PubMed Health⌕ Search

Biomedical subjects

Bruce E Sands

Publications and source records attributed to Bruce E Sands.

27 records · Page 2Linked to original sources

Guidelines for immunizations in patients with inflammatory bowel disease.

During the past 2 decades, medical therapy for Crohn's disease (CD) and ulcerative colitis (UC) has grown to incorporate a variety of immunesuppressing agents. At the same time, basic insights into the aberrant mucosal immune response underlying inflammatory bowel disease (IBD) have expanded dramatically. The interplay of host susceptibility to infection and the safety and efficacy of immunization for vaccine-preventable diseases has been explored in other immune-mediated disease states but only rarely in IBD. The purpose of this review is to formulate best-practice recommendations for immunization in children and adults with IBD by considering the effects of the IBD disease state and its treatments on both the safety and efficacy of immunization. To do so, we first considered the routine recommendations for immunization of children, adults and distinct populations at increased risk for vaccine-preventable disease. Because it was rarely possible to examine direct data on safety and efficacy of immunization in IBD populations, we relied to a large extent upon extrapolation from similar populations and from knowledge of basic mechanisms. The literature suggests that efficacy of immunization may be diminished in some patients whose immune status is compromised by immune suppression. However, except for live agent vaccines, most immunizations may be safely administered to patients with IBD even when immune compromised. Conversely, protection against vaccine-preventable illness may be of even greater benefit to those at risk for morbid or lethal complications of infections because of an immune compromised state. We conclude that for most patients with IBD, recommendations for immunization do not deviate from recommended schedules for the general population.

Adolescent↗

Occurrence of colon ischemia in relation to irritable bowel syndrome.

OBJECTIVE: In November 2000, alosetron HCl (Lotronex), a treatment for irritable bowel syndrome (IBS), was removed from the U.S. market in part because of the occurrence of colon ischemia in treated patients. Since the relation between colon ischemia and IBS is poorly understood, we evaluated the incidence of colon ischemia among people with and without IBS. METHODS: Using medical claims data from a large health care organization in the United States, we identified 87,449 people with an IBS diagnosis between January 1995 and December 1999. We calculated age- and sex-specific incidence rates in the general population and in IBS patients. RESULTS: There were 740 cases of colon ischemia during 8.5 million person-years of observation in 5.4 million persons. The crude incidence rate was 42.8 cases per 100,000 person-years for IBS patients. By comparison, the incidence rate was 7.2 per 100,000 person-years in the general population. After adjustment for age, sex, and calendar year, the incidence of colon ischemia in people with IBS was 3.4 times higher than in persons without (95% CI 2.6-4.5). CONCLUSIONS: Rates of colon ischemia among patients carrying a diagnosis of IBS are substantially higher than in the general population. Colon ischemia, though unusual in IBS patients, may nonetheless constitute a distinct part of the IBS natural history. Alternatively, it may be a consequence of therapy, or a manifestation of other bowel pathology that is sometimes confused with IBS.

Adult↗

Risk factors for colon ischemia.

BACKGROUND: To identify predictors of colon ischemia, we examined demographic and clinical characteristics of patients, as well as their prior health care utilization. METHODS: Using insurance data, we identified 700 persons at least 20-yr old with presumed colon ischemia between 1995 and 1999, and 6,440 controls. Case identification was based on diagnosis and procedure codes in insurance claims for which we used a previously reported, validated algorithm. We ascertained preceding medical diagnoses and the use of drugs and health services from the insurance claims files. RESULTS: Patients with colon ischemia were nearly three times as likely to have IBS than controls. A history of nonspecific colitis, lower gastrointestinal tract hemorrhage, systemic rheumatologic disorders, and ischemic heart disease in the preceding 6 months, and abdominal surgery in the past month were also much more common in colon ischemia cases than controls. Use of a drug to treat diarrhea was strongly associated with risk. The most prevalent risk factor for colon ischemia was the use of drugs with a side effect of constipation, found in one-third of cases and one in nine controls. Cases had seen physicians, particularly gastroenterologists, much more commonly in the preceding 6 months than had controls. CONCLUSIONS: Clinically evident colon ischemia arises preferentially in persons with prior abdominal complaints, many of whom carry a diagnosis of IBS. Drugs that reduce bowel motility may constitute a widespread and potentially avoidable risk factor. The frequency of preceding doctor visits, without a specific diagnosis, suggests that colon ischemia may have a prolonged subacute presentation.

Adult↗

Why do anti-tumor necrosis factor antibodies work in Crohn's disease?

