342例成人系统性肥大细胞增多症患者：生存和预后因素研究

根据卫生组织（WHO）的诊疗标准将系统性肥大细胞增多症分为4个亚型，1976年到2007年间我们在梅奥诊所确诊了159例（46%）静止性全身性肥大细胞增生症，138（40%）例伴随其它血液细胞增生之全身性肥大细胞增生症，41（12%）例侵犯性全身性肥大细胞增生症，4（1%）例肥大细胞白血病。我们提取骨髓组织的DNA通过等位基因特异性PCR可以检测出kitD816V基因（皮肤以外器官的肥大细胞出现位于codon816位置的kit基因突变），在165患者中68%的患者通过此法被确诊（静止性全身性肥大细胞增生症占78%，侵犯性全身性肥大细胞增生症占82%，伴随其它血液细胞增生之全身性肥大细胞增生症占60%;p=0.03）;4%的伴随其它血液细胞增生之全身性肥大细胞增生症患者可检测出JAK2V617F基因突变。与伴随其它血液细胞增生之全身性肥大细胞增生症患者的预期寿命相比较，静止性全身性肥大细胞增生症患者的预期寿命较长，并且这类患者的寿命与年龄性别相匹配的美国人无明显差别。此外，多因素分析表明高龄、体重的减低、贫血、血小板减少、低蛋白血症和过量的骨髓细胞充盈是导致预后较差的主要因素。本研究表明系统性肥大细胞增多症的亚型与预后密切相关，为我们提供了与危险分层有关的更多宝贵信息，对临床表现和实验室检查结果亦进行了良好的解释。

专家评价：MarcusMaurerwithKarstenWellerCharité-Universit?tsmedizinBerlin,GermanyDermatologyInthisimportant,anduptonowlargest,studyonsystemicmastocytosis（SM）,markeddifferencesintheprognosisofsubgroupsaredemonstratedandriskfactorsforshortersurvivalareidentified.Atherapyadaptedtothesubgroupofmastocytosisissuggested.SMisararedisease.ThatiswhydetaileddataontheprognosisofSM,itssubformsandapossibleprogressionfromindolenttoaggressivediseaseislargelymissing.ThepresentstudyfromLimandcolleaguesisthe,uptonow,largeststudyinthefieldofSM.Theauthorsdescribetheclinical,laboratoryandbonemarrowhistologicfeaturesatpresentationinalargecohortofadultpatients.TheydemonstratethatthesurvivalofallpatientswithSMisshorterascomparedtoanage-andgender-matchedcontrolpopulationandthatdifferentsubgroupsofSM（indolentSM,aggressiveSM,SMwithassociatedclonalhematologicalnon-mastcelllineagedisease（AHNMD）,mastcellleukemia）exhibitsignificantdifferencesindiseasecharacteristics.Forexample,andmostinterestingly,theyfoundthatpatientswithindolentSMhaveanormallifeexpectancy.Incontrast,allotherSMsubgroupshaveamuchpoorerprognosis.Inaddition,theauthorsidentifyadditionalriskfactorsassociatedwithshortersurvival（advancedage,weightloss,anemia,thrombocytopenia,hypoalbuminemiaandexcessbonemarrowblasts）.Thisstudyisofmajorimportance,becausethedataclearlyconfirmsthatpatientswithindolentSMcanbecalmeddownwhengettingtheirdiagnosis.Moreover,thedatasubstantiatesthepracticethattherapyofpatientswithindolentSMshouldbeprimarilysymptomdirectedandnotaggressiveandpotentiallyharmful.Incontrast,othersubgroupsseemtorequireamoreaggressiveregimen.Thefact,thattheauthorsdescribesomepatientswithaprogressionfromindolentinaggressiveSMormastcellleukemiaandtheriskofanAHNMDmakesitreasonabletoexaminethepatientsregularly.Inaddition,anequipmentofpatientswithemergencykitsseemstobeadvisable,becausetheauthorsreporttwodeathsduetocomplicationsfrommassivemastcellmediatorrelease.Thestrengthofthispublicationisthelargenumbersofpatientsincludedandtheelaboratenessoftheevaluations.Onemajorweaknesslaysinthefactthatthedatawascollectedinatertiarycarecenter.Moreover,itisaretrospectivestudyandonemainfocusoftheauthorsishematology.Therefore,anextrapolationtothe‘general’SMpopulationmaynotbevalid.Theauthorsstatethislimitationbythemselves.Inourexperience,derivedfromadermatologyoutpatientdepartment,muchfewerpatientspresentwithordevelopaggressiveSMoranAHNMD.