弹性成像SR值、最大血流速度、TPOAb、TgAb应用于桥本氏甲状腺炎临床诊断的研究

目的:研究弹性成像应变率比值(SR)、最大血流速度、甲状腺过氧化物酶抗体(TPOAb)、甲状腺球蛋白抗体(TgAb)应用于桥本氏甲状腺炎的临床诊断.方法:选取我院收治的86例桥本氏甲状腺炎患者作为实验组,根据甲状腺功能分为甲亢组(n=32)、甲减组(n=25)以及单纯甲状腺肿组(n=29).并选取同期86例健康体检者作为对照组(n=86).所有入选者均接受弹性成像超声和血清学检查.对比实验组和健康组弹性成像超声指数和TPOAb、TgAb及促甲状腺激素(TSH)水平;对比不同甲状腺功能患者的SR值、最大血流速度和TPOAb、TgAb水平、TSH;分析SR值、最大血流速度和TPOAb、TgAb与TSH的相关性.结果:与对照组相比,实验组SR值显著降低,最大血流速度、TPOAb、TgAb和TSH显著增高(P<0.05).与单纯甲状腺肿组相比,甲亢组SR值和TSH水平显著更低,最大血流速度、TPOAb、TgAb和TSH显著更高,甲减组SR值显著更低,最大血流速度、TPOAb、TgAb和TSH显著更高(P<0.05);与甲减组相比,甲亢组患者SR值和TSH水平显著更低,最大血流速度、TPOAb、TgAb和TSH显著更高(P<0.05).结论:桥本氏甲状腺炎患者的SR值、最大血流速度TPOAb以及TgAb均存在明显的变化.患者在不同甲状腺功能中也存差异性,临床上可将SR值、最大血流速度TPOAb以及TgAb作为桥本氏甲状腺炎诊断的辅助方法.     

妊娠亚临床甲减患者血清TSH、TPO-AB水平与妊娠结局的相关性研究

目的探讨妊娠期合并亚临床甲状腺功能减退(亚甲减)患者血清促进甲状腺素(TSH),甲状腺过氧化物酶抗体(TPOAb)水平与妊娠结局的关系。方法选取2016年1月至2017年2月在我院定期接受产前检查、定期围产保健且住院分娩的亚甲减患者300例,根据有无接受治疗分为亚甲减治疗组(n=189)和亚甲减未治疗组(n=111);根据血清TSH中位数水平分为高TSH水平组(n=95)和低TSH水平组(n=205);并根据血清TPOAb检测是否为阳性分为TPOAb阳性组(n=182)与TPOAb阴性组(n=118)。另选取同期300例健康孕妇为对照组。对各组妊娠结局进行统计分析。结果亚甲减未治疗组流产、早产、GDM、妊娠期高血压疾病、胎儿生长受限、低出生体重儿发生率均明显高于亚甲减治疗组及对照组(P<0.05)。亚甲减孕妇中,高TSH水平组流产、早产、GDM、妊娠期高血压疾病、胎儿生长受限、低出生体重儿发生率均明显高于低TSH水平组(P<0.05);TPOAb阳性组流产、早产、GDM、妊娠期高血压疾病、低出生体重儿发生率均明显高于TPOAb阴性组(P<0.05)。结论妊娠合并亚甲减可增加流产、早产、GDM、妊娠期高血压疾病、胎儿生长受限、低出生体重儿发生率,且血清TSH水平越高及TPOAb阳性,不良妊娠结局风险越高。     

桥本氏甲状腺炎合并甲状腺癌TGAb、TPOAb、TSH水平及超声特征分析

目的:分析桥本氏甲状腺炎合并甲状腺癌抗甲状腺球蛋白抗体(Antithyroid globulin antibody,TGAb)、抗甲状腺过氧化物酶抗体(Anti thyroid peroxidase antibody,TPOAb)、促甲状腺素(Thyrotropin,TSH)水平及超声特征.方法:选取本院2013年4月至2020年11月收治的甲状腺癌患者中筛选出合并桥本氏甲状腺炎36例(研究组),未合并者58例(对照组);比较两组患者TGAb、TPOAb、TSH水平,观察其影像学特征.结果:研究组TGAb、TPOAb、TSH水平均高于对照组(P<0.05).彩色多普勒超声显示,研究组内部多无血流,对照组内部多有血流(P<0.05).结论:甲状腺癌合并桥本甲状腺炎的临床特征及超声表现与单纯的甲状腺癌具有一定差异,充分掌握了解其特征可为临床诊治提供依据.     

