A 34-year-old woman with no relevant history presented in June 2016 a three-week history of liquid stools (frequency eight times/day and three/night) with fresh blood and clots.
Subsequently, colic pain in the left hemiabdomen and fever up to 37.8°C were added for which reason she was hospitalized.
Laboratory tests were performed, highlighting Hcto/Hb 27%/9.3 g/dl; leukocytes 12.300, C-reactive protein (CRP) 117 mg/L (normal < 10), potassium 2.83 Clostridium difficile fecal calugCFdl and albumin
Abdominal-pelvis computed tomography showed diffuse thickening of the colon and rectum.
The colon without ileitis confirms diffuse compromise from the proximal transverse colon to the rectum with presence of deep ulcers (Ullcer Colscopic Severity Index [UCEIS Endoscopic Severity Index]14.
Biopsies show chronic inflammatory (architecture alteration) and acute inflammatory involvement (criptic abscess and cryptic abscess) with a Geboes histological index of 5.315.
Cytomegalovirus study by immunostaining and polymerase chain reaction in negative biopsies.
Treatment was initiated with corticosteroids (hydrolytic acidosis 300 mg/day) and tapering enemas 4 g/night.
The clinical response is unfavourable persisting with bloody liquid stools (six times/ day) and abdominal pain, which is why it is decided on the fifth day to initiate infliximab with AIS (0, 1 and 4 weeks) at a
Four weeks after the start of infliximab, the patient remains in clinical remission (partial Mayo index-0) with FC 426 ug/g.
Prior to the 4th dose (week 12, dose 5 mg/kg) control tests were performed highlighting Hcto/Hb 42% intestinal/13.9 g/dl; leukocytes 6.170, platelets 379.000, inflammatory remission
Biopsies show absence of architectural changes and isolated presence of a small focus of crypt (Geboes index 3.1).
The levels of infliximab and antibodies against infliximab taken prior to the administration of the 4 dose were 1.1 ug/mL and 5.8 UA/mL, respectively.
At week 52 (9th dose of infliximab), the patient remains in clinical remission (Mayo-0) with Hcto/Hb 40%/13.6 g/dl; leukocytes FC 9,240, platelets 332.000,
