Society of pediatric liver transplantation: Current registry status 2011-2018

BACKGROUND

SPLIT was founded in 1995 in order to collect comprehensive prospective data on pediatric liver transplantation, including waiting list data, transplant, and early and late outcomes. Since 2011, data collection of the current registry has been refined to focus on prospective data and outcomes only after transplant to serve as a foundation for the future development of targeted clinical studies.

OBJECTIVE

To report the outcomes of the SPLIT registry from 2011 to 2018.

METHODS

This is a multicenter, cross-sectional analysis characterizing patients transplanted and enrolled in the SPLIT registry between 2011 and 2018. All patients, <18 years of age, received a first liver-only, a combined liver-kidney, or a combined liver-pancreas transplant during this study period.

RESULTS

A total of 1911 recipients from 39 participating centers in North America were registered. Indications included biliary atresia (38.5%), metabolic disease (19.1%), tumors (11.7%), and fulminant liver failure (11.5%). Greater than 50% of recipients were transplanted as either Status 1A/1B or with a MELD/PELD exception score. Incompatible transplants were performed in 4.1%. Kaplan-Meier estimates of 1-year patient and graft survival were 97.3% and 96.6%. First 30 days of surgical complications included reoperation (31.7%), hepatic artery thrombosis (6.3%), and portal vein thrombosis (3.2%). In the first 90 days, biliary tract complications were reported in 13.6%. Acute cellular rejection during first year was 34.7%. At 1 and 2 years of follow-up, 39.2% and 50.6% had normal liver tests on monotherapy (tacrolimus or sirolimus). Further surgical, survival, allograft function, and complications are detailed.

Are differences in interleukin 10 production associated with joint damage?

OBJECTIVE

Constitutive differences between individuals in cytokine production may determine the variation in the course of inflammatory arthritis.

METHODS

The association between interleukin 10 (IL-10) production and joint destruction was studied by comparing IL-10 mRNA content in synovial biopsies from seven patients with destructive joint disease and six patients with non-destructive joint disease. The IL-10 mRNA content was 0.4 +/- 0.6 arbitrary units in erosive joints compared with 2.3 +/- 1.2 arbitrary units in non-erosive joints (P: < 0.03, Mann-Whitney U:-test). As this difference suggested that IL-10 production was associated with joint destruction, we tested whether the IL-10 locus determined the extent of joint damage.

RESULTS

Innate differences in IL-10 production are locus-dependent. In line with these data, we showed that innate differences in IL-10 protein production were also present as differences in IL-10 mRNA levels. We tested if polymorphisms in the promoter of IL-10 were associated with the extent of joint damage.

DISCUSSION

In a cohort study of female rheumatoid arthritis patients followed for 12 yr, the extent of joint destruction differed significantly between patients with different IL-10 genotypes. In patients with the -1082AA genotype who were studied prospectively, the mean increase in radiographic damage score (modified Sharp score of X-rays of hands and feet) during the first 6 yr was 9 +/- 9 per yr vs 19 +/- 16 per yr for patients with the genotype -1082GG (P: < 0.02). In line with these data, cultures of endotoxin-stimulated whole blood from 158 donors showed that the presence of the allele associated with less joint destruction correlated with slightly higher IL-10 production.

CONCLUSIONS

Both the immunogenetic and the synovial biopsies suggest that a variation in IL-10 production is associated with joint destruction.

