跳轉到

Q1. Which clinical presentations should be considered AL amyloidosis?

  • (A) Nephrotic-range proteinuria with any serum creatinine level.
  • (B) Infiltrative cardiomyopathy or heart failure with preserved ejection fraction.
  • (C) Hepatomegaly or alkaline phosphatase elevation without specific imaging abnormalities.
  • (D) A mixed axonal demyelinating peripheral neuropathy, sensory and/or motor and/or autonomic, particularly when associated with a monoclonal gammopathy.
  • (E) All of above.
點此顯示正解

(E) All of above.

詳解

1) Why (E) matches the stem framing:

The stem asks "Which clinical presentations should be considered AL amyloidosis?" — this is asking for TRUE statements about presentations that warrant consideration of AL amyloidosis. Option (E) "All of above" is the correct answer because each of options A through D represents a well-recognized clinical presentation that should prompt evaluation for AL amyloidosis13[4][10][^13].

2) Why each of the other options is also TRUE (and therefore supports "All of above"):

(A) Nephrotic-range proteinuria with any serum creatinine level — TRUE presentation to consider AL amyloidosis

The kidneys are affected in 60-70% of AL amyloidosis patients, typically manifesting as nephrotic-range proteinuria with hypoalbuminemia, secondary hyperlipidemia, and edema1[^10]. AL amyloidosis should be considered in any patient with proteinuria without obvious explanations such as longstanding hypertension or diabetes3[^12]. Importantly, kidney failure can occur even in the absence of proteinuria due to interstitial or vascular amyloid deposition1[^10], and the statement correctly notes "any serum creatinine level" — renal AL amyloidosis can present with preserved or impaired renal function.

(B) Infiltrative cardiomyopathy or heart failure with preserved ejection fraction — TRUE presentation to consider AL amyloidosis

The heart is involved in 70-80% of AL amyloidosis patients and is the leading cause of death1[^10]. Cardiac AL amyloidosis presents with diastolic dysfunction, restriction to ventricular filling, and concentric ventricular thickening on echocardiography3[^12]. Because dysfunction is primarily diastolic, systolic ejection fraction remains normal until late in the disease, making it a classic form of heart failure with preserved ejection fraction (HFpEF)3[^12]. The 2023 ACC Expert Consensus emphasizes that restrictive cardiomyopathy is one of the two most frequent manifestations of systemic AL amyloidosis2[^11].

(C) Hepatomegaly or alkaline phosphatase elevation without specific imaging abnormalities — TRUE presentation to consider AL amyloidosis

Liver involvement occurs in approximately 20% of AL amyloidosis patients and causes cholestasis and hepatomegaly1[10][13]. Critically, patients with hepatomegaly with no imaging abnormalities and an elevated alkaline phosphatase should have amyloidosis included in the differential diagnosis[4][13]. This presentation is specifically highlighted as a red flag because the hepatomegaly is due to amyloid infiltration rather than structural lesions visible on conventional imaging.

(D) A mixed axonal demyelinating peripheral neuropathy, sensory and/or motor and/or autonomic, particularly when associated with a monoclonal gammopathy — TRUE presentation to consider AL amyloidosis

Nervous system involvement occurs in approximately 22% of AL amyloidosis patients[4][13]. Patients with symmetric neuropathy affecting the longest nerves (lower legs and feet), sensory or mixed sensory-motor neuropathy characterized by numbness, paresthesias, and dysesthesias — particularly those with an associated monoclonal protein, autonomic dysfunction, or bilateral carpal tunnel syndrome — are candidates for amyloidosis screening[4][5][^13]. AL amyloidosis causes small-fiber neuropathy and autonomic dysfunction manifested as gastrointestinal motility disturbances, orthostatic hypotension, and neurogenic bladder1[^10].

