{"id":243,"date":"2025-06-11T13:40:53","date_gmt":"2025-06-11T13:40:53","guid":{"rendered":"https:\/\/analizesanocare.ro\/?post_type=product&#038;p=243"},"modified":"2025-08-08T13:57:08","modified_gmt":"2025-08-08T13:57:08","slug":"factor-de-necroza-tumorala-tnf-alfa","status":"publish","type":"product","link":"https:\/\/analizesanocare.ro\/en\/analiz\u0103\/factor-de-necroza-tumorala-tnf-alfa\/","title":{"rendered":"Factor de necroz\u0103 tumoral\u0103 TNF-alfa"},"content":{"rendered":"<div class=\"info-content content-informatii-generale\">\n<h2><strong>Informa\u0163<\/strong><strong>ii generale \u015fi recomand\u0103ri pentru determinarea TNF<\/strong><strong>-\u03b1<\/strong><\/h2>\n<p>TNF (tumor necrosis factor) este o citokin\u0103 proinflamatorie al c\u0103rui nume deriv\u0103 din capacitatea de a distruge celulele tumorale \u015fi de a induce necroza hemoragic\u0103\u00a0\u00een\u00a0tumorile transplantate la \u015foarece<sup>5<\/sup>.<\/p>\n<p>TNF-\u03b1 (casectina) \u015fi TNF-\u03b2 (limfotoxina) au fost descrise ini\u0163ial ca factori citotoxici produ\u015fi de macrofage \u015fi respectiv de limfocite; ulterior s-a descoperit c\u0103 TNF-\u03b1 \u015fi TNF-\u03b2 sunt dou\u0103 proteine care prezint\u0103 omologie la 34% din secven\u0163ele de aminoacizi<sup>3;5<\/sup>. Ambii mediatori ac\u0163ioneaz\u0103 asupra celulelor \u0163int\u0103 prin aceea\u015fi receptori \u015fi din acest motiv au efecte biologice similare, dar nu identice.<\/p>\n<p>Gena pentru TNF-\u03b1 este localizat\u0103 pe cromozomul 6. In condi\u0163ii de denaturare TNF-\u03b1 este o protein\u0103 de 17 kDa, neglicozilat\u0103. Forma biologic activ\u0103 a\u00a0TNF-\u03b1 este cea de trimer. Pe l\u00e2ng\u0103 aceast\u0103 form\u0103 solubil\u0103 exist\u0103 \u015fi o form\u0103 legat\u0103 de membran\u0103 (28 kDa), situat\u0103 pe suprafa\u0163a celulelor produc\u0103toare de TNF-\u03b1 \u015fi care serve\u015fte drept pool pentru forma solubil\u0103, generat\u0103 prin clivare proteolitic\u0103<sup>3<\/sup>.<\/p>\n<p>TNF-\u03b1 este produs nu numai de macrofage \u015fi monocite, ci \u015fi de limfocite, mastocite, neutrofile, keratinocite, astrocite, microglii, celule musculare netede \u015fi unele linii celulare tumorale<sup>5<\/sup>. Cantit\u0103\u0163i mari de TNF sunt eliberate la contactul macrofagelor, limfocitelor T CD4+ \u015fi a celulelor natural-killer (NK) cu lipopolizaharidele, produ\u015fii bacterieni \u015fi interleukina 1<sup>3<\/sup>.<\/p>\n<p>TNF-\u03b1 ac\u0163ioneaz\u0103 direct prin doi receptori de suprafa\u0163\u0103 distinc\u0163i, denumi\u0163i TNFR I \u015fi TNFR II, av\u00e2nd greut\u0103\u0163i moleculare diferite<sup>3;4;5<\/sup>. Ace\u015fti receptori pot fi identifica\u0163i pe toate tipurile de celule, cu excep\u0163ia eritrocitelor. Por\u0163iuni ale acestor receptori sunt clivate de c\u0103tre proteaze \u015fi ajung \u00een mediul extracelular form\u00e2nd receptori solubili; ace\u015ftia ac\u0163ioneaz\u0103 ca inhibitori endogeni de TNF-\u03b1 \u015fi regleaz\u0103 astfel nivelul de TNF-\u03b1 extracelular<sup>4<\/sup>.<\/p>\n<p>Legarea TNF-\u03b1 de receptor determin\u0103 modific\u0103ri conforma\u0163ionale \u00een structura receptorului, care conduc la activarea \u00een cascad\u0103 a transcrip\u0163iei altor proteine implicate \u00een proliferarea celular\u0103, r\u0103spunsul inflamator \u015fi apoptoza celular\u0103. TNF-\u03b1 poate avea o ac\u0163iune local\u0103 paracrin\u0103 (cre\u015fterea local\u0103 a concentra\u0163iei TNF poate cauza semnele cardinale ale inflama\u0163iei: ro\u015feat\u0103, durere, c\u0103ldur\u0103 \u015fi tumefac\u0163ie) sau poate ac\u0163iona la distan\u0163\u0103, asemenea hormonilor endocrini<sup>5<\/sup>. Datorit\u0103 prezen\u0163ei receptorilor s\u0103i \u00een majoritatea \u0163esuturilor, TNF-\u03b1 