Small intestinal bacterial overgrowth in patients with rheumatoid arthritis

Gastrointestinal Manifestations of Rheumatological Diseases

Rheumatological diseases (RDs) represent a diverse group of diseases that are inherited or related to environmental factors. RDs frequently affect the gastrointestinal (GI) tract, and gastroenterologists are often asked to evaluate patients with symptoms thought to represent an underlying or coexisting RD. GI manifestations of RDs vary based on the organ involved as well as the extent and duration of involvement. Although most manifestations of RD are nonspecific and not life-threatening, the chronicity and severity of symptoms can be debilitating and may lead to serious injury. This narrative review discusses the most common RD encountered by gastroenterologists: systemic lupus erythematosus, systemic sclerosis (scleroderma), dermatomyositis/polymyositis, rheumatoid arthritis, Sjögren syndrome, overlap syndromes, mixed connective tissue disease, Ehlers-Danlos syndromes, and other vasculitides. Each section begins with a brief overview of the condition, followed by a discussion of the etiopathophysiology, physical examination findings, GI manifestations, diagnostic tools (i.e., serologic, imaging, endoscopic, and functional), and treatment options.

Modulation of Inflammatory Arthritis in Mice by Gut Microbiota Through Mucosal Inflammation and Autoantibody Generation

OBJECTIVE

Observations of microbial dysbiosis in patients with rheumatoid arthritis (RA) have raised interest in studying microbial-mucosal interactions as a potential trigger of RA. Using the murine collagen-induced arthritis (CIA) model, we undertook this study to test our hypothesis that microbiota modulate immune responses leading to autoimmune arthritis.

METHODS

CIA was induced by immunization of mice with type II collagen (CII) in adjuvant on days 0 and 21, with arthritis appearing on days 23 and 24. Intestinal microbiota were profiled by 16S ribosomal RNA sequencing every 7 days during the course of CIA, and intestinal mucosal changes were evaluated on days 14 and 35. Then, microbiota were depleted either early (7 days before immunization) or late (day 21 after immunization) by administration of broad-spectrum antibiotics. Disease severity, autoantibody and systemic cytokine production, and intestinal mucosal responses were monitored in the setting of microbial reduction.

RESULTS

Significant dysbiosis and mucosal inflammation occurred early in CIA, prior to visible arthritis, and continued to evolve during the course of disease. Depletion of the microbiota prior to the induction of CIA resulted in an ~40% reduction in disease severity and in significantly reduced levels of serum inflammatory cytokines and anti-CII antibodies. In intestinal tissue, production of interleukin-17A (IL-17A) and IL-22 was delayed. Unexpectedly, microbial depletion during the late phase of CIA resulted in a >50% decrease in disease severity. Anti-CII antibodies were mildly reduced but were significantly impaired in their ability to activate complement, likely due to altered glycosylation profiles.

CONCLUSION

These data support a model in which intestinal dysbiosis triggers mucosal immune responses that stimulate T and B cells that are key for the development of inflammatory arthritis.

Restless legs syndrome--theoretical roles of inflammatory and immune mechanisms

Theories for restless legs syndrome (RLS) pathogenesis include iron deficiency, dopamine dysregulation and peripheral neuropathy. Increased prevalence of small intestinal bacterial overgrowth (SIBO) in controlled studies in RLS and case reports of post-infectious RLS suggest potential roles for inflammation and immunological alterations. A literature search for all conditions associated with RLS was performed. These included secondary RLS disorders and factors that may exacerbate RLS. All of these conditions were reviewed with respect to potential pathogenesis including reports of iron deficiency, neuropathy, SIBO, inflammation and immune changes. A condition was defined as highly-associated if there was a prevalence study that utilized an appropriate control group. Small case reports were recorded but not included as definite RLS-associated conditions. Fifty four diseases, syndromes and conditions have been reported to cause and/or exacerbate RLS. Of these, 38 have been reported to have a higher prevalence than age-matched controls, 9 have adequate sized reports and have general acceptance as RLS-associated conditions and 7 have been reported in case report form. Overall, 42 of the 47 RLS-associated conditions (89%) have also been associated with inflammatory and/or immune changes. In addition, 43% have been associated with peripheral iron deficiency, 40% with peripheral neuropathy and 32% with SIBO. Most of the remaining conditions have yet to be studied for these factors. The fact that 95% of the 38 highly-associated RLS conditions are also associated with inflammatory/immune changes suggests the possibility that RLS may be mediated or affected through these mechanisms. Inflammation can be responsible for iron deficiency and hypothetically could cause central nervous system iron deficiency-induced RLS. Alternatively, an immune reaction to gastrointestinal bacteria or other antigens may hypothetically cause RLS by a direct immunological attack on the central or peripheral nervous system.