詳解 · 中文翻譯

1) 為什麼 (E) 符合題幹框架：

題幹要求「哪些臨床呈現應考慮 AL 澱粉樣變？」— 這要求正確的關於應提示評估 AL 澱粉樣變的呈現的敘述。選項 (E)「上述所有」 是正確答案，因為選項 A 至 D 中的每一個代表應提示評估 AL 澱粉樣變的公認臨床呈現13[4][10][^13]。

2) 為什麼其他每個選項也是正確的（因此支持「上述所有」）：

(A) 任何血清肌酐水平的尿蛋白綜合征範圍尿蛋白 — 應考慮 AL 澱粉樣變的正確呈現

腎臟在 60-70% 的 AL 澱粉樣變患者中受影響，通常表現為尿蛋白綜合征範圍尿蛋白，伴隨白蛋白血症、繼發性高脂血症和水腫1[^10]。應在任何患有沒有明顯解釋的尿蛋白患者中考慮 AL 澱粉樣變，如長期高血壓或糖尿病3[12]。重要地是，由於間質或血管澱粉樣沉澱，即使在沒有尿蛋白的情況下腎功能衰竭也可能發生1[10]，敘述正確注意到「任何血清肌酐水平」— 腎 AL 澱粉樣變可能以保留或受損的腎功能呈現。

(B) 浸潤性心肌病或保留射血分數的心衰 — 應考慮 AL 澱粉樣變的正確呈現

心臟在 70-80% 的 AL 澱粉樣變患者中受影響，是死亡的主要原因1[^10]。心臟 AL 澱粉樣變呈現舒張功能障礙、心室充盈限制和超聲心動圖上的同心室增厚3[^12]。因為功能主要是舒張期的，收縮射血分數直到疾病晚期仍保持正常，使其成為保留射血分數心衰 (HFpEF) 的經典形式3[^12]。2023 ACC 專家共識強調限制性心肌病是全身 AL 澱粉樣變的兩個最頻繁表現之一2[^11]。

(C) 沒有特定影像異常的肝腫大或鹼性磷酸酶升高 — 應考慮 AL 澱粉樣變的正確呈現

肝臟在約 20% 的 AL 澱粉樣變患者中受累，導致膽汁淤積和肝腫大1[10][13]。關鍵地，患有沒有影像異常和鹼性磷酸酶升高的肝腫大患者應將澱粉樣變包括在鑑別診斷中[4][13]。此呈現特別強調為紅旗，因為肝腫大是由澱粉樣沉澱導致的，而不是在常規影像上可見的結構性病變。

(D) 混合軸索脫髓鞘周邊神經病，感覺和/或運動和/或自主，特別是當與單克隆球蛋白相關時 — 應考慮 AL 澱粉樣變的正確呈現

神經系統在約 22% 的 AL 澱粉樣變患者中受累[4][13]。患有影響最長神經（下腿和腳）的對稱神經病、感覺或混合感覺-運動神經病，特徵為麻木、異常感覺和異常疼痛感 — 特別是那些伴隨相關單克隆蛋白、自主功能障礙或雙側腕隧道綜合症的 — 是澱粉樣變篩查的候選[4][5][^13]。AL 澱粉樣變導致小纖維神經病和自主功能障礙表現為胃腸蠕動障礙、直立性低血壓和神經源性膀胱1[^10]。

參考文獻 (AMA)

  1. Sanchorawala V. Systemic Light Chain Amyloidosis. The New England Journal of Medicine. 2024;390(24):2295-2307. doi:10.1056/NEJMra2304088. PMID:38924733. ↩↩↩↩↩↩↩↩↩↩↩↩

  2. Gertz MA, Dispenzieri A. Systemic Amyloidosis Recognition, Prognosis, and Therapy: A Systematic Review. Jama. 2020;324(1):79-89. doi:10.1001/jama.2020.5493. PMID:32633805. ↩↩

  3. Kittleson MM, Ruberg FL, Ambardekar AV, et al. 2023 ACC Expert Consensus Decision Pathway on Comprehensive Multidisciplinary Care for the Patient With Cardiac Amyloidosis: A Report of the American College of Cardiology Solution Set Oversight Committee. Journal of the American College of Cardiology. 2023;81(11):1076-1126. doi:10.1016/j.jacc.2022.11.022. PMID:36697326. ↩↩↩↩↩↩↩↩

Figures