左旋甲状腺素片对TPOAb阳性复发性流产患者甲状腺功能及妊娠结局的影响

目的:探究伴甲状腺过氧化物酶抗体(Thyroid peroxidase antibody,TPOAb)阳性的复发性流产患者使用左旋甲状腺素片的效果及对母儿结局的影响。方法:采用抽签法将2016年9月至2018年3月在我科就诊85例有复发性流产史伴TPOAb阳性产妇随机分为2组,其中常规组患者42例,两组均采用达肝素钠50000 IU每次皮下注射、口服阿司匹林25 mg·次~(-1)、钙尔奇600 mg·次~(-1)、叶酸片0.4 mg·次~(-1),Qd等常规治疗,联合组43例患者在此基础上加服左旋甲状腺素片25μg·次~(-1),Qd,均用药至分娩结束(流产、早产或自然生产等),治疗前后清晨分别取两组患者周静脉血液,分离血清后,酶联免疫吸附法检测两组甲状腺过氧化物酶(Thyroid peroxidase,TPO)、游离甲状腺素(Free thyroxine,FT_4)及促甲状腺激素(Thyroid stimulating hormone,TSH)血清水平,其中治疗前两组上述指标水平差异无统计学意义(P0.05),对比治疗后两组上述指标水平及妊娠结局。结果:联合组治疗后胎膜早破、早产及TPO和TSH水平均低于常规组(P0.05);新生儿1 min及5 min评分、体重、身高及FT_4水平两组无统计学差异(P0.05)。结论:左旋甲状腺素片应用于复发性流产患者伴TPOAb阳性患者,可改善患者甲状腺功能,降低流产率,且对新生儿健康无影响。     

促甲状腺激素和甲状腺自身抗体在甲状腺疾病中的诊断价值分析

目的分析促甲状腺激素和甲状腺自身抗体在甲状腺疾病中的诊断价值。方法选取本院2018年6月至2019年3月收治的82例甲状腺疾病患者作为研究组,其中甲状腺机能减退症患者(甲减)29例、毒性弥漫性甲状腺病患者(GD)32例、桥本甲状腺炎患者(HT)21例。另外选择同期本院体检的30例健康者作为对照组。对所有研究对象的TSH、TRAb、TGAb以及TPOAb指标进行检测,汇总并观察不同疾病4种指标变化情况。结果 GD组、甲减组、HT组患者的TGAb、TPOAb血清水平明显高于对照组,差异具有统计学意义(P0.05);GD组患者TSH血清水平明显低于对照组,TRAb血清水平显著高于对照组(P0.05);甲减组患者TSH血清水平明显高于对照组,差异具有统计学意义(P0.05)。结论促甲状腺激素和甲状腺自身抗体可以一定程度反映患者甲状腺疾病情况,可为临床上提供诊断甲状腺疾病的原始资料,值得推广应用。     

水源性高碘地区健康人群甲状腺自身抗体阳性筛查分析

目的:探讨沧州市健康体检人群甲状腺自身抗体的阳性率及其与甲状腺功能异常的相关性。方法:采用电化学发光免疫分析技术测定沧州市3 218 名健康体检人群血清促甲状腺激素(TSH)、游离三碘甲腺原氨酸(FT3)、游离甲状腺素(FT4)、甲状腺过氧化物酶抗体(TPOAb)和甲状腺球蛋白抗体(TgAb),分别以TPOAb>34 U/ ml 和TgAb>115 U/ ml 为阳性,对检测结果进行统计分析。结果:健康人群甲状腺自身抗体的总阳性率为16.19%,且随年份增加呈明显的增高趋势,不同性别之间的阳性检出率有显著性差异(P <0.001),其中TPOAb、TgAb、TPOAb 和TgAb 同时阳性的检出率分别为14.57%、12.74%和11.12%,1 686 名女性的阳性检出率(21.53%、19.16%、16.67%)显著高于男性(6.92%、5.68%、5.03%),差异有统计学意义(P 均<0.001),且随年龄增加阳性检出率逐渐升高,女性阳性率高峰在逸70 岁年龄组,男性阳性率高峰在50 ~59岁年龄组。甲亢和亚甲亢、甲减和亚甲减甲状腺自身抗体的阳性检出率和OR 均有显著性差异(P<0.001)。结论:沧州市健康体检人群甲状腺自身抗体的阳性率较高,对甲状腺功能正常而自身抗体阳性者进行动态监测、随访或早期干预,有利于甲状腺疾病的早期诊断、鉴别诊断及其防治。     

