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ulcerative colitis ( uc ) is a chronic inflammatory disorder of the colon characterized by colonic mucosal ulceration . in japan
, we have several therapies which induce remission in severe uc , including corticosteroids , anti - tnf- therapy ( infliximab , adalimumab ) , leukocytapheresis , and tacrolimus .
tacrolimus is an immunosuppressive macrolide isolated from streptomyces tsukubaensis , and it is known for potent inhibition activity of helper t lymphocyte activation .
it has been shown to be an effective treatment for inducing remission in patients with severe uc that is refractory to high - dose corticosteroids [ 2 , 3 ] .
on the other hand , when a patient with uc has the complication of colonic dilatation , we must be concerned about a shift to toxic megacolon .
toxic megacolon is a fatal complication of uc characterized by total or segmental nonobstructive colonic dilatation of at least 6 cm .
. however , treatment for uc with colonic dilatation of less than 6 cm has not yet been established , and the efficacy of tacrolimus as a rescue therapy for uc with colonic dilatation has not been reported .
we report 2 cases of uc with intestinal tract dilatation treated with tacrolimus in which emergency colectomy was avoided .
these 2 cases suggest that tacrolimus is effective for uc with colonic dilatation as a rescue therapy .
a 53-year - old man was transferred from a local hospital for steroid - resistant uc . he was diagnosed with uc ( proctitis type ) at the age of 48 and maintained remission for 5 years .
he was admitted to the local hospital complaining of worsening abdominal pain and bloody diarrhea .
colonoscopy showed that inflammation extended to the whole colon , and he was treated with medication consisting of 5-asa , granulocytapheresis ( twice a week ) , and high - dose prednisolone ( 1.0 mg / kg / day ) , but bloody diarrhea did not improve , and anemia progressed such that blood transfusions were necessary . when he was referred to our hospital
the results of the blood examination were : white blood cells 13,630 l , hemoglobin 9.6 g / dl , serum albumin 2.4 g / dl , and c - reactive protein 5.7 mg / dl .
plain x - ray showed dilatation of the transverse colon reaching diameters of 5.5 cm ( fig .
after we had obtained full informed consent from the patient , oral tacrolimus medication was started at a dose of 0.05 mg / kg / day . according to a previous study
, the dosage of tacrolimus was adjusted to produce a trough blood level of 1015 ng / ml during the first 2 weeks , and thereafter , the trough blood level was maintained at a lower level of between 5 and 10 ng / ml .
the transverse colon dilatation was improved on plain x - ray after 2 weeks of therapy ( fig .
1c ) , and a barium enema examination detected pseudopolyposis in the transverse and descending colon , without active ulcers or stenosis ( fig .
oral tacrolimus was continued for 3 months , and the patient started azathioprine ( 25 mg / day ) 1 month before the cessation of tacrolimus .
a 64-year - old man was transferred from a local hospital for steroid - resistant uc . he was diagnosed with uc ( left - sided colitis type ) at the age of 63 and was treated with 5-asa , which induced remission .
eight months later , he had a relapse of the disease in association with fever , abdominal pain , and bloody diarrhea .
he was admitted to the hospital and treated with leukocytapheresis ( two sessions per week , four sessions in total ) , high - dose prednisolone ( 1.0 mg / kg / day ) , and steroid pulse therapy ( hydrocortisone 1,000 mg / day for 3 days ) , but his symptoms did not improve . when he was referred to our hospital
, he was having bloody diarrhea 10 times a day and abdominal pain , and his temperature was 39.0c .
the results of the blood examination were : white blood cells 110,500 l , hemoglobin 7.0 g / dl , serum albumin 1.0 g / dl , and c - reactive protein 5.1 mg / dl .
plain x - ray revealed dilatation of the transverse colon reaching diameters of 5.0 cm ( fig .
because we were concerned about progression to toxic megacolon , we continued medical treatment in cooperation with the surgeons .
ganciclovir injection was also started at a dose of 1,000 mg / day because his serum was positive for cytomegalovirus antigen .
one week after beginning the therapy , bloody diarrhea had disappeared and the serum c - reactive protein level had decreased .
dilatation of the transverse colon was improved on plain x - ray at 2 weeks after starting therapy ( fig .
colonoscopy performed 32 days later showed diffuse inflammatory mucosa with edema , erosions , and ulcers in the rectum and sigmoid colon .
however , the proximal sigmoid colon became severely constricted , and we were not able to insert the colonoscope deeper into the colon ( fig . 2c ) .
barium enema examination showed extensive stenoses from the proximal sigmoid colon to the ascending colon ( fig .
because we thought that oral intake might be difficult due to these strictures , we decided to perform a subtotal colectomy .
the pathological tissue of the resected colon showed that inflammatory cells had profoundly infiltrated the submucosal layer to the muscle layer , and this lesion had become severely fibrotic .
a 53-year - old man was transferred from a local hospital for steroid - resistant uc . he was diagnosed with uc ( proctitis type ) at the age of 48 and maintained remission for 5 years .
he was admitted to the local hospital complaining of worsening abdominal pain and bloody diarrhea .
colonoscopy showed that inflammation extended to the whole colon , and he was treated with medication consisting of 5-asa , granulocytapheresis ( twice a week ) , and high - dose prednisolone ( 1.0 mg / kg / day ) , but bloody diarrhea did not improve , and anemia progressed such that blood transfusions were necessary . when he was referred to our hospital
the results of the blood examination were : white blood cells 13,630 l , hemoglobin 9.6 g / dl , serum albumin 2.4 g / dl , and c - reactive protein 5.7 mg / dl .
plain x - ray showed dilatation of the transverse colon reaching diameters of 5.5 cm ( fig .
after we had obtained full informed consent from the patient , oral tacrolimus medication was started at a dose of 0.05 mg / kg / day . according to a previous study
, the dosage of tacrolimus was adjusted to produce a trough blood level of 1015 ng / ml during the first 2 weeks , and thereafter , the trough blood level was maintained at a lower level of between 5 and 10 ng / ml .
the transverse colon dilatation was improved on plain x - ray after 2 weeks of therapy ( fig .
