Intestinal eosinophils: multifaceted roles in tissue homeostasis and disease.

Intestinal eosinophils are largely considered to be one of the central immune effector cells during helminth infection and disorders such as eosinophilic oesophagitis and food allergies. Given the abundance of these cells present in the gastrointestinal tract at homeostasis, emerging studies now reveal novel roles for eosinophils in the development and regulation of immunity, and during tissue repair. In addition, the identification of distinct eosinophil subsets indicates that we must consider the heterogeneity of these cells and how they differentially participate in mucosal immunity at steady state and during disease. Here, we summarise the literature on intestinal eosinophils, and how they contribute to mucosal homeostasis through immune regulation and interactions with the microbiome. We then explore the divergent roles of eosinophils in the context of eosinophilic gastrointestinal disorders and during helminth infection, whereby we discuss key observations and differences that have emerged from animal models and human studies. Lastly, we consider the possible interactions of eosinophils with the enteric nervous system, and how this represents an exciting area for future research which may inform future therapeutic targets.

Neutrophilic urticarial dermatosis: a novel association with poststreptococcal rheumatic disease.

Neutrophilic urticarial dermatosis (NUD), a particular clinical and histological entity, can provide a strong pointer to underlying systemic disease, most frequently rheumatological diseases. We report the first case of NUD in association with a post-streptococcal rheumatic disease, with symptoms including recurrent sore throat, raised antistreptolysin O titre, persistent transient urticaria, polyarthralgia, rheumatic mitral valve disease and Jaccoud arthropathy. Histologically, NUD is characterized by an intense superficial and deep neutrophilic interstitial and perivascular infiltrate, without significant oedema or blood vessel damage. These neutrophils may have a tendency to concentrate along the basement membrane and extend into the epidermis, hair follicles, sebaceous glands and sweat glands (a feature termed 'neutrophilic epitheliotropism'). Clinicians should remain cognizant of NUD, and in particular its frequent association with an underlying inflammatory disorder.

Management of septic arthritis: a systematic review.

OBJECTIVE: To evaluate the existing evidence on the diagnosis and management of septic arthritis in native joints. DESIGN: Systematic review. DATA SOURCES: Cochrane Library, Medline, Embase, National Electronic Library for Health, reference lists, national experts. REVIEW METHODS: Systematic review of the literature with evaluation of the methodological quality of the selected papers using defined criteria set out by the Clinical Effectiveness and Evaluation Unit of the Royal College of Physicians. RESULTS: 3291 citations were initially identified. Of these, 189 full text articles were identified for potential selection. Following review of these full text articles, 80 articles were found to fulfil the inclusion criteria and were included in the final list. Conclusions were drawn on the diagnosis, investigation and management of septic arthritis. DISCUSSION: Little good quality evidence exists to guide the diagnosis and management of septic arthritis. Overall, no investigation is more reliable in the diagnosis of septic arthritis than the opinion of an experienced doctor. Aspiration and culture of synovial fluid is crucial to the diagnosis, but measurement of cell count is unhelpful. Antibiotics are clearly required for a prolonged period, but there are no data to indicate by which route or for how long. Key unanswered questions remain surrounding the medical and surgical management of the infected joint.

Management of septic arthritis: a systematic review.

OBJECTIVE: To evaluate the existing evidence on the diagnosis and management of septic arthritis in native joints. DESIGN: Systematic review. DATA SOURCES: Cochrane Library, Medline, Embase, National Electronic Library for Health, reference lists, national experts. REVIEW METHODS: Systematic review of the literature with evaluation of the methodological quality of the selected papers using defined criteria set out by the Clinical Effectiveness and Evaluation Unit of the Royal College of Physicians. RESULTS: 3291 citations were initially identified. Of these, 189 full text articles were identified for potential selection. Following review of these full text articles, 80 articles were found to fulfil the inclusion criteria and were included in the final list. CONCLUSIONS: were drawn on the diagnosis, investigation and management of septic arthritis. DISCUSSION: Little good quality evidence exists to guide the diagnosis and management of septic arthritis. Overall, no investigation is more reliable in the diagnosis of septic arthritis than the opinion of an experienced doctor. Aspiration and culture of synovial fluid is crucial to the diagnosis, but measurement of cell count is unhelpful. Antibiotics are clearly required for a prolonged period, but there are no data to indicate by which route or for how long. Key unanswered questions remain surrounding the medical and surgical management of the infected joint.

Analysis of predictors of success in the MRCP (UK) PACES examination in candidates attending a revision course.

