[Microscopic Colitis]

Microscopic colitis (MC) is still an underestimated cause of chronic, non-bloody watery diarrhea. It is typically manifested in elderly patients with a female predominance. The incidence of microscopic colitis has been increasing. The aetiology and pathophysiology remain unclear. Conditions associated with it include autoimmune diseases. There may be a genetic predisposition, as familial cases have been described. As implicated by the name microscopic colitis, the diagnosis is found by histological examination. There are mainly two subtypes, the lymphocytic colitis (LC) and the collagenous colitis (CC). Even if the condition's long-term course is benign, a chronic recurrent course of the symptoms is frequent. Due to the symptoms, there is an impairment of patient's health-related quality of life. A correct diagnosis and therapy is therefore mandatory. The aim of this paper is to create awareness for microscopic colitis.

Association of lymphocytic colitis and lactase deficiency in pediatric population

Characterized by colonic mucosa intraepithelial lymphocytosis, lymphocytic colitis is primarily an entity presented in the middle-aged to elderly patient population. Very few large series of lymphocytic colitis of childhood occurrence are available in the medical literature. Ten cases each of lymphocytic colitis and of colonic lymphocytosis of other diagnosis, all with duodenal disaccharidases analysis data, were collected from the files of our institution. The electronic medical records were reviewed and multiple variables were analyzed. The ten patients with lymphocytic colitis presented with diarrhea. Of these, three had abdominal pain. The age range was 2-18 years. Nearly all patients were Caucasian (90%) and 70% were female. Endoscopically, most had normal appearing colonic mucosa. Significant past medical history, family medical history and associated comorbidities included celiac disease, Down syndrome, juvenile arthritis and other autoimmune diseases. Interestingly, the most revealing observation was that the majority of cases (80%) were associated with lactase deficiency and, for the most part, gastrointestinal symptoms improved simply by treatment with Lactaid or avoidance of dairy products. This association is statistically significant. Our clinicopathological study indicates that the typical pediatric patient is a female Caucasian. A large of portion of the patients had associated lactase deficiency and improved on Lactaid supplement alone.

Impact of current smoking on the clinical course of microscopic colitis

BACKGROUND

Whether current smoking worsens the clinical course of microscopic colitis (MC) is unknown. The aim was to evaluate the impact of smoking on the clinical course of MC.

METHODS

One hundred and eighty-four patients (72% women; age, 62.4 ± 1.1 years) with MC (118 collagenous colitis (CC) and 66 lymphocytic colitis (LC) were evaluated (39 of them were current smokers). In all the patients, smoking habits and clinical data at presentation, response to therapy, and clinical relapses during follow-up were prospectively recorded. Risk factors for clinical relapse were studied in 160 patients after a mean follow-up of 28 ± 1 months. Cox regression analysis was used to adjust for confounding variables.

RESULTS

Age at diarrhea onset was 63.0 ± 1.4 years in nonsmokers and 50.4 ± 2.1 years in current smokers (P < 0.001). There was no significant influence of smoking habit on either clinical symptoms at diagnosis or clinical remission rate. Clinical relapse rate was 25.5% for CC and 29.6% for LC, with the mean relapse-free time 28.8 months (95% confidence interval, 26.3-31.4) for CC and 26.9 months (95% confidence interval, 26-30.3) for LC (P = 0.5). Multivariate analysis showed that age at diagnosis (<50 years versus others; adjusted hazard ratio, 2.8; 95% confidence interval, 1.3-6; P = 0.01) was associated with risk of relapse of CC but not LC. Current smoking was not an independent risk factor for either CC or LC relapse.

CONCLUSIONS

Active smokers developed MC more than a decade before nonsmokers. Age at diagnosis, but not smoking, was an independent risk factor of relapse in patients with CC.

Evolution of the incidence of collagenous colitis and lymphocytic colitis in Terrassa, Spain: a population-based study

BACKGROUND

Previous studies suggest an increase in the incidence rate of microscopic colitis in recent decades. The aim was to evaluate changes in the population-based incidence rate of microscopic colitis and its subtypes over time in Terrassa, Spain.

METHODS

This was a prospective study during the period 2004-2008, with a comparison of data from the period 1993-1997. The catchment area was a mixed rural-urban type, with nearly 290,000 inhabitants. All patients with nonbloody chronic diarrhea referred for a diagnostic colonoscopy were included. Multiple biopsy specimen samples were obtained when the macroscopic appearance of the colonic mucosa was normal to rule out microscopic colitis. Crude and adjusted incidence rates based on either the year of diagnosis or the date of onset of symptoms were calculated.

RESULTS

Forty patients with collagenous colitis (CC) and 32 with lymphocytic colitis (LC) were identified. The mean annual incidence of CC and LC based on the year of onset of symptoms was 2.6/10(5) inhabitants (95% confidence interval [CI], 1.9-3.3), and 2.2/10(5) inhabitants (95% CI, 1.5-3.0), respectively. Incidence rates for CC based on the year of onset of symptoms were significantly higher in the period 2004-2008 than in 1993-1997 (2.6 versus 1.1/10(5) ; P = 0.012). The increase in CC incidence was more marked in women (P = 0.047) than in men (P = 0.19).

CONCLUSIONS

The annual incidence of CC in Terrassa increased over time, mainly in women. Nevertheless, the rates were much lower than those observed in northern Europe, suggesting that there is a north-south difference in the incidence of microscopic colitis.

