Se recolteaza a jeun (pe nemancate).
Se foloseste metoda spectrofotometrica (kinetica).
! Valorile normale ale ALT nu exclud intotdeauna o afectiune hepatica.
Valorile de referinta sunt dependente de varsta si de sex!
ALT este mai putin sensibil decat AST in boala hepatica indusa de alcool.
Conditii fiziologice - in sarcina pot aparea valori scazute.
Conditii patologice - cresteri ale ALT pot fi intalnite la pacientii cu traumatisme musculare, rabdomioliza, polimiozita si dermatomiozita, dar in aceste cazuri apar si niveluri crescute de creatinkinaza care orienteaza spre o afectiune musculara. Injectiile intramusculare pot provoca o crestere usoara a ALT. Niveluri crescute de ALT mai pot aparea la pacientii obezi.
Interferente cu medicamente:
Cresteri :
- Medicamente care produc colestaza : acid aminosalicilic, amitriptilina, steroizi anabolizanti, androgeni, azatioprina, benzodiazepine, carbamazepin, carbazona, clorotiazida, clorpropamida, acid clavulanic, dapsone.
- Medicamente care produc o afectare hepatocelulara: acetaminofen, alopurinol, acid aminosalicilic, amiodarona, amitriptilina, steroizi anabolizanti, androgeni, asparaginaza, aspirina, azatioprina, carbamazepin, chenodiol, clorambucil, cloramfenicol, clorpropamida, cimetidina, ciclosporine, danazol, dantrolen, dapsone, diclofenac, dicumarol (rar), disulfiram, eritromicina, estrogeni, etionamida, glyburide (glibenclamid), saruri de aur, imipramina, mercaptopurina, metimazol, acid nicotinic, nitrofurantoin, contraceptive orale, estrogeni, etanol (exces), etionamida, fluconazol, halotan, ibuprofen, imipramina, indometacin, saruri de fier (supradozare), izoniazida, ketoconazol, inhibitori MAO, mercaptopurina, metotrexat, metoxifluran, metildopa, naproxen, papaverina, parametadion, penicilamina, peniciline, fenotiazine, fenilbutazona, progestative, propoxifen, sulfonamide, sulfone, sulindac, tamoxifen, tolbutamida, perhexilin, fenazopiridina, fenidiona, fenobarbital, fenilbutazona, fenitoin, plicamicin (mitramicin), probenecid, procainamida, propiltiouracil, pirazinamida, chinidina, rifampin, salicilati, sulfasalazina, sulfonamide, tamoxifen, tetracicline, trimetadiona, acid valproic, vitamina A, warfarina (rar).
- Multe alte medicamente pot determina cresteri care in general sunt tranzitorii dar in anumite cazuri indica o hepatotoxicitate. Intre acestea sunt incluse : acebutolol, aminoglicozide, azitromicin, bromocriptin, captopril, cefalosporine, claritromicin, clindamicin, clofibrat, clotrimazol, ciclosporine, citarabina, dacarbazina, didanozin, disopiramid, enfluran, etambutol, fenofibrat, fluorochinolone (ex: ciprofloxacin), foscarnet, ganciclovir, heparina, interferon, interleukina 2, labetalol, levamisol, levodopa, lincomicin, mebendazol, mefloquin, metoprolol, nifedipin, omeprazol, ondansetron, penicilina, pentamidin, pindolol, piroxicam, propoxyfen, protriptilina, chinina, ranitidina, retinol, ritodrin, sargramostim, streptozocin, sulfoniluree, tiotixen, tioguanina, trimetoprim, verapamil, zalcitabin, zidovudin.
Scaderi:
- aspirina, ciclosporina, fenotiazine, interferon, ketoprofen, simvastatin, ursodiol.
Interferente analitice - contaminarea probei cu eritrocite poate determina valori fals crescute.
Lipemia poate creste absorbanta probei, valoarea ALT neputand fi calculata.