Author/Editor		Osredkar, Joško
Title		Dihalni test s sečnino - njegovo mesto v diagnostiki
Translated title		Urea breath test - its role in diagnostics
Type		članek
Source		Zdrav Vestn
Vol. and No.		Letnik 73, št. 1
Publication year		2004
Volume		str. 13-7
Language		slo
Abstract		Background. Each year many patients visit their physicians complaining of digestive symptoms, most commonly functional dyspepsia ("indigestion") or gastroesophageal reflux ("heartburn"). However, many patients with abdominal discomfort are actually suffering from gastric or duodenal ulcers that are commonly caused by H. pylori and thus are curable. Clearing the infection usually heals the ulcer and prevents relapse, so an accurate diagnosis is important. There are several options for diagnosing H. pylori infection: serology to detect antibodies against the bacterium, endoscopic biopsy for urease testing (H. pylori produce a urease that breaks down urea to ammonia and carbon dioxide); histology with special stains; or culture. Unfortunately, these procedures are invasive, expensive and not always accurate. Serological tests require a blood sample and tell oraly that a patient has been exposed to H. pylori at some time in the past, but not whether the patient is currently infected. Endoscopy and biopsy can detect current infection - the CLO test urease test allaws rapid detection of H. pylori in gastric biopsy specimens - but endoscopy and biopsy are unpleasant medical procedures. Recently, noninvasive, sensitive, specific, easy to perform and patient's well accepted method had been developed known as urea breath test (UBT). When an infected person swallows a dose of urea labeled with ara isotope of carbon- carbon-13 (13C) or carbon-14 (14C) - H. pylori in the gastric mucosa break down the labeled urea to form ammonia and labeled carbon dioxide. The carbon dioxide is absorbed into the bloodstream and excreted via the lungs. The patient then exhales into a device that measures the level of carbon dioxide. (Abstract truncated at 2000 characters).
Summary		Izhodišča. Vsako leto mnogo pacientov obišče svoje osebne zdravnike in navaja prebavne motnje, najpogosteje gre za funkcionalno dispepsijo ali gastroezofagealni refluks. Mnogi pacienti imajo dejansko želodčno razjedo ali razjedo v dvanajstniku, ki jo običajno povzroča bakterija Helicobacter pylori (HP) in je ozdravljiva. Ker ozdravitev okužbe običajno pozdravi razjedo in preprečuje ponovni razrast, je bistvenega pomena pravilna diagnoza. Za postavitev diagnoze imamo več možnosti: s serološkimi testi določimo protitelesa proti bakteriji, endoskopska biopsija nam daje material za izvedbo hitrega ureaznega testa, biopt lahko obarvamo s specialnimi barvili, celice lahko kultiviramo. Na žalost so te metode invazivne, drage in vedno ne tudi dovolj natančne. Za serološke teste potrebujemo kri, iz tega rezultata pa lahko izvemo samo to, ali je bil pacient pred časom izpostavljen bakteriji, ne pa, ali je bakterija tudi trenutno prisotna. Endoskopija in biopsija lahko detektirata trenutno okužbo - CLO ureazni test nam omogoča hitro določitev bakterije HP v bioptu - sta pa to metodi, ki sta invazivni, za pacienta neprijetni. Test, ki je široko dostopen in je občutljiv, specifičen in neinvaziven, je dihalni test s sečnino za detekcijo okužbe s HP. Ko okužena oseba pogoltne odmerek sečnine ki, je označena z izotopom ogljika (13C ali 14C), HP v želodčni mukozi cepi sečnino na amoniak in ogjikov dioksid, ki ima v tem primeru tudi izotop (13C ali 14C). Ogljikov dioksid se absorbira v krvni obtok in se nato izloča z izdihanim zrakom prek p juč. Pacient izdihne zrak v epruveto oziroma balon, v izdihanem zraku pa izmerimo delež izotopa. Dihalni test s sečnino je specifičen za HP (samo tiste bakterije, ki proizvajajo ureazo) in občutljiv (označena sečnina se porazdeli po celotni površini želodca in tako odraža celotno ureazno aktivnost) ter daje ponovljive rezultate. (Izvleček prekinjen pri 2000 znakih).
Descriptors		PEPTIC ULCER HELICOBACTER INFECTIONS HELICOBACTER PYLORI UREA BREATH TESTS