exercit\u0103 o varietate larg\u0103 de efecte biologice:<\/p>\n<ul>\n<li>efecte citolitice \u015fi citostatice asupra celulelor tumorale;<\/li>\n<li>efect chemotactic asupra neutrofilelor<sup>3<\/sup>;<\/li>\n<li>cre\u015fte permeabilitatea la nivelul celulelor endoteliale din regiunea cu inflama\u0163ie; acestea nu determin\u0103 numai acumularea de celule imune ci are impact \u015fi asupra procesului de coagulare;<\/li>\n<li>activeaz\u0103 diverse procese metabolice din celulele musculare si adipocite pentru a furniza energia necesar\u0103 reac\u0163iei inflamatorii<sup>1<\/sup>;<\/li>\n<li>la nivelul macrofagelor stimuleaz\u0103 fagocitoza \u015fi producerea de prostaglandina E2;<\/li>\n<li>la nivelul altor \u0163esuturi cre\u015fte rezisten\u0163a la insulin\u0103;<\/li>\n<li>activeaz\u0103 osteoclastele, deci stimuleaz\u0103 resorb\u0163ia osoas\u0103;<\/li>\n<li>este factor de cre\u015ftere pentru fibrobla\u015fti \u015fi stimuleaz\u0103 sinteza de colagenaz\u0103;<\/li>\n<li>intensific\u0103 proliferarea limfocitelor T dup\u0103 stimularea cu interleukina 2<sup>3<\/sup>;<\/li>\n<li>determin\u0103 anorexie \u015fi febr\u0103, ac\u0163ionand ca un pirogen endogen<sup>1<\/sup>;<\/li>\n<li>este responsabil pentru sindromul de casexie asociat cu procesele maligne \u015fi cu majoritatea infest\u0103rilor parazitare<sup>5<\/sup>.<\/li>\n<\/ul>\n<p>Determinarea nivelului seric de TNF-\u03b1 constituie un marker pentru r\u0103spunsul inflamator sistemic (SIRS) asociat cu sepsisul, traumatismele \u015fi insuficien\u0163a cardiac\u0103. Anumite studii au indicat asocierea concentra\u0163iei de TNF-\u03b1 \u00een lichidul cefalorahidian cu gradul de activitate \u00een scleroza multipl\u0103; pe de alt\u0103 parte, determinarea TNF-\u03b1 ar putea fi util\u0103 \u00een diferen\u0163ierea meningitei bacteriene de alte cauze de meningit\u0103<sup>1<\/sup>.<\/p>\n<p>Studiile efectuate pe animale au ar\u0103tat c\u0103 TNF-\u03b1 este implicat \u00een patogenia poliartritei reumatoide \u015fi a bolilor inflamatorii intestinale, datorit\u0103 efectului proinflamator exercitat prin activarea celulelor endoteliale \u015fi inducerea chemotaxiei neutrofilelor. Din acest motiv, tratamentul acestor afec\u0163iuni include \u015fi inhibitori ai TNF-\u03b1: fie anticorpi monoclonali anti- TNF-\u03b1 (infliximab, adalimubab), fie proteine de fuziune anticorp-receptor, respectiv TNFRII-IgG1 (etanercept)<sup>5<\/sup>.<\/p>\n<p>Nivelul TNF-\u03b1 poate fi utilizat \u00een diagnosticarea unor afec\u0163iuni imune \u015fi \u00een monitorizarea tratamentelor, doar \u00een corela\u0163ie cu date clinice \u015fi paraclinice complementare<sup>2<\/sup>.<\/p>\n<h2><strong>Preg\u0103tire pacient <\/strong><\/h2>\n<p>\u00e0 jeun (pe nem\u00e2ncate) sau postprandial<sup>2<\/sup>.<\/p>\n<p><strong>Specimen recoltat <\/strong>\u2013 s\u00e2nge venos<sup>2<\/sup>.<\/p>\n<p><strong>Recipient de recoltare <\/strong>\u2013 vacutainer fara anticoagulant, cu\/fara gel separator<sup>2<\/sup>.<\/p>\n<p><strong>Cantitate recoltat\u0103 <\/strong>\u2013 minim 0.5 mL ser<sup>2<\/sup>.<\/p>\n<p><strong>Cauze de respingere a probei<\/strong> \u2013 specimen intens hemolizat, icteric, lipemic sau contaminat bacterian; probe care nu au sosit la laborator congelate<sup>2<\/sup>.<\/p>\n<p><strong>Prelucrare necesar\u0103 dup\u0103 recoltare <\/strong>\u2013 se separ\u0103 serul prin centrifugare c\u00e2t mai repede dup\u0103 formarea complet\u0103 a coagulului, iar proba va fi imediat congelat\u0103 la -20\u00b0C; probele recoltate \u00een afara punctelor laboratorului vor fi transportate \u00een recipientul destinat probelor congelate<sup>2<\/sup>.<\/p>\n<p><strong>Stabilitate prob\u0103 <\/strong>\u2013 serul este stabil 1 lun\u0103 la -20\u00b0C; nu decongela\u0163i\/recongela\u0163i<sup>2<\/sup>.