Ulcerative colitis (UC) is one form of presentation of inflammatory bowel disease (IBD), characterised by an immunity disorder that causes abnormal, chronic inflammation in the colon. UC should not be considered a disease limited to the surface of the mucosa, as the perpetuation of colonic inflammation in these patients can lead to functional and structural alteration of the intestine, causing the development of faecal incontinence, stricturing and even degeneration of the mucosa with a higher risk of colorectal carcinoma.1 The drug-based arsenal used in UC, which has increased in recent years, should prevent the progression of the disease by adequately controlling intestinal inflammation. To assess the efficacy of these treatments, therapeutic targets have been established (included in the STRIDE II consensus) that include short-term clinical response and remission with return to normal of inflammatory mediators (faecal calprotectin and C-reactive protein) in the medium term and endoscopic mucosal healing in the long term.2 The aim with these targets is to achieve a better clinical course, avoiding complications such as the development of flare-ups, hospital admission and/or surgery due to UC.
What is disease clearance?In 2020, the concept of disease clearance in UC was proposed. This posits achieving combined clinical, endoscopic and histological remission, seeking a better prognosis of the disease by modifying its natural history and preserving intestinal function.3 The English term was previously coined in dermatology for patients with psoriasis, in whom it was associated with a significant increase in quality of life when a complete “elimination” of skin lesions was achieved.4 It has been established that disease clearance in UC should include clinical remission, which is defined as a partial Mayo score of 0 points (absence of symptoms attributed to UC with normal bowel movement rate and absence of blood in the stool), endoscopic remission, with an endoscopic Mayo score of 0 points (return to normal of the mucosa on endoscopic imaging) and histological remission, achieved with a Nancy index score of 0 points or a Geboes score of ≤2.0 points (absence of neutrophil infiltrate in the mucosa, without erosions or ulcers). All of these conditions have to occur simultaneously to establish the condition of disease clearance.5,6
What are the prognostic implications of disease clearance?Although we have limited clinical data with this novel concept, a 2022 retrospective study evaluated a cohort of 496 patients with ulcerative colitis, who started biological therapy and had a colonoscopy at 16 weeks to assess therapeutic response. Disease clearance was achieved in 109 patients (22.1%) and it was confirmed that, after an average follow-up of 12 months, those with this status had lower rates of hospital admission (5.5% versus 23.1%; p < 0.001) and surgery (1.8% versus 10.9%; p = 0.003) compared to patients who did not achieve disease clearance, demonstrating the medium-to-long-term benefit for this combined target. We assumed that this therapeutic target was ambitious, but the VERDICT trial, which aimed to determine the optimal treatment goal in UC, showed that 41% of patients achieved disease clearance without the use of corticosteroids at 16 weeks of follow-up.5 Prospective studies using disease clearance as a primary endpoint are necessary to adequately assess the importance of the prognostic clinical implications associated with achieving this goal and to determine the benefit it provides in the disease course of these patients compared to each of its components, including histological remission.
How do we translate it into Spanish?There is no commonly accepted translation of this recently described English term. We do not think it is correct to use the direct translation of “lavado de enfermedad” [disease purging], much less to speak of “curación de la enfermedad” [cure of the disease] or “eliminación de la enfermedad” [elimination of the disease]. We propose using the compound term “remisión clínico-endoscópico-histológica” [clinical-endoscopic-histological remission], which accurately reflects the true meaning of disease clearance in English.
