CD56阳性伴特异髓系抗原表达的白血病5例临床和预后分析

Clinical and Prognostic Features of Leukemia with positive CD56 and specific myeloid-associated antigens in Five Pediatric Patients

目的 CD56阳性并伴特异髓系抗原表达的白血病在儿童罕见,但有独特的临床特点及预后,有人认为可能来源于非成熟自然杀伤(NK)细胞,但备受争议,分析其临床过程有助于加深认识。方法白血病患儿有以下特征者纳入分析:骨髓幼稚细胞细胞化学染色过氧化酶阴性(MPO-)伴免疫表型CD56+CD3-CD7+CD34+和髓系抗原+,或细胞化学MPO+伴CD56+CD3-HLA-DR-和髓系抗原+。根据文献前者被认为可能是髓系/NK前体细胞急性白血病(MNKPL),后者可能是髓系/NK细胞急性白血病(MNKL)。治疗采用高危急性淋巴细胞白血病方案,含阿糖胞苷、米托蒽醌、依托泊苷、门冬酰胺酶和甲氨蝶呤等。结果 2005-2008年,5例1～8岁男性患儿具有上述特征,4例符合MNKPL,1例符合MNKL。符合MNKPL的4例并无成人患者常见的明显髓外浸润,但有骨髓活检的2例见明显骨髓纤维化。该4例对治疗反应极其缓慢,至今3例已持续缓解20～57个月,1例死于缓解期肺炎。结论有CD56+并伴特异髓系抗原表达的儿童白血病其临床特征可能异于成人患者,用含有用于髓系和淋系白血病化疗药物的治疗方案,可能有助于改善MNKPL的预后。

Objective Leukemia with positive CD56 and specific myeloid-associated antigens was rare in childhood, which had distinct clinical characteristics and prognosis. Someone considered that it was derived from immature nature killer （NK） cells but was highly controversial. Analysis on its clinical features would promote better understanding. Methods Leukemic children with MPO-, CD56 ＋ CD3 - CD7 ＋ CD34＋ and myeloid antigens＋ were diagnosed as myeloid/NK-cell precursor acute leukemia （MNKPL）. Leukemic children with MPO＋, CD56＋ CD3-HLA-DR- and myeloid antigens＋ were diagnosed as myeloid/NK cell acute leukemia （MNKL）. They were treated with high-risk childhood acute lymphoblastic leukemia （AIL） regimen containing cytarabine, mitoxantrone, eptoposide, L-asparaginase and methotrexate. Results Five children aged 1-8 years were treated from 2005 to 2008, 4 of them were MNKPL and 1 was MNKL. In children with MNKPL, there was no extramedullary involvement. However, myelofibrosis was found in 2 children. The therapeutic reaction to chemotherapy was extremely slow. Three children gotcontinuous complete remission （CR） for 20-57 months except one child who died of pneumonia in CR stage. Conclusion Childhood leukemia with positive CD56 and specific myeloid-associated antigens may have different characteristics with those in adult patients. Therapeutic regimen used for acute myeloid leukemia and ALL may be effective for improving the prognosis of MNKPL.