Gastrointestinal and hepatic manifestations of rheumatoid arthritis

Rheumatoid arthritis (RA), characterized by inflammation of the synovium and surrounding structures, has a prevalence of 0.5-1%. Rheumatoid vasculitis (RV) is an inflammatory condition of the small- and medium-sized vessels that affects up to 5% of patients with RA with intestinal involvement in 10-38% of these cases. Clinically apparent RV of the gastrointestinal (GI) tract, while rare, is often catastrophic, resulting in ischemic ulcers and bowel infarction. Vasculitis of the colon may present as pancolitis clinically similar to ulcerative colitis. Rectal biopsies that include submucosal vessels are positive for vasculitis in up to 40% of cases. Abnormal esophageal motility in RA may result in heartburn and dysphagia. Chronic atrophic gastritis may be associated with hypergastrinemia and hypo- or achlorhydria, promoting small bowel bacterial overgrowth. RA is the most common cause of secondary amyloidosis with GI symptoms in 22% of affected patients. Although amyloid is usually found in the liver, it is rarely evident clinically. Felty's syndrome occurs in less than 1% of patients with RA and is characterized by neutropenia and splenomegaly. The liver may be involved with portal fibrosis or nodular regenerative hyperplasia. Liver histology is abnormal in 92% of RA patients at autopsy, although the changes are usually mild without associated hepatomegaly. Drug-induced liver disease may occur with aspirin, sulfasalazine, and methotrexate. Significant liver damage is rare if the drug is discontinued or the patient is properly monitored. RA can affect both the GI tract and the liver; changes are usually mild except with RV.

Clinical trial: the combination of rifaximin with partially hydrolysed guar gum is more effective than rifaximin alone in eradicating small intestinal bacterial overgrowth

BACKGROUND

Abnormal intestinal clearance is involved in the pathogenesis of small intestinal bacterial overgrowth (SIBO). It is known that partially hydrolysed guar gum affects intestinal motility. Eradication therapy of SIBO is based on antibiotic treatment: no data are available on the role of fibre supplementation in eradicating SIBO.

AIM

To assess whether the combination of partially hydrolysed guar gum and rifaximin is more effective than rifaximin alone in the treatment of SIBO.

METHODS

A 50 g-glucose breath test was given to 500 consecutive patients. Patients with a positive glucose breath test and predisposing conditions to SIBO entered into the study, and were randomized to receive rifaximin 1200 mg/day or rifaximin 1200 mg/day plus partially hydrolysed guar gum 5 g/day for 10 days. Patients completed a symptom questionnaire and glucose breath test both in basal condition and 1 month after withdrawal of therapy.

RESULTS

Seventy-seven patients had SIBO. Eradication rate of SIBO was 62.1% in the rifaximin group (both on per-protocol and intention-to-treat analyses), and 87.1% (per-protocol, P=0.017) and 85.0% (intention-to-treat, P=0.036) in the rifaximin-plus-partially hydrolysed guar gum group. Clinical improvement was observed in 86.9% and 91.1% of eradicated cases in rifaximin and rifaximin-plus-partially hydrolysed guar gum groups respectively (P=0.677).

CONCLUSION

The combination of rifaximin with partially hydrolysed guar gum seems to be more useful in eradicating SIBO compared with rifaximin alone.

Small intestinal bacterial overgrowth

Small intestinal bacterial overgrowth (SIBO) syndrome is characterized in its florid form by diarrhoea and weight loss. The most common underlying factors are dysmotility, small intestinal obstruction, blind or afferent loops. Small intestinal bacterial overgrowth can be diagnosed by: 1) culture of jejunum aspirate for bacterial counts, 2) 14C-D-xylose breath testing, 3) non-invasive hydrogen breath testing using glucose or lactulose or 4) 14C-glycocholic acid breath testing. The treatment usually consists of the eradication of bacterial overgrowth with repeated course of antimicrobials, correction of associated nutritional deficiencies and, when possible, correction of the underlying predisposing conditions.

A systematic review of diagnostic tests for small intestinal bacterial overgrowth

BACKGROUND

A growing number of studies seem to suggest that small intestinal bacterial overgrowth (SIBO) is a common clinical problem. Although various techniques are available to make this diagnosis, tradition has accepted small bowel aspirate (>10(5) cfu/ml) as a gold standard. In this systematic review, the validity of culture and other diagnostic testing for SIBO is evaluated.