OBJECTIVE: To determine factors that predict success of candidates taking a revision course in preparation for the MRCP (UK) PACES (practical assessment of clinical examination skills) examination. DESIGN: A questionnaire survey of candidates attending a PACES revision course. Results were correlated with subsequent pass lists published by the Colleges of Physicians. SETTING AND SUBJECTS: Candidates attending courses in June and October 2002. In total, 523 candidates completed questionnaires, evenly balanced between UK and overseas graduates. RESULTS: Of 483 candidates who took the examination immediately after the course, 219 (45.3%) passed. UK graduates were more likely to pass (67.0%) than overseas graduates (26.2%) (p = 0.003, odds ratio 5.72). For UK graduates, pass rates were higher for white candidates (73%) than for ethnic minorities (56%) (p = 0.012, OR 2.15) and for those who passed at the first attempt in the MRCP (UK) part 2 written paper (p = 0.003, OR 2.90). For overseas graduates, those who had been qualified for less than eight years were more likely to pass (p = 0.001, OR 2.78). More overseas (45.7%) than UK (30.8%) graduates were confident that they would pass, but confidence did not predict success. CONCLUSION: Among candidates taking a revision course, UK graduates are more likely to pass the PACES examination than non-UK graduates. Ethnic minority UK graduates seem to have a significantly poorer success rate, although this requires confirmation in an independent sample. If confirmed, these differences merit further investigation to assess whether they reflect genuine differences in ability.

Autoantibodies against granulocyte-macrophage colony stimulating factor and interleukin-3 are rare in patients with Felty's syndrome.

OBJECTIVES: Antibodies against granulocyte colony stimulating factor are frequently found in patients with Felty's syndrome (FS). In this study, we examined the prevalence of antibodies against two other granulopoietic cytokines: granulocyte-macrophage colony stimulating factor (GM-CSF) and interleukin-3 (IL3). METHODS: Sera of 32 patients with FS, 20 normocytic patients with rheumatoid arthritis (RA), and 72 healthy individuals were screened for the presence of antibodies against GM-CSF and IL3 by ELISA and bioassays, using the human erythroleukaemia cell line TF-1. RESULTS: In two of the 32 patients with FS, antibodies to GM-CSF and IL3 were detectable by ELISA. Binding anti-GM-CSF antibodies were also detected in one of the 72 healthy controls, while in another healthy subject and in one of the patients with normocytic RA, anti-IL3 antibodies were present. Serum from one of the two patients with FS who tested positive for anti-IL3 and anti-GM-CSF antibodies by ELISA showed strong neutralising capacity to the biological effect of IL3, but not to GM-CSF in vitro. Patients with FS had significantly higher serum levels of GM-CSF (median; 2.82 pg/mL; interquartile range 2.64-3.19 pg/mL) compared with patients with RA (2.52 pg/mL; 2.28-2.72 pg/mL; p = 0.012) and healthy controls (2.23 pg/mL; 2.04-2.52; p<0.001). In addition, serum levels of IL3 in patients were significantly higher in FS (10.05 pg/mL; 8.94-11.98) compared with controls (4.79 pg/mL; 3.72-7.22; p<0.001), but not compared with RA patients (9.52 pg/mL; 8.32-10.42; p = 0.17). CONCLUSIONS: Antibodies to GM-CSF and IL3 are rare in patients with FS and RA and in healthy subjects. In individual patients with FS, the presence of neutralising anti-IL3 antibodies may contribute to the development of cytopenia.

Major histocompatility complex haplotypic associations in Felty's syndrome and large granular lymphocyte syndrome are secondary to allelic association with HLA-DRB1 *0401.