Anti-tumor necrosis factor (TNF) antibodies are powerful therapeutic agents for the treatment of Crohn's disease. TNF has diverse proinflammatory effects within the intestinal mucosa and is a pivotal cytokine in the inflammatory cascade. Although anti-TNF antibodies exert a variety of anti-inflammatory effects by neutralizing the cytokine, these agents vary in their efficacy. Recent data suggest that the ability to bind transmembrane TNF is a key property necessary for efficacy. Transmembrane binding of TNF effects apoptosis of T cells, thereby alleviating a fundamental defect in Crohn's disease in the regulation of T cell populations.

Animals↗

Incidence of colonic ischemia, hospitalized complications of constipation, and bowel surgery in relation to use of alosetron hydrochloride.

OBJECTIVE: Alosetron hydrochloride (Lotronex), a potent selective 5-hydroxytryptamine(3) receptor antagonist, was approved in February, 2000 in the United States for the treatment of diarrhea-predominant irritable bowel syndrome (IBS) in women. Marketing was suspended in November, 2000, after reports of colonic ischemia and serious complications of constipation. We sought to compare the incidence of colonic ischemia, hospitalized complications of constipation, and bowel surgery among alosetron users and a cohort of patients with IBS who did not use alosetron. METHODS: We sought outcomes of colonic ischemia, hospitalized complications of constipation, and bowel surgery in 3,631 Lotronex users and 2,480 comparison IBS subjects using diagnoses, procedures, and drugs recorded in the UnitedHealthcare insurance claims database, and validated these by chart review. The initial assessment was to last for 3 yr beginning with the start of alosetron treatment and was to include 10,000 Lotronex users; however, the observation period ended by December 31, 2000, after suspension of marketing. RESULTS: There were 3631 alosetron users among members of UnitedHealthcare from March through December, 2000, and we identified 2480 comparison IBS-only patients; follow-up time averaged about 5 months in both groups. There were no instances of colonic ischemia in either cohort. Thirty instances of bowel surgery occurred, giving rates of 10.2/1000 person-yr in the alosetron cohort and 11.8/1000 person-yr in the IBS/no alosetron cohort. There were three cases of hospitalized complications of constipation. The incidence rates were essentially the same in alosetron users (1.24/1000 person-yr) and in IBS patients with no alosetron use (0.92/1000 person-yr). CONCLUSIONS: Alosetron users did not differ from IBS patients not using alosetron in the incidence of bowel surgery or hospitalized complications of constipation; there were no cases of colonic ischemia. The statistical upper limit of colonic ischemia rates in alosetron users was 2.28/1000 person-yr. Because of the market withdrawal, the size of the cohort and the duration of follow-up were smaller than originally planned; consequently, the statements about the safety of alosetron were necessarily limited. On June 7, 2002, the Food and Drug Administration approved alosetron for reintroduction in the U.S. market for women with severe diarrhea-related IBS.

Adolescent↗

Risk of early surgery for Crohn's disease: implications for early treatment strategies.

OBJECTIVES: In this study we aimed to define the rate of early surgery for Crohn's disease and to identify risk factors associated with early surgery as a basis for subsequent studies of early intervention in Crohn's disease. METHODS: We assembled a retrospective cohort of patients with Crohn's disease diagnosed between 1991 and 1997 and followed for at least 3 yr, who were identified in 16 community and referral-based practices in New England. Chart review was performed for each patient. Details of baseline demographic and disease features were recorded. Surgical history including date of surgery, indication, and procedure were also noted. Risk factors for early surgery (defined as major surgery for Crohn's disease within 3 yr of diagnosis, exclusive of major surgery at time of diagnosis) were identified by univariate analysis. Multiple logistic regression was used to identify independent risk factors. RESULTS: Of 345 eligible patients, 69 (20.1%) required surgery within 3 yr of diagnosis, excluding the 14 patients (4.1%) who had major surgery at the time of diagnosis. Overall, the interval between diagnosis and surgery was short; one half of all patients who required surgery underwent operation within 6 months of diagnosis. Risk factors identified by univariate analysis as significantly associated with early surgery included the following: smoking; disease of small bowel without colonic involvement; nausea and vomiting or abdominal pain on presentation; neutrophil count; and steroid use in the first 6 months. Disease localized to the colon only, blood in the stool, use of 5-aminosalicylate, and lymphocyte count were inversely associated with risk of early surgery. Logistic regression confirmed independent associations with smoking as a positive risk factor and involvement of colon without small bowel as a negative risk factor for early surgery. CONCLUSIONS: The rate of surgery is high in the first 3 yr after diagnosis of Crohn's disease, particularly in the first 6 months. These results suggest that improved risk stratification and potent therapies with rapid onset of action are needed to modify the natural history of Crohn's disease.

Adolescent↗

Treatment with a broad-spectrum cephalosporin versus piperacillin-tazobactam and the risk for isolation of broad-spectrum cephalosporin-resistant Enterobacter species.

