Diagnosi della SIBO Francesco Azzolini Gastroenterologia ed Endoscopia
Diagnosi della SIBO Francesco Azzolini Gastroenterologia ed Endoscopia digestiva ASMN RE
Diagnosi della SIBO • Traditionally, the direct aspiration and culture of jejunal fluid, with results expressed as CFU/m. L of jejunal fluid, although invasive, has been regarded by many investigators as the gold standard for the diagnosis SIBO Quigley The enteric flora in intestinal failure. Blackwell Publishing; 2008. p. 167– 83.
Diagnosi della SIBO • Although widely quoted and applied, the basis for the classic criteria for the definition of SIBO based on aspirate and culture (105 CFU/m. L of bacteria in the proximal small bowel) is uncertain. Khoshini R, Dai SC, Lezcano S, et al. Dig Dis Sci 2008; 53: 1443– 54.
Diagnosi della SIBO • There were 50 papers that used culture to define SIBO. • In most studies, culture was just assumed to be the historic gold standard to be weighed against another test. • Only three studies tried to validate culture against controls. • Much heterogeneity was seen in sampling. Small bowel fluid aspirates were obtained via endoscopy in 18 papers, by direct sampling through nasal or oral cavity insertion of a tube in 30 others, and by unknown technique(s) in two studies. • The location and amount of small bowel fluid recovered were highly variable or not mentioned. Khoshini R, Dai SC, Lezcano S, et al. Dig Dis Sci 2008; 53: 1443– 54.
• Diversity in defining SIBO, with 22 studies using [105 cfu/ml(colony forming unit/milliliters) as positive results. Three investigators used [104 cfu/ml, seven used [106 cfu/ml, one used [107 cfu/ml, and 14 used variable definitions. • Studies conducted in patient with “stagnant loops”, an extreme form of SIBO, not IBS patients • Poor reproducibility of culture of jejunal contents was found to be less than 38%, compared with 92% for a breath test. 57 Quigley The enteric flora in intestinal failure. Blackwell Publishing; 2008. p. 167– 83.
Diagnosi della SIBO nel 2011
BREATH TEST AL LATTULOSIO
OVERGROWTH BATTERICO lattulos io
BREATH TEST AL LATTULOSIO Author Rhodes JM (Sc J Gastro 1979) King CE (Gastro 1986) Corazza GR (Gastro 1990) Donald I (J Am Ger Soc 1992) Riordan SM (Am J Gastr 1996) g/m. L +ve/Sens Spec ve 10/20 9/55 89% 100% 10/20 18/10 61% 90% 12/24 19/16 68% 44% 10/20 26/26 19% 77% 10/20 18/10 17% 70%
BREATH TEST AL GLUCOSIO
BREATH TEST AL LATTULOSIO • Pochi pazienti • Criterio di positività a 180’ • Non viene dettagliato cosa succede al gruppo positivi (solo 14!!!) a 90’, i veri positivi. • Corretta identificazione scintigrafica del cieco? ? ? Yu, Gut 2011; 60: 334 -340
BREATH TEST AL GLUCOSIO Cause dei risultati falsi negativi Ø assenza di batteri che producono H 2 Ø Incremento non diagnostico nella produzione di H 2 Ø rapido assorbimento del glucosio nella parte prossimale dell’intestino tenue Ø effetto pulizia di una concomitante diarrea Cause di risultati falsi positivi ØContaminazione batterica orale
BREATH TEST AL GLUCOSIO Author King CE (Gastro 1986) Kerlin P (Gastro 1988) Corazza GR (Gastro 1990) Stotzer P (Digestion 2000) Total g/m. L +ve/-ve Sens Spec 80/300 18/10 83% 90% 50/250 27/18 93% 78% 75/375 8/12 62% 83% 50/250 24/22 58% 82% 0. 20 -0. 26 77/62 77% 82%
BREATH TEST AL GLUCOSIO
Diagnosi della SIBO • No adequately validated diagnostic test for SIBO despites decades of recognizing it as a clinical entity. • The most provocative finding was the lack of evidence to verify culture as the representative gold standard test for SIBO.
Diagnosi della SIBO • Breath testing was the most common indirect method for evaluating SIBO. • However, with culture being a poor gold standard, breath testing could not be adequately evaluated.
Perché fare diagnosi di SIBO? • Condizione molto frequente • Test non invasivi • Terapia con scarsi effetti collaterali • Benefici della trattamento per molti pazienti
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