OBJECTIVE: To investigate the role of HLA class I in susceptibility to Felty's syndrome (FS) and large granular lymphocyte (LGL) syndrome. METHODS: Fifty caucasoid FS patients, and 55 patients with LGL syndrome, of whom 26 had arthritis and 29 did not, were studied. Complete HLA class I and HLA-DR typing including, where relevant, DRB1*04 subtyping was carried out by molecular methods. Comparison was made with 78 unselected healthy caucasoid controls and a further 29 DRB1*0401+ individuals. RESULTS: A significant association was found between HLA-A*02 and FS [odds ratio (OR) 3.9, 95% confidence interval (95% CI) 1.8-8.4, P = 0.0004]. At the B locus, there was an association between B*44 and LGL with arthritis [OR 3.5 (1.3-9.2), P = 0.01]. For HLA-Cw*0501, there was an association with FS [OR 4 (1. 7-9.2) P = 0.0008]. For both FS and LGL with arthritis, the extended haplotype HLA-A*02;B*44;Cw*0501;DRB1*0401 was significantly associated [OR 9.5 (2.6-35), P = 0.0001; OR 4.6 (1-22.4), P = 0.05, respectively]. There was no association between HLA class I or II and LGL without arthritis. All the allelic and haplotypic associations were lost on comparison with HLA-DRB1*0401+ controls. The strongest HLA association was with HLA-DRB1*0401 for FS [OR 27.9 (10.3-75.5), P = 10(-13)], and LGL with arthritis [OR 35.4 (9.6-131. 3), P = 10(-10)]. CONCLUSIONS: The major histocompatibility locus (MHC) associations with FS reported here are due to linkage disequilibrium with HLA-DRB1*0401. LGL syndrome with arthritis shows identical class II associations with FS, although there may be subtle immunogenetic differences between the two in the class I region. One of the extended haplotypes reported in a number of studies for FS and rheumatoid arthritis (summarized as HLA-A*02;Cw*0501; B*44;TNFb5;TNFa6;TNFd4;C4A*3;C4BQ*0;DRB1*0 401;DQB1*0301) is likely to be attributable to strong primary association with HLA-DRB1*0401, rather than to epistatic interaction between these loci.

CD8+, CD57+ T cells from healthy elderly subjects suppress neutrophil development in vitro: implications for the neutropenia of Felty's and large granular lymphocyte syndromes.

OBJECTIVE: To investigate the ability of CD8+,CD57+ large granular lymphocytes (LGL) from normal individuals and from Felty's syndrome (FS) or LGL syndrome patients to suppress allogeneic neutrophil precursor development. METHODS: Six FS patients, 5 LGL syndrome patients, and 13 elderly controls were studied. CD8+,CD57+ T cells were cocultured with cord blood-derived stem cells, and percentage inhibition was calculated. Recombinant chemokines and Fas-stimulating molecules were used in separate cultures to address possible mechanisms of suppression. Proliferation after stimulation with interleukin-2 (IL-2) and anti-CD3 was assessed. RESULTS: Significant (79%) suppression of colony-forming unit-granulocyte-macrophage (CFU-GM) by the CD8+,CD57+ subset was shown by 1 FS patient. None of the CD8+,CD57+ cells from LGL syndrome patients had any effect. Six of 13 controls studied showed >40% inhibition of CFU-GM, and all but 2 showed at least some suppression. The suppressive effect was not mediated by Fas/Fas ligand interactions or by the chemokines macrophage inhibitory protein 1alpha or IL-8. LGL from both patients and controls were largely CD28- and had reduced proliferative capacity. CONCLUSION: In a subset of FS patients, expansion of CD8+,CD57+ T cells in the bone marrow may be responsible for neutropenia by suppressing neutrophil precursors. This effect is also seen with normal LGL, which are likely to have an important function in neutrophil homeostasis.

Genetic polymorphism of IL-12 p40 gene in immune-mediated disease.

Understanding of the genetic basis of autoimmune diseases is currently incomplete. Cytokine gene polymorphisms warrant consideration as factors explaining variation in the human immune and inflammatory responses and as candidate susceptibility genes for related pathological states. Interleukin 12 (IL-12) is a key regulator of the polarisation of immune responses to T helper 1 or 2 categories and plays a role in autoimmune and infectious diseases. Using a bioinformatic strategy, we aligned cDNA and expressed sequence tag sequences to identify putative polymorphic regions of the IL-12 p40 gene. Position 1188 in the 3' untranslated region (UTR) was polymorphic with the frequency of the common allele around 80% in healthy UK Caucasoids. PCR genotyping of multiple Caucasoid groups and an African group showed significant population variation. In a case-control design, the polymorphism was not associated with rheumatoid arthritis, Felty's syndrome or large granular lymphocyte syndrome with arthritis or multiple sclerosis. A nonsignificant increase in the B allele frequency was observed in the rare large granular lymphocyte syndrome without arthritis (odds ratio 2.02 95% CI 0.95-4.3). This new genetic marker could be useful in anthropological studies and should be investigated in other autoimmune, allergic, inflammatory and infectious diseases.

A Fas promoter polymorphism at position -670 in the enhancer region does not confer susceptibility to Felty's and large granular lymphocyte syndromes.

OBJECTIVE: We examined whether there are associations between a polymorphism in the Fas promoter, recently found to be associated with rheumatoid arthritis (RA), and Felty's syndrome or large granular lymphocyte (LGL) leukaemia. METHODS: Thirty-five patients with Felty's were studied, along with 18 patients with LGL syndrome and arthritis, 17 patients with LGL syndrome but no arthritis, and 128 controls. The polymorphism was typed by polymerase chain reaction followed by digestion with the restriction enzyme MvaI. RESULTS: No significant difference was found in genotype or allele frequencies between the groups. CONCLUSION: This promoter polymorphism is not a significant risk factor responsible for the LGL expansions seen in Felty's and LGL syndromes. Abnormal, constitutive expression of Fas ligand may be more relevant to the aetiology of these diseases.