1c ) , and a barium enema examination detected pseudopolyposis in the transverse and descending colon , without active ulcers or stenosis ( fig .
oral tacrolimus was continued for 3 months , and the patient started azathioprine ( 25 mg / day ) 1 month before the cessation of tacrolimus .
a 64-year - old man was transferred from a local hospital for steroid - resistant uc . he was diagnosed with uc ( left - sided colitis type ) at the age of 63 and was treated with 5-asa , which induced remission .
eight months later , he had a relapse of the disease in association with fever , abdominal pain , and bloody diarrhea .
he was admitted to the hospital and treated with leukocytapheresis ( two sessions per week , four sessions in total ) , high - dose prednisolone ( 1.0 mg / kg / day ) , and steroid pulse therapy ( hydrocortisone 1,000 mg / day for 3 days ) , but his symptoms did not improve .
when he was referred to our hospital , he was having bloody diarrhea 10 times a day and abdominal pain , and his temperature was 39.0c .
the results of the blood examination were : white blood cells 110,500 l , hemoglobin 7.0 g / dl , serum albumin 1.0 g / dl , and c - reactive protein 5.1 mg / dl .
plain x - ray revealed dilatation of the transverse colon reaching diameters of 5.0 cm ( fig .
because we were concerned about progression to toxic megacolon , we continued medical treatment in cooperation with the surgeons .
ganciclovir injection was also started at a dose of 1,000 mg / day because his serum was positive for cytomegalovirus antigen .
one week after beginning the therapy , bloody diarrhea had disappeared and the serum c - reactive protein level had decreased .
dilatation of the transverse colon was improved on plain x - ray at 2 weeks after starting therapy ( fig .
colonoscopy performed 32 days later showed diffuse inflammatory mucosa with edema , erosions , and ulcers in the rectum and sigmoid colon .
however , the proximal sigmoid colon became severely constricted , and we were not able to insert the colonoscope deeper into the colon ( fig . 2c ) .
barium enema examination showed extensive stenoses from the proximal sigmoid colon to the ascending colon ( fig .
because we thought that oral intake might be difficult due to these strictures , we decided to perform a subtotal colectomy .
the pathological tissue of the resected colon showed that inflammatory cells had profoundly infiltrated the submucosal layer to the muscle layer , and this lesion had become severely fibrotic .
a randomized , controlled study demonstrated the efficacy and safety of oral tacrolimus for inducing remission of refractory uc , and there are many case reports showing tacrolimus to be effective for uc refractory to other treatments [ 5 , 6 ] .
however , there are , to our knowledge , no reports of treatment of uc with intestinal tract dilatation with tacrolimus , and no guidelines for medical treatment of this condition have been published .
complications of toxic megacolon must be considered when the intestinal tract dilatation is greater than 6.0 cm .
we were concerned about the development of high - risk toxic megacolon in these 2 cases , which were successfully treated with tacrolimus and in which emergency surgery was avoided , and consider these cases to be highly informative and valuable .
although case 2 was treated with tacrolimus and emergency colectomy could be avoided , extensive severe intestinal tract stenoses developed as the multiple deep ulcers healed .
a study at mount sinai hospital   found that 70 strictures were identified in 59 ( 5.1%percnt ; ) of 1,156 patients .
seventeen ( 24%percnt ; ) of these 70 strictures were malignant , and the remaining 53 ( 76%percnt ; ) strictures were benign .
first , because of severe inflammation , inflammatory cells infiltrate not only the submucosal layer but also the muscle layer .
second , fibrosis of the submucosal layer and/or muscle layer occurs during the healing process .
lastly , ischemic or necrotic change occurs in the course of uc . there are case reports of patients with uc complicated by ischemic colitis and by aortitis syndrome . in case 2 ,
moderate inflammatory cells had infiltrated the submucosal and muscle layers , and this area had become severely fibrotic .
we thought that there is severe inflammation as the intestinal tract is expanded , and rapid mucosal healing had occurred due to the tacrolimus . in conclusion ,
we believe tacrolimus to be a worthwhile method of treatment , with dosages determined in cooperation with the surgeons , in uc patients with intestinal tract dilatation such as that reported in these 2 cases .
tacrolimus should be considered as an option for the management of severe uc with colonic dilatation to prevent toxic megacolon or as a bridging therapy to surgery , thereby avoiding high - risk emergency colectomy .
further controlled studies with larger numbers of patients should be performed to confirm our findings and to establish a standard for management for incorporating tacrolimus in the treatment of toxic megacolon .
we report 2 cases of ulcerative colitis ( uc ) with intestinal tract dilatation treated with tacrolimus . they were 53- and 64-year - old males , who had been admitted to local hospitals for increasing severity of their uc symptoms . 
 treatment for severe uc was immediately started , but both cases were refractory to corticosteroid therapy ; they were then transferred to our hospital . when they were referred to our hospital 
 , they had frequent bloody diarrhea , fever , severe abdominal pain , and even dilatation of the transverse colon on abdominal x - ray test . 
 they were treated with oral tacrolimus medication , and their symptoms improved immediately . 
 dilatation of the transverse colon was improved on plain x - ray at 2 weeks after starting therapy , and emergency colectomy could be avoided . 
 these 2 cases may suggest that tacrolimus is effective for uc with colonic dilatation as a rescue therapy .