Tumour necrosis factor-alpha (TNF-alpha) enhances lymphocyte migration into rheumatoid synovial tissue transplanted into severe combined immunodeficient (SCID) mice

Adhesion mechanisms play a major role in the recruitment of peripheral blood lymphocytes (PBL) which characteristically infiltrate rheumatoid arthritis (RA) synovium and other chronically inflamed tissues. Through a sequential series of complex integrated adhesion and signalling events, 'multistep model of migration', specific subsets of PBL are recruited into inflamed tissues. In this process both leucocyte receptors and microvascular endothelial (MVE) counter-receptors play a critical role. The MVE in particular, during an inflammatory state, is the target of various inflammatory mediators that cause the up-regulation of several cell adhesion molecules (CAM). One of the most important factors known to be a powerful inducer of MVE CAM is TNF-alpha. Conversely, blocking TNF-alpha causes a down-modulation of CAM expression. To test directly the capacity of TNF-alpha to induce cell migration into RA synovium we adapted a model in which synovial grafts were implanted into SCID mice subcutaneously. Using this model we demonstrate that: (i) transplants remain viable and become vascularized and fed by mouse subdermal vessels; (ii) the mouse vasculature connects to the transplant vasculature which maintains the ability to express human CAM; (iii) intragraft injections of TNF-alpha up-regulate the expression of human CAM, following the down-regulation which occurred 4 weeks post-transplantation; and (iv) the up-regulation of graft CAM is associated with increased human PBL migration into the transplants. This study provides direct evidence in vivo of the capacity of TNF-alpha to induce cell migration. In addition, it provides the experimental background for the optimal use of this model.

CD1 expression in psoriatic and rheumatoid arthritis

OBJECTIVE

CD1 is a novel class of molecules which present non-protein antigens to T cells. The objective of this study was to evaluate the expression of CD1 in the skin and synovium of patients with psoriatic arthritis (PsA) in comparison with rheumatoid arthritis (RA) and osteoarthritis (OA).

METHODS

Paired lesional skin (SK) and synovial membrane (SM) from four PsA patients, paired SK and SM from four RA patients, SM from eight RA and eight OA patients, and normal SK from four volunteers were studied using standard immunohistochemistry.

RESULTS

In all PsA and RA skin samples CD1-positive cells were abundantly detected both in the dermis and in the epidermis. However, in the 24 SM examined CD1-positive cells were rarely found. In one patient only with RA, a few CD1a-positive cells were found in the SM. CD1b was scarcely expressed in the lining layer (LL) of five SM and in very few cells in the sublining layer (SL) of 11 SM. CD1c was rarely expressed in the LL of six SM and in very few cells in the SL of 13 SM.

CONCLUSION

The paucity of CD1 in the PsA and RA synovium suggests that different subsets of antigen-presenting cells are involved in the pathogenesis of dermatitis and synovitis, respectively.

Microscopic measurement of synovial membrane inflammation in rheumatoid arthritis: proposals for the evaluation of tissue samples by quantitative analysis

Previous studies have used various techniques for microscopic analysis of rheumatoid synovium, ranging from rapid analysis of limited areas of tissue to detailed quantification of extensive areas. The sensitivity and reproducibility of these methods have not been tested. This study sought to determine the minimum area of rheumatoid synovium needed to allow accurate microscopic analysis of synovial inflammation. Multiple synovial tissue samples were obtained from patients with rheumatoid arthritis at knee arthroplasty (n = 10), knee arthroscopy (n = 10) and by blind needle biopsy (n = 23). Lining layer thickness, sublining T-cell infiltration and vascularity were measured in all high-power fields (hpf) throughout every sample obtained from each patient. These complete measured results were compared with estimated results from limited numbers of hpf from each patient. It was observed that lining layer thickness estimated from as few as five readings from 3 samples/patient correlated significantly with the measured results obtained from as many as 85 readings/patient [Tau (T) = 0.70-0.94 for the three groups, all P < or = 0.005). Estimated measures of T-cell infiltration and vascularity derived from only 17 randomly selected hpf from 3 samples/patient (equivalent to 1 mm2) correlated significantly with the measured results obtained from up to 150 hpf/patient (T = 0.65-0.94, all P < or = 0.002). Quantitative analysis of inflammation in synovial tissue samples is both accurate and practical when restricted to an evaluation of a limited number of microscopic fields. It is proposed that lining layer thickness may be confidently quantified from five randomly selected readings from three tissue samples, and that sublining T-cell infiltration and vascularity may be quantified from 17 randomly selected hpf from the same samples.

