0.001). The DLQI score was correlated with age (r=0.447; P=0.048) and pruritus severity (r=0.776; P<0.001), and was lower in patients with uncovered lesions (P=0.005). MA was associated with impaired QoL, which was determined by pruritus severity and lesion location; these patients can benefit from psychiatric interventions in this regard.

Natural history and survival rate of familial amyloidosis with polyneuropathy: A nationwide databank.

OBJECTIVE: Hereditary amyloid transthyretin (ATTRv) amyloidosis with polyneuropathy, a rare autosomal-dominant disease, has gained attention in recent years owing to treatment improvements. However, epidemiological real-world mega database of nationwide natural history and survival rates, especially with the specific mutation of Ala97Ser, are limited. METHODS: Taiwan National Health Insurance Research Database contains data from over 23 million individuals; Among them, 175 ATTRv amyloidosis patients validated by rare disease registry were enrolled. Multivariable Cox proportional hazard analyses were applied to investigate the association between baseline characteristics and all-cause mortality. FINDINGS: From 2008 to 2020, the annual incidence and prevalence rates of specific mutations (Ala97Ser) leading to ATTRv amyloidosis with polyneuropathy were 0.04-1.14 and 0.04-4.79 per million in Taiwan, respectively. In Taiwan, these patients exhibited male predominance with a mean age at validation of 62.75 years. At the 5th year after validation, patients exhibited a survival rate of approximately 50%, with higher mortality in male patients (hazard ratio [HR]: 2.22, 95% confidence interval [CI]: 1.15-4.31) and patients older at validation (HR: 1.10, 95% CI: 1.06-1.15). The two most common departments in outpatient were neurology and family medicine, and neurology and cardiology in inpatient. The three most common causes of death registered were unspecified amyloidosis (30.6%), organ-limited amyloidosis (20.9%), and neuropathic heredofamilial amyloidosis (9.7%). INTERPRETATION: The annual prevalence rate of specific mutation (Ala97Ser)-dominant ATTRv amyloidosis with polyneuropathy in Taiwan is comparable to the mid- to high-prevalence country level of the research by Schmidt et al. The extraordinarily high mortality, especially among patients older at validation, may reflect the inadequate awareness and the necessity of early intervention with novel disease-modifying regimens.

AHNAK, regulated by the OSM/OSMR signaling, involved in the development of primary localized cutaneous amyloidosis.

BACKGROUND: Primary localized cutaneous amyloidosis (PLCA) is a chronic skin disease characterized by aberrant keratinocyte differentiation, epidermal hyperproliferation, and amyloid deposits. Previously, we demonstrated OSMR loss-function mutants enhanced basal keratinocyte differentiation through the OSMR/STAT5/KLF7 signaling in PLCA patients. OBJECTIVE: To investigate the underlying mechanisms involved in basal keratinocyte proliferation in PLCA patients that remain unclear. METHODS: Patients with pathologically confirmed PLCA visiting the dermatologic outpatient clinic were involved in the study. Laser capture microdissection and mass spectrometry analysis, gene-edited mice, 3D human epidermis culture, flow cytometry, western blot, qRT-PCR and RNA sequencing were used to explore the underlying molecular mechanisms. RESULTS: In this study, we found that AHNAK peptide fragments were enriched in the lesions of PLCA patients, as detected by laser capture microdissection and mass spectrometry analysis. The upregulated expression of AHNAK was further confirmed using immunohistochemical staining. qRT-PCR and flow cytometry revealed that pre-treatment with OSM can inhibit AHNAK expression in HaCaT cells, NHEKs, and 3D human skin models, but OSMR knockout or OSMR mutations abolished this down-regulation trend. Similar results were obtained in wild-type and OSMR knockout mice. More importantly, EdU incorporation and FACS assays demonstrated the knockdown of AHNAK could induce G1 phase cell cycle arrest and inhibit keratinocyte proliferation. Furthermore, RNA sequencing revealed that AHNAK knockdown regulated keratinocyte differentiation. CONCLUSION: Taken together, these data indicated that the elevated expression of AHNAK by OSMR mutations led to hyperproliferation and overdifferentiation of keratinocytes, and the discovered mechanism might provide insights into potential therapeutic targets for PLCA.