Nils Hovdenak

Acute radiation proctitis : A sequential clinicopathologic study during pelvic radiotherapy

PURPOSE Rectal toxicity is often dose limiting during pelvic radiation therapy. This prospective study examined the sequential development and associations of clinical, endoscopic, and histopathologic rectal toxicity during ongoing radiation therapy. METHODS AND MATERIALS Thirty-three patients with nongastrointestinal pelvic carcinomas underwent proctoscopy with biopsy before radiation therapy, after 2 weeks treatment, and toward the end of the treatment course (6 weeks). Symptoms of acute toxicity were recorded, and endoscopic changes were graded. Histologic changes in the surface epithelium, glandular layer, and lamina propria were assessed using an ad hoc scoring system. Macrophage accumulation was evaluated in anti-CD68 stained sections. RESULTS Pretreatment endoscopy and biopsies were unremarkable. Clinical symptoms progressed toward the end of the treatment course. In contrast, endoscopic pathology was maximal at 2 weeks. Biopsies obtained during treatment exhibited atrophy of the surface epithelium, acute cryptitis, crypt abscesses, crypt distortion and atrophy, and stromal inflammation. Histologic changes, particularly those in the surface epithelium, were consistently more pronounced at 2 weeks than they were at 6 weeks. CONCLUSION In contrast to clinical symptoms, endoscopic changes stabilize and histologic changes regress from the 2nd to the 6th week of treatment. These results may have implications for the design and timing of prophylactic and therapeutic interventions to reduce radiation proctitis.

Familial diarrhea syndrome caused by an activating GUCY2C mutation.

BACKGROUND Familial diarrhea disorders are, in most cases, severe and caused by recessive mutations. We describe the cause of a novel dominant disease in 32 members of a Norwegian family. The affected members have chronic diarrhea that is of early onset, is relatively mild, and is associated with increased susceptibility to inflammatory bowel disease, small-bowel obstruction, and esophagitis. METHODS We used linkage analysis, based on arrays with single-nucleotide polymorphisms, to identify a candidate region on chromosome 12 and then sequenced GUCY2C, encoding guanylate cyclase C (GC-C), an intestinal receptor for bacterial heat-stable enterotoxins. We performed exome sequencing of the entire candidate region from three affected family members, to exclude the possibility that mutations in genes other than GUCY2C could cause or contribute to susceptibility to the disease. We carried out functional studies of mutant GC-C using HEK293T cells. RESULTS We identified a heterozygous missense mutation (c.2519G→T) in GUCY2C in all affected family members and observed no other rare variants in the exons of genes in the candidate region. Exposure of the mutant receptor to its ligands resulted in markedly increased production of cyclic guanosine monophosphate (cGMP). This may cause hyperactivation of the cystic fibrosis transmembrane regulator (CFTR), leading to increased chloride and water secretion from the enterocytes, and may thus explain the chronic diarrhea in the affected family members. CONCLUSIONS Increased GC-C signaling disturbs normal bowel function and appears to have a proinflammatory effect, either through increased chloride secretion or additional effects of elevated cellular cGMP. Further investigation of the relevance of genetic variants affecting the GC-C-CFTR pathway to conditions such as Crohns disease is warranted. (Funded by Helse Vest [Western Norway Regional Health Authority] and the Department of Science and Technology, Government of India.).

Loperamide Treatment of the Irritable Bowel Syndrome

The effect of loperamide was investigated in a double-blind, placebo-controlled study in 60 patients with irritable bowel syndrome (IBS). Active treatment was given in low dosage (4 mg nocte). The effect of treatment was assessed in clinical subgroups. In a group of patients with painless diarrhoea (n = 16) there was a highly significant improvement in stool frequency and consistency. In a group with alternating bowel habits and abdominal pain (n = 21) there was also a statistically significant improvement in stool frequency and consistency as well as significantly fewer painful days during loperamide treatment. Patients with alternating bowel habits and no pain (n = 12) experienced no symptomatic improvement, and patients with constipation (n = 9) generally felt worse on loperamide. No side effects were encountered. It is concluded that loperamide can be considered an alternative symptomatic treatment in some IBS patients whose main symptoms are painless diarrhoea or alternating bowel habits associated with abdominal pain.