Interleukin-1, interleukin-1 receptor antagonist and macrophage populations in rheumatoid arthritis synovial membrane

To determine whether interleukin-1 (IL-1) and interleukin-1 receptor antagonist (IL-1ra) are produced by different macrophage subsets, we applied immunoperoxidase and double-labelling immunofluorescence techniques to 10 rheumatoid arthritis (RA) and 10 osteoarthritis (OA) synovial membranes. In RA, greater numbers of early 27E10+ macrophages were found in the sublining layer while mature 25F9+ macrophages were more abundant in the lining layers. The majority of IL-1alpha+ cells were also IL-1ra+ (79 +/- 12% sublining layer, 98 +/- 2% lining layer). In OA sublining layer, a higher percentage of cells double stained for 25F9 and IL-1ra was detected compared to those double stained for 25F9 and IL-1alpha (P < 0.004). In OA, 25F9+ macrophages demonstrated a lower percentage of IL-1alpha+ in the lining and sublining layers compared to RA (P < 0.02 and P < 0.004, respectively). It may be concluded that once monocytes have migrated into the RA joint, they undergo phenotypic and functional changes from an early profile (27E10+, CD14+, low percentage of IL-1+ and IL-1ra+ cells) to a mature profile (CD14+/-, 25F9+, RM3/1+, high percentage of IL-1+ and IL-1ra+ cells).

T-lymphocyte immunophenotyping in polymyositis and dermatomyositis

The objective was to elucidate the immunological abnormalities underlying polymyositis (PM) and dermatomyositis (DM). The phenotype of peripheral blood mononuclear cell (PBMNC) subsets and cell surface expression of activation (CD25 and HLA-DR) and adhesion (LFA-1) molecules was studied in 12 patients with PM and in 10 patients with DM. PBMNC subsets and expression of T-cell activation molecules were evaluated by cytofluorography. Double immunofluorescence and indirect immunoperoxidase techniques were applied to muscle biopsies to define T-cell phenotype and LFA-1/ICAM-1 expression. In PM, the absolute number of circulating cytotoxic (CD8+CD28+) T cells was selectively reduced. T cells showed increased expression of activation molecules, CD25 and HLA-DR, and increased adhesion capacity as the absolute numbers of CD3+CD25+, CD8+HLA-DR+, CD3+LFA-1+('bright') and CD8+ CD8+LFA-1+('bright') cells were higher than in healthy donors and DM patients. In PM muscle biopsies, T cells were mainly CD3+CD8+ and LFA-1+; additionally, endothelial cells and myofibres surrounded by T cells showed positive staining for ICAM-1. In DM, there was a general lymphopenia that led to a decreased absolute number of all T-lymphocyte subsets. It is proposed that in PM, in contrast to DM, LFA-1/ICAM-1 interactions enable activated CD8+ T cells to migrate selectively into the inflamed muscle and to adhere to myofibres, leading to tissue injury.

Increased numbers of CD5+ B cells and T cell receptor (TCR) gamma delta+ T cells are associated with younger age of onset in rheumatoid arthritis (RA)