自身免疫性甲状腺病伴甲状腺功能亢进的临床治疗分析

目的探讨分析自身免疫性甲状腺病(AITD)合并甲状腺功能亢进(简称甲亢)患者给予丙硫氧嘧啶片与泼尼松龙片联合治疗的临床效果。方法将我院近两年来收治的210例AITD合并甲亢患者按照随机数字表法分为观察组(给予丙硫氧嘧啶片与泼尼松龙片联合治疗)和对照组(单独给予丙硫氧嘧啶治疗),对比观察两组患者治疗前后游离三碘甲状腺原氨酸(FT3)、游离甲状腺素(FT4)、血清促甲状腺激素(TSH)、甲状腺球蛋白抗体(TGAb)、血清甲状腺过氧化酶抗体(TPOAb)等各项指标变化情况。结果两组患者治疗后FT3、FT4、TGAb、TPOAb等指标水平均有所下降,而TSH水平均有所上升,但观察组患者各项指标改善幅度显著优于对照组患者,差异性显著,具有统计学意义(P<0.05)。结论采用丙硫氧嘧啶与泼尼松龙联合治疗自身免疫性甲状腺病合并甲亢患者临床疗效佳,可显著改善患者功能相关指标,抑制免疫反应,促进患者甲状腺功能尽早恢复,值得在临床上进一步推广、应用。     

甲功五项联合TPOAb、TRAb检测在妊娠期妇女中的应用价值

目的 探究甲功五项联合甲状腺过氧化物酶抗体(TPOAb)、促甲状腺素受体抗体(TRAb)检测在妊娠期妇女中的应用价值.方法 选择2019年7月至2021年2月于我院孕检并分娩的104例孕妇,均进行甲状腺功能筛查,检测甲功五项血清三碘甲状腺氨酸(T3)、甲状腺素(T4)、游离T3(FT3)、游离T4(FT4)、促甲状腺素(TSH)和TPOAb、TRAb水平,分析检测结果及孕妇妊娠结局.结果 104例孕妇存在甲状腺功能异常的发生率为17.31％,TPOAb阳性率和TRAb阳性分别为15.38％、2.88％,妊娠早期、中期、晚期甲状腺功能异常发生率分别为11.54％、5.77％和0.00％,且妊娠早期甲状腺功能异常以TPOAb阳性、临床亚甲减和低T4血症为主,妊娠中期以TPOAb阳性、临床亚甲减为主;妊娠早期,TPOAb阳性、TRAb阳性孕妇TSH异常率均高于对应的阴性孕妇(P<0.05);妊娠中期TSH异常率比较差异无统计学意义(P>0.05);甲状腺功能异常孕妇的妊娠高血压、妊娠期糖尿病、妊娠期贫血、剖宫产、产后出血、胎盘早剥、胎膜早破、流产的概率及其娩出新生儿出现早产、新生儿窒息、胎儿窘迫、低体重、畸胎的概率均显著高于甲状腺功能正常孕妇(P<0.05).结论 妊娠期妇女甲状腺功能异常对其妊娠结局及新生儿结局均存在不良影响,临床联合检测甲功五项及TPOAb、TRAb水平评价妊娠期妇女甲状腺功能状态对母婴健康具有重要意义.     

原发性甲状腺功能减退症孕妇甲状腺素替代治疗对甲状腺功能及母婴结局的影响

目的探讨原发性甲状腺功能减退症孕妇甲状腺素替代治疗对甲状腺功能及母婴结局的影响。方法选取2017年5月至2018年5月我院妇产科治疗的原发性甲减孕妇120例,随机分为观察组和对照组各60例,选择同期60例健康孕妇纳入健康组。观察组采用甲状腺素替代疗法,对照组采用安慰剂,观察3组孕妇甲状腺功能各项指标及母婴结局。结果治疗后,观察组血清促甲状腺素(TSH)水平低于治疗前和对照组(P<0.05),游离三碘甲状腺原氨酸(FT3)和游离甲状腺素(FT4)水平高于治疗前和对照组(P<0.05),且观察组与健康组比较差异无统计学意义(P>0.05)。对照组妊娠期高血压、妊娠糖尿病、胎膜早破的发生率均高于观察组和健康组(P<0.05)。对照组早产、小于胎龄儿的发生率均高于观察组和健康组(P<0.05)。结论采用甲状腺素替代疗法治疗孕妇甲减,可有效调节甲状腺素水平,母婴预后良好。     

