台灣多發性骨髓瘤的研究─流行病學，細胞遺傳學，分子細胞遺傳學和動物模式

Abstract

本論文集是台灣地區，也可能是亞洲地區，首次對人類多發性骨髓瘤做有系統的研究。內容主要包含三個部份：其ㄧ是台灣地區過去二十多年多發性骨髓瘤的流行病學資料；其二是台灣地區多發性骨髓瘤的腫瘤染色體基因變化和臨床應用；其三是嘗試開發新的人鼠嵌合動物模式應用在未來多發性骨髓瘤的研究上。

由流行病學的研究我們得知過去二十多年來台灣地區多發性骨髓瘤的發生率和死亡率都是持續上升。民國六十八年和九十年的粗發生率分別是每十萬人口中0.16人和1.29人。這段時間平均的粗發生率則為每十萬人口中0.59人。若採用世衛組織發佈的世界標準人口(1976年和2000年)來做年齡的標準化，則這段時間平均的年齡標準化後發生率分別為每十萬人口中0.61人和0.65人。相同年齡標準化後平均死亡率則分別為每十萬人口中0.49人和0.55人。多發性骨髓瘤好發在男性，男女發生率的比例是1.68:1。骨髓瘤最好發在七十歲的年齡層，四十歲以下的發生率很低。本院歷來多發性骨髓瘤病人的臨床特徵以及傳統化學治療的成績與西方國家相仿，平均存活時間為28個月，十年以上的存活機率僅7.3%。死因則大多是肺炎及敗血症。從事農業工作者與罹患多發性骨髓瘤似乎有相關。比較年輕的病人似乎比較會有髓外病灶的表現，其機轉值得後續研究。

我們利用傳統染色體研究方法觀察骨髓瘤細胞分裂時候有何染色體的變化，發現有變化的比例為29.4%。其變化大多是複雜的。染色體數目是多套體的比例大概是43.2%，非多套體則是56.8%，這兩者在臨床表現及預後上有顯著差別。比較多的染色體變化是第9、15對染色體呈現三倍體，第13對染色體呈現單倍體，1q的複製和14q32的重組。用去氧核醣核酸螢光原位雜交法來偵測細胞染色體特定基因的變化與傳統方法正好可以互補，且針對第13對染色體的缺失可以將病人分成三個不同預後的族群，所以合併此兩法極具臨床預後的價值。我們新發現的add(19)(p13)染色體變化可能是骨髓瘤的特殊亞型，值得後續研究。

我們嘗試用人類胎兒骨植入一種新的免疫不全鼷鼠 (non-obese & non-diabetic, NOD/SCID)的皮下來表現人類多發性骨髓瘤的臨床特性。結果這種模式相當成功地表現出骨髓瘤漿細胞增生，腫瘤免疫球蛋白的上升和蝕骨病變。接種成功率高達90%以上。另有61%會長出胎兒骨膜上的巨大腫瘤，這些腫瘤可以繼續轉殖下去。經由細胞表面標記檢定，染色體檢查和免疫球蛋白基因上核苷酸序列的分析，這些被轉殖的腫瘤與原始的骨髓瘤細胞相當類似。這種新的動物模式除了表現骨髓瘤的臨床特性外，有別於過去細胞株的培養模式，也可以做為一種生物活體培養系統，提供未來研究骨髓瘤的材料和從事對照實驗的機會。

This is the first time that serial studies on multiple myeloma (MM) conducted in Taiwan. There are three components in the thesis: epidemiology of MM in Taiwan for the past two decades, conventional cytogenetics and fluorescence in-situ hybridization analyses on our MM patients and a new nod-SCID/human chimeric animal model for MM. From the descriptive epidemiological study on MM in Taiwan, it is known that the incidence and mortality rates of MM keep increasing for the past two decades. The crude incidence rates per 100,000 persons of MM were 0.16 in 1979 and 1.29 in 2001. The average age-adjusted (1976 and 2000 world population) incidence rates of MM in Taiwan for 1979-2001 were 0.61 and 0.65 per 100,000 persons, respectively. The average age-adjusted (1976 and 2000 world population) mortality rates of MM were 0.49 and 0.55 per 100,000 persons, respectively. The average male-to-female incidence ratio was 1.68:1. The incidence of MM peaked at the seventh decade. Of the hospital MM patients, the clinical characteristics and treatment outcome were similar to western countries. The overall survival, 10-year survival were 28 months and 7.3%, respectively. Agriculture was likely to associate with occurrence of MM. Higher incidence of extramedullary MM in younger patients were noted. Cytogenetic anomalies (CA) were detected by conventional cytogenetics (CG) (CG_CA) in 44 (29.3%) of the 150 patients and by FISH (FISH_CA) in 59 (67.0%) of the 88 studied patients. Presence of either CG_CA or FISH_CA was associated with a poor prognosis. Patients with CG_CA and hyperdiploid chromosomes, always associated with several trisomies, had a longer survival in comparison to those with non-hyperdiploid chromosomes, usually associated with a monosomy 13/partial deletion of 13q (Δ13) and a rearrangement of 14q32. A novel recurrent CG_CA, add (19)(p13), was found in four patients; all males with immunoglobulin G/λ isotypes, extramedullary myeloma at diagnosis, and a poor prognosis. Three groups of patients with significantly different survival, CG_Δ13, FISH_Δ13 but without CG_Δ13, and neither CG_Δ13 nor FISH_Δ13 were identified. The NOD/SCID human chimeric animal model was generated by implanting of human fetal bones (FBs) into subcutaneous sites of NOD/SCID mice, followed by inoculation of primary bone marrow mononuclear cells obtained from patients with MM into the FBs. Most of them revealed evidence of tumor growth of myeloma cells in the NOD/SCID-hu+ mice and some would develope not only myeloma in the BM of the FBs, but also extramedullary macro-tumors (EMTs) along the periosteum of the FBs. The tumor cells in these EMTs had plasmacytoid morphology and preserved antigens and cytogenetics similar, if not identical, to those in the parent MCs. The NOD/SCID-hu chimeric animal model is highly efficient for growth of primary MCs and presents clinical features of human MM. The engrafted MCs can be maintained subsequently in NOD/SCID-hu- mice as in vivo culture.