METHODS

We performed a systematic review of the literature from 1966 to present using electronic databases (PubMed and OVID). Full paper review of those abstracts that fulfilled preset criteria was carried out to evaluate the validity of various tests in diagnosing SIBO. Finally, all papers were evaluated against published standards for studies on diagnostic testing.

RESULTS

Seventy-one papers met the criteria for detailed review. Studies were very heterogeneous with regards to patient populations, test definitions, sample size, and methods in general. Small bowel colony counts appeared elevated in most gastrointestinal diseases compared to controls. The traditional definition of >10(5) cfu/ml was usually indicative of stagnant loop conditions. Although, numerous diagnostic tests were studied, not even culture papers met the quality standards described by Reid et al. Breath testing and other diagnostic testing suffered therefore from the lack of a gold standard against which to validate in addition to the poor quality.

CONCLUSIONS

There is no validated diagnostic test or gold standard for SIBO. In this context, the most practical method to evaluate SIBO in studies at this time would be a test, treat, and outcome technique.

[Proposal of a questionnaire for the characterization of the prevalence of digestive symptoms in connective tissue diseases]

BACKGROUND

Connective tissue diseases may damage multiple organic systems, including digestive system. In this one, the degree of injury vary according to the associated disease. Despite the significant frequency of gastrointestinal involvement, there are few studies characterizing the prevalence of digestive symptoms in connective tissue diseases. Furthermore, most of the studies available are less detailed and based in personal experiences or reviews of records.

AIM

To establish a reliable list of gastrointestinal symptoms found in the progressive systemic sclerosis, rheumatoid arthritis, polymyositis/dermatomyositis, mixed connective tissue disease and systemic lupus erythematosus, through a medical interview and a predefined questionnaire of symptoms.

PATIENTS AND METHODS

There were studied 99 patients, 90% females, mean age 45 years. The whole group were composed of 35 rheumatoid arthritis, 26 progressive systemic sclerosis, 21 systemic lupus erythematosus, 12 polymyositis/dermatomyositis and 5 mixed connective tissue disease. Each patient was submitted to an interview with a well trained doctor and answered a structured questionnaire, containing 17 questions.

RESULTS

It was found a high prevalence of digestive symptoms in all five connective tissue diseases searched. Many of them were present in more than 50% of the patients. Called special attention the detection of some manifestations neglected by the literature like, for example, fecal incontinence. Also, disagreeing with other authors, was the finding of multiple gastrointestinal manifestations associated with rheumatoid arthritis. It was particularly surprising the occurrence of dysphagia in one third of the rheumatoid arthritis group.

CONCLUSIONS

The connective tissue diseases are usual causes of many gastrointestinal complaints. The use of an interview plus predefined questionnaire seems a very effective way to identify and characterize symptoms and is even sometimes able to uncover features unknown before. Finally, the lack of studies, specially updated studies, did not allow more comprehensive comparisons.

Modulation of immune function by dietary lectins in rheumatoid arthritis

Despite the almost universal clinical observation that inflammation of the gut is frequently associated with inflammation of the joints and vice versa, the nature of this relationship remains elusive. In the present review, we provide evidence for how the interaction of dietary lectins with enterocytes and lymphocytes may facilitate the translocation of both dietary and gut-derived pathogenic antigens to peripheral tissues, which in turn causes persistent peripheral antigenic stimulation. In genetically susceptible individuals, this antigenic stimulation may ultimately result in the expression of overt rheumatoid arthritis (RA) via molecular mimicry, a process whereby foreign peptides, similar in structure to endogenous peptides, may cause antibodies or T-lymphocytes to cross-react with both foreign and endogenous peptides and thereby break immunological tolerance. By eliminating dietary elements, particularly lectins, which adversely influence both enterocyte and lymphocyte structure and function, it is proposed that the peripheral antigenic stimulus (both pathogenic and dietary) will be reduced and thereby result in a diminution of disease symptoms in certain patients with RA.

Postoperative fatal intestinal necrosis after enalapril treatment in a patient with rheumatoid arthritis

The inappropriate use of antihypertensive medications may cause hypotensive responses associated with organ failure. We describe a patient who developed nonocclusive splanchnic ischemia leading to death following the administration of enalapril to treat postoperative hypertension. The mechanisms and consequences of refractory hypotension induced by angiotensin-converting enzyme inhibitors are discussed.

Enhanced jejunal production of antibodies to Klebsiella and other Enterobacteria in patients with ankylosing spondylitis and rheumatoid arthritis

OBJECTIVE

To measure gut immunity directly in jejunal fluid in patients with ankylosing spondylitis (AS) and rheumatoid arthritis (RA).