血清鸢尾素在妊娠期甲状腺功能减退症诊断中的价值

目的:分析血清鸢尾素在妊娠期甲状腺功能减退症(以下简称甲减)诊断中的价值,为妊娠期甲减的诊断筛查工作提供依据.方法:选取120例妊娠期甲减患者作为病例组,选取同期100名接受产检的健康孕妇作为对照组.对两组患者的一般资料、血清促甲状腺激素(thyroid stimulating hormone,TSH)、游离甲状腺素(...     

Hashimoto’s thyroiditis: TGAb,TPOAb, TRAb and recovery from hypothyroidism

Hashimoto described four patients with goiter. The histology of the goiter was characterized by diffuse lymphocytic infiltration, fibrosis and epithelial cell destruction. Thyroglobulin antibody (TGAb) and thyroid peroxidase antibody (TPOAb) have been used to diagnose Hashimoto’s thyroiditis. Patients with positive TGAb and/or TPOAb have been assumed to have Hashimoto’s thyroiditis. Approximately 10% of those with positive TGAb and/or TPOAb have hypothyroidism. There are two types of autoimmune thyroiditis: goitrous Hashimoto’s thyroiditis and atrophic thyroiditis. The latter patients have blocking antibody (thyroid-stimulating hormone [TSH]-stimulation blocking antibody [TSBAb]). TSBAb is a TSH-receptor antibody (TRAb). TSBAb causes thyroid atrophy and hypothyroidism. TGAb and/or TPOAb do not necessarily cause hypothyroidism. Hypothyroid patients with Hashimoto’s thyroiditis usually receive life-long l-thyroxine therapy. However, spontaneous recovery from hypothyroidism has been reported. Patients who had Hashimoto’s hypothyroidism and then Graves’ hyperthyroidism (and vice versa), have also been reported. Hashimoto’s hypothyroidism and Graves’ hyperthyroidism could be the opposite spectrums of one disease.     

TMA与TGA检测对甲状腺疾病的临床诊断价值

根据174例疑诊患者的TMA、TGA，T3，T4放射免疫测定结果及其临床表现进行诊断，结果表明桥本氏甲状腺炎和甲亢所占的比例(分别为38．51％及31．61％）显著高于甲减和亚急性甲状腺炎(分别为6．32％和4．02％)，P＜0．05。甲减患者TGA TMA的阳性率（81．82％)显著高于甲亢(50．91％)，桥本氏甲状腺炎(50．75％)及亚急性甲状腺炎(57．14％)，P＜0．05。单项抗体阳性者以TMA较TGA为多。本文结果提示在甲状腺疾病中TMA，TGA的阳性结果存在相互重叠现象，与T3、T4联检并结合临床表现进行综合分析有助于甲状腺疾病的鉴别诊断并正确指导治疗。     

Disorders of the thyroid gland in neonates and youth: latent hypothyroidism and hyperthyroidism

Etiology and clinical manifestation of subclinical hypothyroidism is different in neonates and in young. In the neonatal period babies present with jaundice and/or constipation due to thyroid hypoplasia, thyroid ectopia or transient hypothyroidism. The main reason for subclinical hypothyroidism in the youth is Hashimoto thyroiditis. Indication for thyroxin therapy in subclinical hypothyroidism is discussed controversial in the literature. For best growing and maturation in childhood thyroxin therapy should be given. Subclinical hyperthyroidism is rare in childhood. The main reasons are Graves' disease or Hashimoto thyroiditis (initial period). The therapy of subclinical hyperthyroidism is the same as in overt hyperthyroidism.     