Lymphocytic colitis in a child with non-responsive celiac disease

In celiac disease, symptoms usually improve with strict adherence to diet. Some patients however do not show improvement despite of diet therapy. We here report a girl with non-responsive celiac disease whose diarrhea did not improve despite of a gluten free diet. A 12-year-old girl with recurrent diarrhea and failure to thrive was diagnosed with celiac disease. After six months of gluten-free diet her symptoms persisted. Adherence to diet was considered as correct and complete by a dietitian evaluation and by anti-endomysial antibodies that had become negative. Treatment with pancreatic enzymes, metronidazole or lactose free diet did not improve her symptoms. Colonoscopy was performed and lymphocytic colitis was diagnosed on histology from colonic biopsies. After mesalamine therapy diarrhea ceased, and weight and height z scores increased. Lymphocytic colitis, which is uncommonly seen in children compared to adults, should be considered in nonresponsive celiac disease in children.

Lymphocytic colitis: a clue to bacterial etiology

AIM

To find out the role of bacteria as a possible etiological factor in lymphocytic colitis.

METHODS

Twenty patients with histopathological diagnosis of lymphocytic colitis and 10 normal controls were included in this study. Colonoscopic biopsies were obtained from three sites (hepatic and splenic flexures and rectosigmoid region). Each biopsy was divided into two parts. A fresh part was incubated on special cultures for bacterial growth. The other part was used for the preparation of histologic tissue sections that were examined for the presence of bacteria with the help of Giemsa stain.

RESULTS

Culture of tissue biopsies revealed bacterial growth in 18 out of 20 patients with lymphocytic colitis mostly Escherichia coli (14/18), which was found in all rectosigmoid specimens (14/14), but only in 8/14 and 6/14 of splenic and hepatic flexure specimens respectively. In two of these cases, E coli was associated with proteus. Proteus was found only in one case, Klebsiella in two cases, and Staphylococcus aureus in one case. In the control group, only 2 out of 10 controls showed the growth of E coli in their biopsy cultures. Histopathology showed rod-shaped bacilli in the tissue sections of 12 out of 14 cases with positive E coli in their specimen's culture. None of the controls showed these bacteria in histopathological sections.

CONCLUSION

This preliminary study reports an association between E coli and lymphocytic colitis, based on histological and culture observations. Serotyping and molecular studies are in process to assess the role of E coli in the pathogenesis of lymphocytic colitis.

Seasonal pattern of onset in lymphocytic colitis

BACKGROUND

The etiology of lymphocytic colitis, a microscopic colitis syndrome, has remained elusive. Because 1) many infectious enteritides exhibit seasonal variability in incidence and 2) a few investigators have proposed some infectious mechanism in lymphocytic colitis, our aim was to determine if any variability in symptom onset existed among lymphocytic colitis patients diagnosed at our institution.

STUDY

We identified 71 nonduplicated, consecutive patients with lymphocytic colitis over a 4-year period using rigorous clinicopathologic inclusion criteria: 1) chronic watery diarrhea, 2) endoscopically normal colon, 3) no evidence for celiac sprue or drug-induced colitis, 4) diffuse colitis with increased intraepithelial lymphocytes of at least 10 lymphocytes per 100 epithelial cells, 5) evidence of surface epithelial damage, and 6) no significant neutrophilic infiltrates, architectural distortion of the mucosa, or subepithelial collagen deposits. The date of diagnosis was corrected for month of onset of symptoms.

RESULTS

The distribution of month of onset of symptoms showed a statistically significant (chi test of homogeneity, P = 0.0008) temporal variability and seasonal incidence pattern with excess cases during summer and fall and a paucity of cases during colder months.

CONCLUSIONS

To our knowledge, this is the first study to examine systematically and report a significant seasonal incidence pattern of lymphocytic colitis. Our observations may support a potential link to an infectious source in lymphocytic colitis.

Collagenous colitis and lymphocytic colitis: patient characteristics and clinical presentation

OBJECTIVE

Collagenous colitis and lymphocytic colitis (collectively known as microscopic colitis) are characterized by chronic diarrhea, normal endoscopic and radiologic findings, and typical findings on histologic examination of colonic tissue. The purpose of this study was to define the background characteristics of patients with microscopic colitis, as well as to present symptoms, coexistent autoimmune diseases, and a possible association with the use of non-steroidal anti-inflammatory drugs (NSAIDs) and ticlopidine.

MATERIAL AND METHODS

A retrospective chart review was carried out on all cases of collagenous colitis and lymphocytic colitis diagnosed at a single center from July 1992 to July 2002.

RESULTS

Of the 104 patients identified, 66 had collagenous colitis, 35 had lymphocytic colitis, and 3 were diagnosed with both disorders at different times. The mean age of patients was 64 years (26-88 years), with a female:male ratio of 4.8:1. The most common presenting symptoms were diarrhea (95%), weight loss (41%), abdominal pain (40%), fecal urgency (29%), and nocturnal stools (22%). Autoimmune disease was diagnosed in 29% of patients, 35% were using an NSAID, and 2% were using ticlopidine.

CONCLUSIONS

Collagenous colitis and lymphocytic colitis occur more often in females than in males, at a wide age range, with a mean in the seventh decade. Certain symptoms are characteristic, but are not specific to these disorders. There may be an association with the presence of a coexistent autoimmune disorder and the use of drugs such as NSAIDs.