Calprotectin
GastrointestinalÚltima revisão: 7 de abril de 2026. Abordagem de fontes: contexto padrão de interpretação laboratorial, material médico de referência e orientações clínicas ou de saúde pública quando relevantes.
O que é Calprotectin?
Calprotectin is a calcium- and zinc-binding protein released primarily by neutrophils (a type of white blood cell) during intestinal inflammation. When the gut lining is inflamed, neutrophils migrate into the intestinal wall and release calprotectin into the bowel lumen, where it can be measured in stool samples. Fecal calprotectin is remarkably stable—it resists degradation by intestinal bacteria and enzymes and can remain stable in stool samples at room temperature for up to 7 days, making it a practical and reliable biomarker.
Fecal calprotectin has become one of the most valuable non-invasive tests in gastroenterology. Its primary clinical utility lies in distinguishing inflammatory bowel disease (IBD)—Crohn's disease and ulcerative colitis—from irritable bowel syndrome (IBS) and other functional gastrointestinal disorders. Calprotectin levels correlate closely with the degree of intestinal inflammation as assessed by endoscopy and histology, making it valuable for both diagnosis and ongoing monitoring of disease activity. The test is particularly useful in reducing unnecessary colonoscopies in patients with gastrointestinal symptoms.
Por que isso importa
Fecal calprotectin is a highly sensitive and specific marker for intestinal inflammation that can distinguish organic bowel disease from functional disorders without invasive procedures. In clinical practice, a normal calprotectin level in a patient with chronic abdominal symptoms effectively rules out IBD with greater than 95% negative predictive value, potentially avoiding unnecessary colonoscopy. For patients with established IBD, serial calprotectin measurements detect subclinical inflammation and predict relapse weeks before symptoms appear, allowing preemptive treatment adjustments. This monitoring approach has been shown to improve outcomes and reduce hospitalizations in IBD patients.
Faixas de referência normais
| Grupo | Faixa | Unidade |
|---|---|---|
| Adults | <50 | mcg/g |
| Borderline | 50–200 | mcg/g |
| Elevated (likely inflammation) | >200 | mcg/g |
| Infants (<1 year) | Higher baseline, up to 500 | mcg/g |
As faixas de referência podem variar entre laboratórios. Sempre compare seus resultados com as faixas fornecidas pelo seu local de exame.
O que significam níveis altos de fCal
Causas comuns
- Inflammatory bowel disease (Crohn's disease, ulcerative colitis)
- Infectious gastroenteritis (bacterial, viral)
- Colorectal cancer
- NSAIDs-induced enteropathy
- Diverticulitis
- Celiac disease (moderately elevated)
- Intestinal polyps
- Microscopic colitis
Possíveis sintomas
- Chronic diarrhea (often bloody in IBD)
- Abdominal pain and cramping
- Urgency and increased frequency of bowel movements
- Fatigue and malaise
- Weight loss
- Fever (in acute flares or infection)
- May be asymptomatic in subclinical inflammation
O que fazer: Elevated fecal calprotectin warrants further investigation. Levels above 200 mcg/g are highly suggestive of organic inflammatory disease and typically prompt colonoscopy with biopsies. For known IBD patients, rising calprotectin signals active inflammation or impending relapse—your gastroenterologist may adjust immunosuppressive therapy accordingly. Rule out infectious causes with stool cultures and C. difficile testing. NSAID use should be discontinued before retesting, as these drugs can independently elevate calprotectin.
O que significam níveis baixos de fCal
Causas comuns
- Normal finding—indicates absence of significant intestinal inflammation
- Irritable bowel syndrome (IBS)—typically normal calprotectin
- Functional gastrointestinal disorders
- IBD in remission
Possíveis sintomas
- No symptoms attributable to low calprotectin—this is the expected healthy result
O que fazer: A low fecal calprotectin level is reassuring and effectively rules out significant inflammatory bowel disease with high confidence. If gastrointestinal symptoms persist despite normal calprotectin, evaluation for functional disorders like IBS, food intolerances, or celiac disease (via serology) is appropriate. For IBD patients, low calprotectin confirms mucosal healing and supports current treatment adequacy.
Quando o exame de fCal é recomendado?
- To differentiate IBD from IBS in patients with chronic GI symptoms
- To monitor disease activity in known IBD patients
- To predict relapse in IBD patients in clinical remission
- To assess response to IBD therapy
- Before considering colonoscopy in patients with non-alarming symptoms
- When infectious gastroenteritis is suspected
Perguntas frequentes
Biomarcadores relacionados
Leitura relacionada
Referências e abordagem de revisão
As páginas do glossário de biomarcadores são explicações educativas e devem ser interpretadas junto com as faixas de referência e observações fornecidas pelo seu laboratório e pelo seu médico. Para conhecer nossos padrões editoriais e processo de revisão, veja nossa Política editorial e a nossa revisão de conteúdo.
Quer analisar seus níveis de fCal?
Envie seus resultados de exames para receber uma análise instantânea com IA de todos os seus biomarcadores.
Enviar resultados de exames →Aviso médico: Estas informações são apenas educativas e não substituem orientação, diagnóstico ou tratamento médico profissional. As faixas de referência podem variar entre laboratórios. Sempre converse com seu profissional de saúde sobre a interpretação dos seus resultados específicos.