Patients presenting with RA before the age of 45 years (younger onset) are known to have more aggressive disease compared with patients presenting after the age of 65 years (older onset). Coordinated expansion of circulating CD5+ B cell and TCR gamma delta+ T cell levels has been reported in patients with RA. This study assesses the peripheral blood levels of these two cell types in RA patients with younger and older onset of disease. CD5+ B cell levels were significantly elevated in the younger onset RA group (26.6+/-4.5%) compared with the older onset RA group (14.2+/-1.2%; P<0.01). TCR gamma delta+ T cell levels were also significantly raised in the young patients (4.0+/-0.9%) compared with elderly patients (1.6+/-0.2%; P<0.01). T cell levels (CD3+) were similar in both groups (young 66.4+/-3.3%; old 74.3+/-3.4% (mean+/-s.e.m.); NS). Total B cell levels (CD19+) were also similar in these groups (7.7+/-0.7% versus 8.9+/-1.8%; NS). A significant positive correlation was observed between the CD5+ B and TCR gamma delta+ T cell types in the patients (r=0.72, P<0.05). Compared with age-matched normal controls, the younger onset patients had similar CD5+ B cell and TCR gamma delta+ T cell levels to the elderly controls (CD5+ B cells 30.2+/-3.0%; TCR gamma delta+ T cells 3.0+/-0.8%). Conversely, older onset RA patients had CD5+ B cell levels similar to the young controls (12.3+/-1.9%). Spontaneous in vitro synthesis of immunoglobulins (IgM, IgA and IgG) and rheumatoid factors (IgM and IgA isotypes) were not significantly different in both patient groups. The coordinate expansion of circulating CD5+ B cells and gamma delta+ T cells seen in patients with RA presenting before 45 years of age and not after 65 years of age may suggest a potential role for these cells in more aggressive disease states.

Cutaneous lymphocyte antigen-positive T lymphocytes preferentially migrate to the skin but not to the joint in psoriatic arthritis

OBJECTIVE

To investigate whether T cell migration into different sites of inflammation (skin and synovium) within the same individual is principally regulated by tissue-specific homing or by more general mechanisms related to inflammation.

METHODS

Expression of cutaneous lymphocyte antigen (CLA) and its ligand, E-selectin, was analyzed by immunohistochemistry and immunofluorescence using paired skin and synovial membrane (SM) samples from patients with psoriatic arthritis (PsA). To investigate disease specificity, delayed-type hypersensitivity (DTH) skin lesions, induced by tuberculin purified protein derivative, and SM from patients with rheumatoid arthritis (RA), were studied as controls. To directly examine cell migration in in vivo, the proportion of CLA+ T lymphocytes migrating into suction-induced skin blisters was assessed by flow cytometry. Using the same technique, levels of paired peripheral blood and synovial fluid (SF) T cells were also analyzed.

RESULTS

CLA+ T cells preferentially accumulated in the skin, but not in the joint, of patients with PsA. Similarly, CLA+ T lymphocytes predominated in the DTH skin lesions of RA patients, but were very rare in the SM of RA patients, and were scarcely represented in the SF of patients with several chronic inflammatory arthropathies. In addition, CLA+ T lymphocytes preferentially migrated into epidermal skin blisters. This preferential pattern of CLA+ T cell accumulation was not related to the selective expression of E-selectin, since this was similar in the skin and SM of both PsA and RA patients.

CONCLUSION

The distinct pattern of T cell infiltration into sites of inflammation within the skin and synovium is regulated by both organ-specific homing and general inflammation-related mechanisms.

Reduction of synovial inflammation after anti-CD4 monoclonal antibody treatment in early rheumatoid arthritis

OBJECTIVE

To study the effect of chimeric anti-CD4 monoclonal antibody (MAb) therapy on synovial inflammation, in order to interpret the clinical experience with anti-CD4 treatment.

METHODS

The immunohistologic features of synovial biopsy specimens before and 4 weeks after anti-CD4 MAb (cM-T412) therapy were studied in patients with rheumatoid arthritis. The patients received intravenous doses of either placebo (n = 1) or 10 mg (n = 4), 25 mg (n = 2), or 50 mg (n = 1) of cM-T412 daily for 5 consecutive days.

RESULTS

Although the patients did not experience clinical improvement, significant decreases in the number of circulating CD4+ cells, the degree of synovial inflammatory infiltration, and the mean scores for expression of adhesion molecules were found in the 7 patients 4 weeks after receiving cM-T412. The scores for infiltration with CD4+ and other inflammatory cells were particularly reduced following treatment with either 25 mg or 50 mg cM-T412. Cytokines, such as interleukin-1 beta and tumor necrosis factor alpha, could still be detected in the synovial tissue after treatment.