Receipt of a broad-spectrum cephalosporin is a strong risk factor for isolation of broad-spectrum cephalosporin-resistant Enterobacter species, and yet the risk from other broad-spectrum beta-lactams hydrolyzed by group 1 beta-lactamases has not been well characterized. We compared the risk conferred by broad-spectrum cephalosporins to that conferred by piperacillin-tazobactam, alone or in combination with an aminoglycoside or a fluoroquinolone. A retrospective cohort was monitored from treatment onset until a broad-spectrum cephalosporin-resistant Enterobacter strain was isolated or the patient was discharged. There were 447 patients in the piperacillin-tazobactam group and 2,341 patients in the broad-spectrum cephalosporin group. Groups were similar in age (mean, 62.5 years). The piperacillin-tazobactam group had a smaller percentage of men (32% versus 44%, P < 0.001) and a lower rate of intensive care unit stay (25% versus 38%, P < 0.001) but a higher rate of surgery (41% versus 26%, P < 0.001). Groups differed in the distribution of comorbidities. Resistant Enterobacter strains were isolated from 62 patients, 2% in each group (hazard ratio [RR] = 1.02 [P = 0.95]). In multivariable analysis, risk was similar among treatment groups (RR = 0.71 [P = 0.32]). Intensive care unit stay and surgery were associated with increased risk (RR = 4.53 [P < 0.001] and RR = 1.97 [P = 0.015], respectively), fluoroquinolones were protective (RR = 0.24 [P = 0.003]), and aminoglycosides did not affect risk (RR = 0.98 [P = 0.95]). The protective effect of fluoroquinolones against isolation of broad-spectrum cephalosporin-resistant Enterobacter spp. and the equivalence in risk associated with piperacillin-tazobactam and broad-spectrum cephalosporins may have important clinical and epidemiologic implications.

Anti-Bacterial Agents↗

Effects of growth hormone secretion on body composition in patients with Crohn's disease.

Crohn's disease is a multisystem disorder characterized by chronic intestinal inflammation. Accumulation of mesenteric fat occurs in patients with Crohn's disease, although the mechanisms underlying site-specific changes in adipose deposition are unclear. To investigate whether there are alterations in site-specific adipose deposition in patients with Crohn's disease and to determine hormonal influences that may underlie such changes, we investigated body composition and serum hormone levels in 20 men with Crohn's disease (mean age, 45 +/- 2 yr) and 20 age-, gender-, and body mass index-matched normal controls (mean age, 43 +/- 3 yr). None of the Crohn's patients was receiving glucocorticoid therapy. Subjects underwent hourly GH sampling for 12 h beginning at 2000 h and fasting serum IGF-I and testosterone measurements. Body composition was assessed by quantitative computed tomography of the abdomen and bioelectrical impedance analysis. In the Crohn's disease and control subjects, mean serum GH levels were 1.07 +/- 0.2 and 1.7 +/- 0.2 ng/ml (P = 0.06), serum IGF-I levels were 162.7 +/- 10.5 and 194.8 +/- 15.7 ng/ml (P = 0.1), and serum testosterone levels were 489 +/- 33 and 514 +/- 38 ng/ml (P = NS), respectively. Percentage body fat was significantly higher in the Crohn's patients (21 +/- 0.8% vs. 17.7 +/- 0.9%, respectively; P = 0.013). Intraabdominal fat (IAF) was significantly higher in the Crohn's subjects vs. controls (115 +/- 11 vs. 69 +/- 7 cm(2), respectively; P = 0.001). The ratio of intraabdominal to total body fat was higher in the Crohn's subjects than in the controls (0.4 +/- 0.1 vs. 0.3 +/- 0.1, respectively; P = 0.025). Subcutaneous fat area was similar in the two groups. IAF was higher in Crohn's patients even when controlling for testosterone and mean serum GH. Mean serum GH contributed independently to the differences in IAF (P = 0.001). The ratio of IAF to total body fat remained higher in the Crohn's subjects when controlling for serum testosterone, but was no longer significant in a model that also included IGF-I and mean serum GH. GH levels contributed independently to the differences in the intraabdominal to total body fat ratio (P = 0.02). In the Crohn's patients, serum GH correlated negatively with intraabdominal and total body fat and the ratio of intraabdominal to total body fat. Crohn's disease is associated with an increase in central fat accumulation, with more IAF and a higher ratio of intraabdominal to total body fat compared with controls. Although serum GH levels were similar in the two groups, GH contributed significantly to the abdominal fat measurements. These data show that GH has an important role in modulating visceral fat distribution in patients with Crohn's disease.

Adipose Tissue↗