Systemic amyloidosis journey from diagnosis to outcomes: a twelve-year real-world experience of a single center in a middle-income country

BACKGROUND

Systemic amyloidosis is caused by the deposition of misfolded protein aggregates in tissues, leading to progressive organ dysfunction and death. Epidemiological studies originate predominantly from high-income countries, with few data from Latin America. Due to the non-specific clinical manifestations, diagnosing amyloidosis is often challenging and patients experience a long journey and delay in diagnosis. This study aimed to assess clinical and laboratory characteristics, the diagnostic journey, and outcomes of patients with biopsy-proven systemic amyloidosis diagnosed between 2009 and 2020 at a university referral center in a middle-income Latin American country. Patients´ medical records were retrospectively reviewed.

RESULTS

One hundred and forty-three patients were included. The median age at diagnosis was 60 years and 54% were male. Until the diagnosis, most of the patients (52%) were seen by at least 3 specialists, the main ones being: general practitioners (57%), nephrologists (45%), and cardiologists (38%). The most common manifestations were renal (54%) and cardiac (41%) disorders, and cachexia was seen in 36% of patients. In 72% of the cases, ≥ 2 biopsies were required until the final diagnosis. The median time from symptoms onset to diagnosis was 10.9 months, and most patients (75%) had ≥ 2 organs involved. The following subtypes were identified: AL (68%), ATTR (13%), AA (8%), AFib (4%), and inconclusive (7%). Median OS was 74.3 months in the non-AL subgroup and 18.5 months in AL. Among AL patients, those with advanced cardiac stage had the worst outcome [median OS 8.6 months versus 52.3 for stage III versus I-II, respectively (p < 0.001)]. AL subtype, cardiac involvement, and ECOG ≥ 2 were identified as independent risk factors for reduced survival.

CONCLUSIONS

Systemic amyloidosis is still an underdiagnosed condition and the delay in its recognition leads to poor outcomes. Medical education, better diagnostic tools, improvement in access to therapies, and establishment of referral centers may improve patient outcomes in middle-income countries.

Perfil Clínico, Laboratorial e de Métodos de Imagem na Amiloidose Sistêmica em um Centro de Referência Cardiológico Brasileiro

Fundamento

Amiloidose sistêmica é uma doença com manifestações clínicas diversas. O diagnóstico envolve suspeita clínica, aliada a métodos complementares.

Objetivo

Descrever o perfil clínico, laboratorial, eletrocardiográfico e de imagem no acometimento cardíaco da amiloidose sistêmica.

Métodos

Estudo de uma amostra de conveniência, analisando dados clínicos, laboratoriais, eletrocardiográficos, ecocardiográficos, medicina nuclear e ressonância magnética. Considerou-se significância estatística quando p < 0,05.

Resultados

Avaliaram-se 105 pacientes (com mediana de idade de 66 anos), sendo 62 homens, dos quais 83 indivíduos apresentavam amiloidose por transtirretina (ATTR) e 22 amiloidose por cadeia leve (AL). Na ATTR, 68,7% eram de caráter hereditário (ATTRh) e 31,3% do tipo selvagem (ATTRw). As mutações mais prevalentes foram Val142Ile (45,6%) e Val50Met (40,3%). O tempo de início dos sintomas ao diagnóstico foi 0,54 e 2,15 anos nas formas AL e ATTR (p < 0,001), respectivamente. O acometimento cardíaco foi observado em 77,9% dos ATTR e 90,9% dos AL. Observaram-se alterações de condução atrioventricular em 20% e intraventricular em 27,6% dos pacientes, sendo 33,7 % na ATTR e 4,5% das AL (p = 0,006). A forma ATTRw apresentou mais arritmias atriais que os ATTRh (61,5% x 22,8%; p = 0,001). Ao ecocardiograma a mediana da espessura do septo na ATTRw x ATTRh x AL foi de 15 mm x 12 mm x 11 mm (p = 0,193). Observou-se BNP elevado em 89,5% dos indivíduos (mediana 249 ng/mL, IQR 597,7) e elevação da troponina em 43,2%.

Conclusão

Foi possível caracterizar, em nosso meio, o acometimento cardíaco na amiloidose sistêmica, em seus diferentes subtipos, através da história clínica e dos métodos diagnósticos descritos.

Preservation of platelet function in patients with cirrhosis and thrombocytopenia undergoing esophageal variceal ligation

BACKGROUND

Thrombocytopenia is a possible risk factor for bleeding after band ligation of esophageal varices. However, elevated von Willebrand factor (VWF) in cirrhosis improves platelet function and could decrease this risk. Our objective was to assess platelet function in patients with cirrhosis undergoing esophageal variceal ligation (EVL).

METHODS

The assessment consisted of platelet count, antigen and activity of VWF and VWF-cleaving protease ADAMTS-13 activity, and a platelet adhesion and aggregation test simulating vascular flow in vivo (Impact-R^Ⓡ) prior to EVL.

RESULTS

Totally 111 patients were divided into three groups according to platelet count: (1) < 50 × 10⁹/L (n = 38, 34.2%); (2) 50 × 10⁹/L to 100 × 10⁹/L (n = 47, 42.3%); and (3) > 100 × 10⁹/L (n = 26, 23.4%). No statistically significant difference was found in the aggregate size of platelets [group 1: 41.0 (31.8-67.3) µm²; group 2: 47.0 (33.8-71.3) µm²; and group 3: 47.0 (34.0-66.0) µm²; P = 0.60] and no significant correlation was found between aggregate size and platelet count (Spearman r = 0.07; P = 0.47). Surface coverage was 4.1% (2.8%-6.7%), 8.5% (4.0%-10.0%), and 9.0% (7.1%-12.0%) (P < 0.001) in groups 1, 2 and 3, respectively and correlated with platelet count (Spearman r = 0.39; P < 0.0001). There was no significant difference between groups in VWF or ADAMTS-13. Post-EVL bleeding occurred in six (5.4%) patients (n = 2 in group 1, n = 1 in group 2, and n = 3 in group 3; P = 0.32). Patients with bleeding had higher MELD scores [15.0 (11.3-20.3) versus 12.0 (10.0-15.0); P = 0.025], but no difference was demonstrated for platelet function parameters.

CONCLUSION

Platelet function is preserved even in the presence of thrombocytopenia, including in the patients with post-EVL bleeding.

Liver transplantation for subacute hepatocellular failure due to massive steatohepatitis after bariatric surgery

New therapeutic options for obesity include restrictive bowel surgery and surgery that promotes malabsorption, such as the Fobi-Capella (gastric bypass) and Scopinaro (biliopancreatic diversion) techniques. Complications associated with these procedures, such as hepatocellular failure, have been observed with increasing frequency. Reported here are 3 patients who, 7 to 24 months after bariatric surgery, developed hepatocellular failure, for which liver transplantation was considered to be indicated. Liver transplantation was undertaken in 2 of the patients; the third patient died while waiting for this procedure. We discuss the possible causes of this uncommon and poorly understood complication of surgery for obesity. One possibility is that it might arise as a result of progression of steatohepatitis. An alternative concept is that this complication may be secondary to rapid, massive loss of body weight.