CONCLUSION

The decline in the numbers of inflammatory cells and adhesion molecules in synovial tissue after CD4+ cell depletion supports the view that CD4+ T cells orchestrate local cellular infiltration. The lack of clinical effect of anti-CD4 therapy might be explained by an insufficient decrease in the number of synovial CD4+ cells and by the persistence of cytokines. Determination of whether more adequate dosing would lead to a clinical improvement must await further study.

Cytokine and adhesion molecule expression in the minor salivary glands of patients with Sjögren's syndrome and chronic sialoadenitis

OBJECTIVE

To investigate the role of cytokines and cell adhesion molecules in the pathogenesis of Sjögren's syndrome (SS).

METHODS

Using an indirect immunoperoxidase technique we assessed the expression of the cytokines interleukin-1 alpha (IL-1 alpha), interleukin-1 beta (IL-1 beta), interleukin-8 (IL-8), transforming growth factor beta (TGF beta) and granulocyte macrophage colony stimulating factor (GM-CSF), of the adhesion molecules intercellular adhesion molecule-1 (ICAM-1), lymphocyte function associated antigen-1 (LFA-1), the activated molecular form of LFA-1 (NKI-L16), CD2, and LFA-3, and of a panel of cellular markers in the minor salivary glands.

RESULTS

In SS and chronic sialoadenitis (CS), the ductal epithelial cells and acini expressed all the cytokines examined. The percentage of glandular mononuclear cells which stained positive for cytokines did not differ significantly between SS and CS. NKI-L16 was detected on 33.6 (SD 10.1)% and 15.3 (4.3)% of LFA-1 cells in SS and CS, respectively (p < 0.002).

CONCLUSION

SS and CS did not differ in the pattern of cytokines examined. The characteristic cell clustering seen in the salivary glands in SS may be caused by the upregulation of NKI-L16.

Intramuscular gold decreases cytokine expression and macrophage numbers in the rheumatoid synovial membrane

OBJECTIVES

Cytokines, released from mononuclear cells (MNC) are mediators of joint destruction in rheumatoid arthritis (RA). The mechanisms of action of gold salts used in the treatment of RA are unknown. The aim of this study was to investigate cytokine expression and intensity of MNC infiltrate in the RA synovial membrane (SM) following treatment with sodium aurothiomalate (SAT).

METHODS

Sequential blind needle biopsies were obtained at entry into the study and at two and 12 weeks after the start of SAT therapy in 10 patients with active RA. SMs were stained with a panel of monoclonal antibodies to assess cytokine expression (IL-1 alpha, IL-1 beta, TNF-alpha, IL-6, and GM-CSF).

RESULTS

There was a significant decrease in IL-1 alpha, IL-1 beta, IL-6 and TNF-alpha expression 12 weeks after treatment (p < 0.004, p < 0.002, p < 0.009 and p < 0.004 respectively). This was noted in the lining layer, the perivascular aggregates and the connective tissue areas. Detailed examination of the MNC infiltrate showed a significant reduction in inflammatory monocytes (MONO) in the lining layer at two weeks (p < 0.03). A decrease in the number of CD68+ macrophages (MAC) was noted in the perivascular and connective tissue areas at 12 weeks. No significant changes were observed in the number of T and B cells and blood vessels.

CONCLUSION

The results suggest that gold may suppress RA disease activity by diminishing MONO and MAC numbers and consequently monokine production in the SM.

Synovial tissue macrophages and joint erosion in rheumatoid arthritis

OBJECTIVES

To analyse the mononuclear cell populations in synovial membrane biopsies obtained before treatment from patients with rheumatoid arthritis (RA) and to correlate the findings with the degree of joint damage occurring over one year.

METHODS

Multiple needle biopsy specimens were obtained from inflamed knee joints on entry to the study. The tissue samples were examined using immunohistochemical techniques. The degree of joint damage was estimated using the Larsen radiological index.