Interleukin-10 promoter polymorphisms in rheumatoid arthritis and Felty's syndrome.

OBJECTIVE: To examine whether promoter polymorphisms associated with variation in interleukin-10 (IL-10) production are relevant to the development of rheumatoid arthritis (RA) or Felty's syndrome (FS). METHODS: DNA was obtained from 44 FS patients, 117 RA patients and 295 controls. The promoter region between -533 and - 1120 was amplified by polymerase chain reaction, and polymorphisms detected by restriction enzyme digest or sequence-specific oligonucleotide probing. RESULTS: We found no significant difference in allele or haplotype frequencies between the groups. CONCLUSION: There is no association between FS or RA and these recently identified IL-10 promoter polymorphisms. Other genetic or environmental factors could explain the alterations in IL-10 levels seen in these conditions.

Psychopathology, executive (frontal) and general cognitive impairment in relation to duration of initially untreated versus subsequently treated psychosis in chronic schizophrenia.

BACKGROUND: It has been suggested that the expression of psychosis may reflect an active morbid process that is associated with increasingly poor outcome unless ameliorated by antipsychotic drugs. METHODS: The subjects of this study were 48 in-patients with schizophrenia, many of whom had been admitted before the introduction of antipsychotic drugs to rural Irish psychiatric hospitals in the late 1950s. Each patient was assessed for positive and negative symptoms, and for general and executive (frontal) cognitive function. RESULTS: After controlling for age and for duration and continuity of subsequent antipsychotic treatment, current severity both of negative symptoms and of general cognitive impairment was predicted strongly by increasing duration of initially untreated psychosis; duration of illness following initiation of antipsychotic medication failed to predict the severity thereof. Neither of these indices of illness duration predicted the severity of positive symptoms or of executive dyscontrol. CONCLUSIONS: Increasing duration of initially untreated psychosis was associated specifically with heightened accrual of prominent negative symptoms and general cognitive impairment. Executive dyscontrol, though also prominent in these patients, may be 'locked-in' at an earlier phase of the illness.

Executive (frontal) dysfunction and negative symptoms in schizophrenia: apparent gender differences in 'static' v. 'progressive' profiles.

BACKGROUND: While executive (frontal lobe) dysfunction appears to be a core feature of schizophrenia, its relationship to psychopathology, age and duration of illness has yet to be explored systematically between the genders. METHOD: Executive dysfunction, positive and negative symptoms were evaluated in 27 male and 21 female in-patients who were unusually well-matched on numerous demographic and clinical measures. RESULTS: Measures of executive dyscontrol and negative symptoms were highly associated in both genders. However, while both executive dyscontrol and negative symptoms increased prominently with age/ duration of illness among women, no such relationship was evident among men. CONCLUSIONS: The similarly prominent levels of current executive dyscontrol and negative symptoms in male and female patients appear to have emerged via processes that differ fundamentally between the genders; among males these deficits appear to emerge and become 'locked in' earlier in the course of illness and to show little subsequent increase, while among females these same deficits appear to be less evident early in the course but to increase in prominence thereafter.

Methionine recycling in brain: a role for folates and vitamin B-12.

The recycling of methionine via homocysteine was measured in vivo in brain. After constant intravenous infusions (5 h) of both [3H-methyl]methionine and [35S]methionine into rats, the ratios of [3H-methyl]methionine to [35S]methionine in liver, brain, and plasma were determined. Similar experiments were performed in rabbits, except that the [3H-methyl]- and [35S]methionine were injected intraventricularly. If the methyl group of methionine was removed with the formation of homocysteine and then replaced by another (unlabeled) methyl group, the specific activity of the [3H-methyl]methionine would decrease more than that of [35S]methionine; i.e., the ratio of [3H-methyl]- to [35S]methionine in the tissue would decline. The results showed that the ratios of [3H-methyl]- to [35S]methionine in liver and brain were less than the same ratio in plasma in the rats. The comparable ratios in the brain and CSF of rabbits were less than the ratio in the injectate. Since brain contains only one enzyme capable of remethylating homocysteine to methionine, the vitamin B-12-dependent methyltetrahydrofolate-homocysteine methyltransferase (EC 2.1.1.13), our results for methionine recycling via homocysteine in brain strongly support the activity of this enzyme in brain in vivo.