Thyroid physiology and autoimmunity in pregnancy and after delivery

During pregnancy and after delivery, the maternal thyroid gland faces several metabolic, hemodynamic and immunologic changes. In this article we first summarize the current knowledge on the physiologic adaptation of the healthy thyroid to pregnancy, including variations of thyroid-stimulating hormone and free thyroid hormones, as well as variations of thyroid volume. Our second aim is to illustrate the background of thyroid autoimmunity in this period, which characteristically ameliorates during pregnancy and aggravates after delivery. Although rare during pregnancy, Graves’ disease is the most frequent cause of hyperthyroidism, while Hashimoto’s thyroiditis is the most frequent cause for hypothyroidism. Both types of thyroid dysfunction may lead to detrimental complications in mother and child and therefore timely recognition and treatment is essential. Postpartum autoimmunity most frequently exacerbates in the form of postpartum thyroiditis, which presents with diverse clinical presentations and may lead to permanent hypothyroidism.     

Thyroid blocking antibodies in thyroiditis

Serum from a woman with a history of Hashimoto's thyroiditis, who had given birth to two children with congenital hypothyroidism, contained potent TSH blocking activity. Immunoglobulin preparation from this serum abolished completely TSH-stimulated cAMP production in human thyroid membranes. The blocking activity was associated with the IgG fraction absorbed to and eluted from a Protein A column. The stimulation of adenylate cyclase by a preparation of thyroid-stimulating antibodies from a patient with Graves' disease was also inhibited by the antibodies. In contrast, no effect was observed upon fluoride-stimulated cAMP production. The data indicate that the antibody activity was directed against the TSH receptor. Immunoglobulin preparations from 22 other patients with Hashimoto's thyroiditis and 16 patients with subacute thyroiditis were examined for the existence of TSH receptor blocking antibodies. A blocking activity was found in two of the 22 Hashimoto patients. No such activity was found in the patients with subacute thyroiditis. It appears that thyroid blocking antibodies sometimes contribute to hypothyroidism associated with Hashimoto's thyroiditis.     

Increased serum soluble Fas ligand in hyperthyroid Graves' disease

The interaction of Fas with its ligand (FasL) regulates a number of physiological and pathophysiological process of cell death or apoptosis. Recent studies suggest that Fas and Fas ligand (FasL) interactions among thyrocytes from patients with Hashimoto disease which is caused by thyroid autoimmunity may contribute to clinical hypothyroidism. The role of Fas-FasL interaction in the pathophysiology of Graves' disease has not well been determined. The serum levels of soluble Fas (sFas) and FasL (sFasL) were measured in 48 Japanese patients with Graves' disease (U; untreated hyperthyroidism, T; hyperthyroidism under treatment, E; euthyroidism under treatment and R; remission), destructive thyroiditis (D), subacute thyroiditis (S) and 40 normal controls using commercially available ELISA kits. The levels of sFas (mean +/- SD, ng/ml) were 0.93 +/- 0.30 in normal controls (n = 32), 2.41 +/- 1.28 in U (n = 19), 2.44 +/- 0.79 in T (n = 16), 2.37 +/- 0.55 in E (n = 12), and 2.30 +/- 0.11 in R (n = 6), 2.42 +/- 0.37 in D (n = 3) and 2.68 +/- 0.17 in S (n = 3). There were no significant differences of sFas levels among any groups. While, the mean levels of sFasL (ng/ml) of normal controls were 0.058 +/- 0.02 (n = 40), and those of patients with hyperthyroid Graves' disease (U; 0.34 +/- 0.09 and T; 0.26 +/- 0.05), were significantly higher than those in normal controls (p < 0.005) and with subacute thyroiditis (0.097 +/- 0.001, vs U; p < 0.01, vs T; p < 0.05) but not different from those in E, R and D (E; 0.34 +/- 0.09, R; 0.25 +/- 0.07 and D; 0.31 +/- 0.11, respectively). There was a significant correlation between serum thyrotropin receptor antibody (TRAb) and free thyroxine levels (p < 0.01) while there were no correlation between sFas and sFasL levels and TRAb or free thyroxine levels. The results indicate that the Fas-FasL system contributes to the pathophysiology of hyperthyroid Graves' disease although serum sFas and sFasL levels do not appear to be useful indicators in evaluating disease activity.     