RESULTS

Twelve patients were studied. It was observed that there was a significant correlation between the number of synovial tissue macrophages and the degree of joint erosion over one year (r = 0.66; p = 0.04). The synovial lining layer contained large numbers of macrophages and the cellularity of the lining layer correlated significantly with the number of macrophages infiltrating the sublining areas (r = 0.65; p = 0.01). Finally, the cellularity of the lining layer correlated with the synovial fluid levels of interleukin-6 (r = 0.66; p = 0.04). The radiological course did not correlate with infiltrating T or B lymphocyte populations, but did correlate with other previously identified indicators of the clinical course, including a high index of disease activity and IgA rheumatoid factors levels.

CONCLUSION

This study suggests that synovial tissue macrophages play a critical role in the pathogenesis of joint erosion in RA.

Endogenous avidin-binding activity in epithelial cells of the ducts of human salivary glands

Avidin-biotin (AB) systems are commonly employed to investigate salivary gland sections either in immunohistochemistry or in immunofluorescence techniques. We noted non-specific staining in the ductal epithelium of minor salivary gland (SG) sections from 5 Sjögren's syndrome (SS), 5 chronic sialoadenitis (CS), and one normal parotid gland (NP) when incubated with AB peroxidase complex. Inhibition of endogenous peroxidase did not prevent the staining while saturation of supposed biotin-like molecules in the tissue with added avidin led to the loss of this non-specific staining. These results demonstrate the presence of endogenous avidin binding activity (EABA) in the epithelial cells of salivary gland ducts. We suggest that the avidin and streptavidin systems should not be used for immunohistological examination of the ductal epithelium of salivary glands.

Cytokine expression in synovial membranes of patients with rheumatoid arthritis and osteoarthritis

OBJECTIVES

To compare, by immunohistochemistry, the cellular and cytokine profile in rheumatoid arthritis (RA) and osteoarthritis (OA) synovial membranes (SMs). Synovium was obtained at knee arthroplasty from 10 patients with RA and 10 with OA.

METHODS

Synovial membranes were stained with a panel of monoclonal antibodies (MAb) to assess cytokine expression (IL-1 alpha, IL-1 beta, IL-6, GM-CSF, TNF-alpha and EGF) and the intensity of the mononuclear cellular infiltrate (MNC).

RESULTS

Significantly greater percentages of IL-1 alpha, IL-1 beta, IL-6, TNF-alpha, GM-CSF and EGF cells were detected in all areas of the rheumatoid SMs when compared with osteoarthritic SMs. Five RA but only one OA SM demonstrated focal lymphoid aggregates. Lining layer thickening was noted in RA SMs only. The intensity of the MNC and number of blood vessels were greater in the RA group.

CONCLUSION

The results suggest that the differences in cytokine production by RA and OA SMs are quantitative but that the greater thickness of the synovial lining layer and higher vascularity may be specific to RA.

Contrasting levels of in vitro cytokine production by rheumatoid synovial tissues demonstrating different patterns of mononuclear cell infiltration

Synovial membrane samples obtained at knee arthroplasty from 22 patients with rheumatoid arthritis (RA) were characterized histologically. Two groups were identified. Tissue samples from 15 patients demonstrated multiple focal lymphoid aggregates of mononuclear cells (group A). Samples from the remaining seven patients demonstrated diffuse mononuclear cell infiltration (group B). Samples of each synovial membrane (0.25 g) were cultured for cytokine production. The highest levels of IL-1 beta and IL-6 were produced by group A tissues: 19.1 +/- 19.6 ng/ml IL-1 beta (mean +/- s.d.) and 264.4 +/- 301.9 ng/ml IL-6, versus 3.8 +/- 6.6 ng/ml and 54.7 +/- 42.6 ng/ml respectively. Small quantities of IL-2 and IL-4 were measured in both groups: the levels of IL-2 in group A cultures were highest (P = 0.04). Moreover, using MoAbs, the most intense cytokine staining in the tissues was detected in group A. Similar total numbers of each cell subpopulation and similar quantities of immunoglobulin and rheumatoid factor synthesis were measured in both groups. It is suggested that the presence of multiple focal lymphoid aggregates associated with higher levels of cytokine production observed in group A represent a greater degree of immunological activation, and may represent a subgroup of patients with a greater potential for articular destruction.