High frequency of Coeliac disease among patients with autoimmune adrenocortical failure

Background: Coeliac disease (CD) is an autoimmune disease of the small intestine caused by gluten ingestion in genetically predisposed subjects. It can occur isolated or in combination with other autoimmune diseases. Autoimmune Addisons disease is frequently associated with other organ-specific autoimmune diseases. We have investigated the prevalence of CD among a large cohort of patients with autoimmune Addisons disease. Methods: Seventy-six patients (44 women) with Addisons disease, 52% of whom had polyendocrine failure, were recruited from a registry of organ-specific autoimmune diseases in Norway. All sera were analysed for antibodies against gliadin (AGA), endomysium (EMA) and tissue transglutaminase (tTG). Patients with positive EMA and/or anti-tTG were offered endoscopy. The human leucocyte antigen (HLA) class II genotypes were determined. Results: Five patients had antibodies against both endomysium and tissue transglutaminase. In these five patients, CD was verified by biopsy. One patient had known CD prior to the study. All six patients with CD carried the CD-associated HLA haplotype DR3-DQ2. The total prevalence of CD was 7.9%. Conclusion: CD is frequently associated with Addisons disease. The risk of developing CD seems to be higher than can be explained by the common DR3-DQ2 association alone. It is often asymptomatic or associated with unspecific symptoms. Addison patients should be screened for the presence of CD on a regular basis.

Clinical significance of increased gelatinolytic activity in the rectal mucosa during external beam radiation therapy of prostate cancer

PURPOSE Rectal toxicity (proctitis) is a dose-limiting factor in pelvic radiation therapy. Mucosal atrophy, i.e., net extracellular matrix degradation, is a prominent feature of radiation proctitis, but the underlying mechanisms are not known. We prospectively examined changes in matrix metalloproteinase (MMP)-2 and MMP-9 (gelatinase A and B) in the rectal mucosa during radiation therapy of prostate cancer, as well as the relationships of these changes with symptomatic, structural, and cellular evidence of radiation proctitis. METHODS AND MATERIALS Seventeen patients scheduled for external beam radiation therapy for prostate cancer were prospectively enrolled. Symptoms of gastrointestinal toxicity were recorded, and endoscopy with biopsy of the rectal mucosa was performed before radiation therapy, as well as 2 and 6 weeks into the treatment course. Radiation proctitis was assessed by endoscopic scoring, quantitative histology, and quantitative immunohistochemistry. MMP-2 and MMP-9 were localized immunohistochemically, and activities were determined by gelatin zymography. RESULTS Symptoms, endoscopic scores, histologic injury, and mucosal macrophages and neutrophils increased from baseline to 2 weeks. Symptoms increased further from 2 weeks to 6 weeks, whereas endoscopic and cellular evidence of proctitis did not. Compared to pretreatment values, there was increased total gelatinolytic activity of MMP-2 and MMP-9 at 2 weeks (p = 0.02 and p = 0.004, respectively) and 6 weeks (p = 0.006 and p = 0.001, respectively). Active MMP-2 was increased at both time points (p = 0.0001 and p = 0.002). Increased MMP-9 and MMP-2 at 6 weeks was associated with radiation-induced diarrhea (p = 0.007 and p = 0.02, respectively) and with mucosal neutrophil infiltration (rho = 0.62). CONCLUSIONS Pelvic radiation therapy causes increased MMP-2 and MMP-9 activity in the rectal mucosa. These changes correlate with radiation-induced diarrhea and granulocyte infiltration and may contribute to abnormal connective tissue remodeling in radiation proctitis.

Time patterns of changes in biomarkers, symptoms and histopathology during pelvic radiotherapy

Acute radiation proctitis was evaluated before, during and after radiotherapy (RT) for prostate cancer. The main aims of the study were to examine changes related to the increasing radiation dose, and identify surrogate markers of gastrointestinal (GI) reaction to radiation. Twenty consecutive prostate cancer patients scheduled for 7 weeks of conformal RT were prospectively included in a longitudinal study assessing symptoms, inflammation in rectal mucosa biopsies, and blood and stool samples at four time points (before RT and 2, 6 and 11 weeks after start of RT). Blood samples were examined for acute phase response-related markers, fatty acids (FAs), vitamin E and leukotriene B4 (LTB4). Lactoferrin, calprotectin and S100A12 were measured in stool samples and FAs in biopsies from rectal mucosa. The increase in histopathological inflammation reached a maximum 2 weeks after start of RT. Symptoms of GI toxicity increased with higher radiation dose and had not returned to pre-treatment level 4 weeks after RT. Lactoferrin concentrations in stool increased significantly at week 6. Significant decreases of vitamin E, leukocyte count, hemoglobin and some groups of FAs were discovered, while a few FAs increased significantly during the study period. Time courses vary between the selected indicators of acute radiation proctitis. The biopsy grading of inflammatory changes were most intense 2 weeks into the treatment period while symptoms continued to increase until week 6. Lactoferrin in stool samples could be a non-invasive marker of GI inflammation during RT. A transient decrease in vitamin E and some FAs during RT warrants further studies.

Faecal calprotectin and lactoferrin as markers of acute radiation proctitis: a pilot study of eight stool markers.