甲状腺过氧化物酶表达在桥本氏甲状腺炎诊断价值的Meta分析

目的 评估甲状腺过氧化物酶表达在桥本氏甲状腺炎诊断的价值.方法 通过对中国期刊全文数据库、中国科技期刊全文数据库、万方数据库进行系统检索,检索起止时间为建库之日至2013年10月载有的所有已正式发表的科研文献.检索条件为在期刊数据库的主题中检索包括“甲状腺过氧化物酶”或“TPOAb”、“桥本氏甲状腺炎”或“桥本氏病”.采用随机效应模型进行数据合并.结果 桥本氏甲状腺炎组与健康对照组血清甲状腺过氧化物酶水平和阳性率差异有统计学意义,桥本氏甲状腺炎组血清甲状腺过氧化物酶水平和阳性率显著高于健康对照组.甲状腺过氧化物酶用于诊断桥本氏甲状腺炎的汇总敏感度为0.89（95％ CI：0.87 ～0.91）,汇总特异度为0.96（95％ CI：0.95 ～0.97）,SROC AUC为0.9843.结论 甲状腺过氧化物酶用于诊断桥本氏甲状腺炎的敏感度和特异度都较高,具有较高的诊断应用价值.     

Therapeutic effect of mesenchymal stem cell on Hashimoto’s thyroiditis in a rat model by modulating Th17/Treg cell balance

Abstract

The autoimmune condition Hashimoto’s thyroiditis (HT) is a disease wherein lymphocytes mediate the autoimmune damage and destruction of the thyroid gland. There are currently no effective means of treating HT, with the primary strategies of thyroid hormone therapy, surgery, or immunomodulatory therapy being associated with serious risks and side effects. There is thus a clear and urgent need to identify novel treatments for HT. In this study, we utilize female SD rats induced HT to evaluated the ability of transplanted MSCs to regulate Th17/Treg interactions in a rat Hashimoto’s thyroiditis (HT) model system. The results showed that Rats in the HT model group exhibited increased thyroid autoantibody levels consistent with successful model development, whereas these levels were lower in rats treated with MSCs. There were also fewer thyroid lesions and less lymphoid infiltration of the thyroid in MSC-treated rats relative to HT model rats, as well as fewer Th17 cells and more Treg cells – an observation consistent with the cytokine analyses. All of these showed that MSCs can regulate Th17/Treg interactions in a rat Hashimoto’s thyroiditis (HT) model system. It suggested that transplanted MSCs could be a potential immunotherapy strategy for the treatment of Hashimoto’s thyroiditis.     

36例甲亢术后一年以上者病因诊断及疗效的再评价

本研究借助放射免疫分析技术（ＲＩＡ）对３６例术前诊断为甲亢并实施手术一年以上的患者，进行了甲状腺激素及其免疫抗体水平的随访检测，以重新评价其术前病因诊断与疗效的确切性。结果表明，凡术后并发甲减的患者，其术前均未做甲状腺自身免疫抗体ＴＭＡ、ＴＧＡ的检测，或可能将原本是桥本氏甲状腺炎或Ｇｒａｖｅｓ病工桥本甲状腺炎患者冒然进行手术，终而造成不可逆的甲减。作者认为，只有采用现代医学技术，提高术前诊断水平，     

T, B and K cells in autoimmune thyroid disease.

The K-cell cytotoxic activity of peripheral blood lymphoid cells from 104 patients with autoimmune thyroid disease and from age and sex matched control subjects was measured using chicken erythrocytes as target cells. Patients with Hashimoto thyroiditis,primary hypothyroidism and thyrotoxicosis who were either newly diagnosed and untreated or had received therapy for less than or equal to 1 year showed a significant increase in K-cell cytotoxic activity. Patients who had received treatment for greater than 1 year and less than or equal to 5 years showed no such comparable increase in cytotoxic activity. Within the group of patients with untreated thyrotoxicosis it was found that K-cell cytotoxic activity was related to both goitre size and serum antibody titre. Thus patients with little or no goitre showed a highly significant elevation of cytotoxic activity whereas patients with moderate to large goitres gave values within the normal range. Similarly patients with no detectable serum thyroid autoantibodies showed high K-cell activity while patients with positive antibody titres did not. It was also shown that neither the absolute number nor the proportion of circulating T and B lymphocytes in patients with autoimmune thyroid disease as assessed by the sheep red cell rosette method and by indirect immunofluorescence was significantly different from that observed in the normal control population. No correlation was found between peripheral blood K-cell cytotoxic activity and the percentage of circulating null cells, i.e. 100-(percentage T + percentage B) in either patients or control subjects.