METHODS

Antibodies against three different Enterobacterias were measured in jejunal perfusion fluids (collected by a double balloon perfusion device) of 19 patients with AS, 14 patients with RA, and 22 healthy controls using enzyme linked immunosorbent assay.

RESULTS

The AS patients had significantly increased jejunal fluid concentrations of IgM, IgG, and IgA class antibodies against Klebsiella pneumoniae, and IgM and IgA class antibodies against Escherichia coli and Proteus mirabilis compared with healthy controls. When compared with the patients with RA, the AS patients had higher concentrations of IgA and IgG class antibodies only against K pneumoniae. The RA patients had higher IgM class antibody concentrations against all three studied Enterobacterias, when compared with the healthy controls, suggesting an enhanced mucosal immune response in these patients. A three month treatment with sulphasalazine did not decrease enterobacterial antibody concentrations in the 10 patients with AS.

CONCLUSION

There is strong direct evidence for an abnormal mucosal humoral immune response particularly to K pneumoniae in patients with AS.

Arthritis as the presenting symptom of diverticulitis

We describe a patient in whom peripheral arthritis was the presenting symptom of diverticulitis. The joint inflammation resolved only after treatment for the gastrointestinal disease. The pathogenesis, clinical aspects and management of this condition are discussed.

Role of endogenous enteric organisms in the reactivation of arthritis

Reactive arthritis is an acute form of arthritis apparently caused by a combination of bacterial infection and genetic influences. Recent experiments using an animal model suggest that certain bacterial cell wall polymers originating from endogenous enteric bacteria may be responsible for the condition.

Gastrointestinal motility disorders and bacterial overgrowth

Data on the relationship between small intestinal motility, absorption, and nutrition are sparse and incomplete. Yet, impaired motility is considered to be a plausible cause of bacterial overgrowth, which may have deleterious effects on digestion and absorption. This review discusses the scientific validity and clinical relevance of the concept that intestinal motor abnormalities are responsible for enteric bacterial overgrowth. Disorders associated with intestinal dysmotility and bacterial overgrowth, are illuminated, and concurrent studies of intestinal motility and microflora are focused on in detail. Moreover, practical considerations are given with regard to the clinical management of patients with bacterial overgrowth. Available data allow the conclusion to be drawn that impaired intestinal motility, as evidenced by attenuated migrating motor complex activity, results in bacterial overgrowth. The criteria for an intestinal motility disorder likely to result in bacterial overgrowth have been determined in patients with late radiation enteropathy, but studies in other clinical conditions are needed to establish general guidelines.

Correlation between infection and the onset of the giant cell (temporal) arteritis syndrome. A trigger mechanism?

OBJECTIVE

To assess for a correlation between infection and the onset of the giant cell (temporal) arteritis (GCA) syndrome.

METHODS

A matched case-control study design was used. Records of 100 patients with biopsy-proven GCA and 100 patients undergoing corrective surgery for hip fracture who did not have GCA were retrospectively reviewed. Non-GCA patients were sex-matched with GCA patients and were as old or older in age. The review period for GCA patients was up to 4 months before and during the occurrence of symptoms (median 2 months), and for non-GCA patients, it was up to 7 months before hip fracture. The prevalence of infection was compared using matched-pairs odds ratios and their 95% confidence intervals.

RESULTS

Infections were 3 times more likely to occur in GCA patients than in non-GCA patients (P < 0.05).

CONCLUSION

A correlation between the occurrence of infection and the onset of GCA is strongly suggested. We speculate that infection may act as a trigger mechanism in the pathogenesis of this syndrome.

Abnormal colonic microbial function in patients with rheumatoid arthritis

The aim of this study was to examine the microflora-associated characteristics (MACs) of faecal samples of patients with rheumatoid arthritis (RA) and to evaluate the actions of sulphasalazine (SASP) on these MACs. The conversion of cholesterol to coprostanol, the production of urobilinogen, the degradation of faecal tryptic activity (FTA) and of beta-aspartylglycine were measured in faecal samples from 19 patients treated with SASP and 21 patients not treated with this medication. A control group of 21 healthy subjects was sex- and age-matched with the untreated patients. The conversion of cholesterol to coprostanol showed a bimodal distribution. The frequency of high converters in patients without SASP treatment was higher than in healthy subjects (p < 0.05). Treatment with SASP markedly increased the FTA and reduced the urobilinogen values, as compared to the untreated patients (p < 0.05). Beta-aspartylglycine was not found in any faecal samples. The results indicate that patients with RA have an abnormal formation of coprostanol, which is ascribed to alterations in the function of the Eubacteria species. In patients with RA, SASP treatment induces disturbances in the metabolism of the microflora.