Background: Non-invasive diagnostic tools to evaluate the severity of acute, radiation-induced proctitis are not readily available. The faecal excretion of eight markers of gut inflammation was therefore examined. Five proteins and three lipid derivates were analysed in sequential stool samples taken before and during radiation therapy. Methods: Stool samples from 15 patients with prostate cancer scheduled for radiation therapy were examined. Pretreatment and in-treatment samples (2nd and 6th weeks) were measured by enzyme-linked immunosorbent assay (ELISA) (calprotectin, lactoferrin, transferrin, leukotriene B4, prostaglandin E2, thromboxane B2 and TNFα) or nephelometry (α1-antitrypsin). Results: Calprotectin and lactoferrin concentrations increased significantly during radiation treatment (P = 0.0005 and P = 0.019). Transferrin was detected in only 9 out of 45 samples. There were no changes in tumour necrosis factor α (TNFα), leukotriene B4, prostaglandin E2 and thromboxane B2 during treatment. α1-antitrypsin could not be detected in any sample. Conclusions: This study indicates that faecal calprotectin and lactoferrin concentrations could be markers of acute, radiation-induced proctitis. Patient compliance and stability of the markers make this a promising method for clinical research. Eicosanoids could be measured in stool samples, but the concentrations did not increase with increasing radiation dose.

Low-Dose Antacids or Cimetidine for Duodenal Ulcer?

In a double-blind, randomized, multicenter trial 150 consecutive outpatients with endoscopically verified duodenal ulcer were treated with either a low-dose antacid regimen (1 tablet q.i.d.; acid-neutralizing capacity, 120 mmol/day), or cimetidine (800 mg nocte). After 4 wk of treatment control gastroscopy showed ulcer healing in 54 of 76 patients (71.1%) in the antacid group, as compared with 58 of 74 patients (78.4%) in the cimetidine-treated group. The difference in healing rate of 7.3% (95% confidence interval, -6.5% to +21.1%) was not statistically significant. The symptomatic effect, measured as number of days and nights with ulcer pain, was also quite similar in the two treatment groups. However, the number of days with pain was significantly lower in the first week of treatment in the antacid group (p less than 0.01). Thus, the efficacy of a low-dose antacid tablet regimen approximated that of cimetidine (800 mg nocte) in the treatment of duodenal ulcer patients.

Profiles and Time Course of Acute Radiation Toxicity Symptoms during Conformal Radiotherapy for Cancer of the Prostate

Symptoms of gastrointestinal toxicity are dose-limiting for pelvic radiotherapy (RT). Existing toxicity registrations (RTOG/EORTC) are helpful in defining maximal tolerated doses, but tend to underestimate the total toxicity burden by excluding several minor complaints. We have applied a more detailed and quantitative recording of symptoms and related these scores to RT-induced endoscopic and histopathologic changes. Prevalence and severity of specific toxicity symptoms were recorded before, during (weeks 2 and 6) and 2 and 8 weeks after RT in 96 patients undergoing external beam RT for localized prostate cancer. RTOG/EORTC acute toxicity and ad hoc total toxicity scores (TTS) were recorded. TTS scores were calculated by adding scores based on visual analog scale (VAS) grading of individual symptoms. Fifty of the patients also underwent sequential proctoscopy with mucosal biopsy. Individual symptoms increased, but differed in prevalence and intensity during and after RT. TTS increased during the entire treatment course in spite of normalizing histopathologic and endoscopic changes from week 2 onwards. Twenty-seven patients had no RTOG/EORTC toxicity, four had grade 3 and none had grade 4 toxicity. All patients with grade 0 had increased TTS. Thus, TTS appeared more sensitive than RTOG/EORTC scoring. The study demonstrates that multiple toxicity symptoms contribute to total toxicity in response to pelvic RT. TTS is a feasible and sensitive method for detecting and quantifying acute toxicity and unveils morbidity which remains hidden with the RTOG/EORTC score system. The development and timing of symptoms may give clues to pathogenesis, treatment, and prophylaxis.

Colonic Mucosal Epigenome and Microbiome Development in Children and Adolescents.

Epigenetic and microbiome changes during pediatric development have been implicated as important elements in the developmental origins of inflammatory bowel diseases (IBDs) including Crohns disease (CD) and ulcerative colitis (UC), which are linked to early onset colorectal cancer (CRC). Colonic mucosal samples from 22 control children between 3.5 and 17.5 years of age were studied by Infinium HumanMethylation450 BeadChips and, in 10 cases, by 454 pyrosequencing of the bacterial 16S rRNA gene. Intercalating age-specific DNA methylation and microbiome changes were identified, which may have significant translational relevance in the developmental origins of IBD and CRC.