<\/p>\n<p><strong>Metod\u0103<\/strong> \u2013 metoda imunochimic\u0103 cu detec\u0163ie prin chemiluminiscen\u0163\u0103 (CLIA)<sup>2<\/sup>.<\/p>\n<h2><strong>Valori de referin\u0163\u0103 Factor de necroz\u0103 tumoral\u0103 TNF-alfa<\/strong><\/h2>\n<p>&lt; 8.1pg\/ml<sup>2<\/sup>.<\/p>\n<h2><strong>Interpretarea rezultatelor<\/strong><\/h2>\n<p>Niveluri crescute de TNF-\u03b1 se \u00eenregistreaz\u0103 \u00een sepsis, traumatisme, <a href=\"https:\/\/www.synevo.ro\/boli-autoimune-cauze-si-diagnostic\/\" data-wpel-link=\"internal\">boli autoimune<\/a> \u015fi inflamatorii cronice (artrita reumatoid\u0103, spondilita ankilopoetica, <a href=\"https:\/\/www.synevo.ro\/boala-crohn-si-investigatiile-de-laborator\/\" data-wpel-link=\"internal\">boala Crohn<\/a>, <a href=\"https:\/\/www.synevo.ro\/psoriazis-boala-invalidanta-social\/\" data-wpel-link=\"internal\">psoriazis<\/a>), boli infec\u0163ioase \u015fi rejetul de gref\u0103<sup>2<\/sup>.<\/p>\n<p>&nbsp;<\/p>\n<p><strong>Bibliografie<\/strong><\/p>\n<div>\u00a01. Hans D. Volk, Gernot Keyser, Gerd R. Burmester. Cytokines and Cytokine Receptors. In Clinical Laboratory Diagnostics-Use and Assessment of Clinical Laboratory Results. Lothar Thomas. TH-Books Verlagsgesellschaft mbH, Frankfurt \/Main, Germany,1 ed. 1998, 764-772.<\/div>\n<div>2. Laborator Synevo. Referin\u0163ele specifice tehnologiei de lucru utilizate 2010. Ref Type: Catalog<\/div>\n<div>3. Laboratory Corporation of America. Directory of Services and Interpretive Guide. Tumor Necrosis Factor-\u03b1. <a href=\"https:\/\/www.labcorp.com\" target=\"_blank\" rel=\"noopener nofollow external noreferrer\" data-wpel-link=\"external\">www.labcorp.com<\/a> 2010. Ref Type: Internet Communication.<\/div>\n<div>4. Magda Negru. Inflama\u0163ia. \u00cen Esen\u0163ialul \u00een Reumatologie. Editura Amaltea, 2007, 56.<\/div>\n<div>5. Richard A. McPetersen, Matthew R. Pincus. Immunology and immunopathology. In Henry\u2019s Clinical Diagnosis and Management by Laboratory Methods- Sauders Elsevier 21st-Ed 2007, 867.<\/div>\n<\/div>","protected":false},"excerpt":{"rendered":"<p>Informa\u0163ii generale \u015fi recomand\u0103ri pentru determinarea TNF-\u03b1 TNF (tumor necrosis factor) este o citokin\u0103 proinflamatorie al c\u0103rui nume deriv\u0103 din capacitatea de a distruge celulele tumorale \u015fi de a induce necroza hemoragic\u0103\u00a0\u00een\u00a0tumorile transplantate la \u015foarece5. TNF-\u03b1 (casectina) \u015fi TNF-\u03b2 (limfotoxina) au fost descrise ini\u0163ial ca factori citotoxici produ\u015fi de macrofage \u015fi respectiv de limfocite; ulterior [&hellip;]<\/p>\n","protected":false},"featured_media":0,"template":"","meta":{"_acf_changed":false},"product_brand":[],"product_cat":[89,44],"product_tag":[],"class_list":["post-243","product","type-product","status-publish","product_cat-citokine","product_cat-teste-specializate-de-alergologie-si-imunologie","first","instock","shipping-taxable","purchasable","product-type-simple"],"acf":[],"_links":{"self":[{"href":"https:\/\/analizesanocare.ro\/en\/wp-json\/wp\/v2\/product\/243","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/analizesanocare.ro\/en\/wp-json\/wp\/v2\/product"}],"about":[{"href":"https:\/\/analizesanocare.ro\/en\/wp-json\/wp\/v2\/types\/product"}],"wp:attachment":[{"href":"https:\/\/analizesanocare.ro\/en\/wp-json\/wp\/v2\/media?parent=243"}],"wp:term":[{"taxonomy":"product_brand","embeddable":true,"href":"https:\/\/analizesanocare.ro\/en\/wp-json\/wp\/v2\/product_brand?post=243"},{"taxonomy":"product_cat","embeddable":true,"href":"https:\/\/analizesanocare.ro\/en\/wp-json\/wp\/v2\/product_cat?post=243"},{"taxonomy":"product_tag","embeddable":true,"href":"https:\/\/analizesanocare.ro\/en\/wp-json\/wp\/v2\/product_tag?post=243"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}