A comparison of child and parent ratings of disability and pain in juvenile chronic arthritis

OBJECTIVE

To assess parent-child agreement of child disability and pain.

METHODS

Twenty children with juvenile chronic arthritis aged between 8 and 16 years and their mothers were assessed using a recently developed measure of child disability and pain.

RESULTS

Results demonstrated a high level of agreement between children and their mothers with respect to disability. However, there was no correlation between the children's and their mothers' assessment of pain.

CONCLUSION

This suggests that parents of children with chronic arthritis give accurate information regarding disability, but not regarding pain.

Reduced synovial membrane macrophage numbers, ELAM-1 expression, and lining layer hyperplasia in psoriatic arthritis as compared with rheumatoid arthritis

OBJECTIVE

To define the immunohistologic features of the synovial membrane (SM) of patients with psoriatic arthritis (PA) and to compare them with those of an age- and disease-duration-matched population of patients with rheumatoid arthritis (RA).

METHODS

Synovial membrane needle biopsy was performed on 15 PA patients with knee involvement (8 had asymmetric oligoarthritis and 7 had symmetric polyarthritis) and on 15 RA controls. Specimens were stained with monoclonal antibodies against T cells (CD3, CD8, CD4, CD45RO), B cells (CD20), macrophages (Mac387, CD14), and cells bearing class II antigens (DAKO-DR). Vascular endothelium was examined using a polyclonal antibody to Factor VIII-related antigen, and adhesion molecule expression was examined using antibodies 1.3B6, 6.5B5, and 1.4C3, which identify endothelial leukocyte adhesion molecule 1 (ELAM-1), intercellular adhesion molecule 1 (ICAM-1), and vascular cell adhesion molecule 1 (VCAM-1), respectively.

RESULTS

There was significantly less lining layer hyperplasia, fewer macrophages, and a greater number of blood vessels in PA SM than in RA SM: ELAM-1 expression was less intense in PA than in RA SM, while there was no difference in expression of ICAM-1 and VCAM-1. Numbers of B cells, T cells, and T cell subsets (predominantly CD4, CD45RO T cells) were similar in both groups of patients.

CONCLUSION

Our findings demonstrate important differences in the immunohistologic features of PA and RA SM: The PA SM is more vascular, ELAM-1 expression is less intense, and fewer macrophages invade the stroma and migrate to the lining layer than in RA SM: However, the lymphocytic infiltrate in the SM of both groups is similar.

Morphometric analysis of synovial membrane blood vessels in rheumatoid arthritis: associations with the immunohistologic features, synovial fluid cytokine levels and the clinical course

The morphologic characteristics of the endothelial cells lining postcapillary venules are cytokine dependent and critical in facilitating the infiltration of mononuclear cells into synovial membrane in rheumatoid arthritis (RA). We determined the relationships between endothelial cell (EC) tallness, mononuclear cell infiltration and synovial fluid levels of interleukin 1 beta (IL-1 beta) and interleukin 6 (IL-6) at different stages of RA. EC tallness was greatest in synovial tissues obtained by needle biopsy of the knee joints from 18 patients with active RA who had never received disease modifying drugs (Group 1) (p = 0.000001 versus controls). EC tallness in tissues obtained from 18 patients with advanced disease undergoing knee arthroplasty (Group 2) was greater than controls (p = 0.001) only when vessels located in focal lymphoid aggregates were considered. Vascular proliferation was noted in both groups. Synovial fluid IL-6 levels were greatest in Group 1. IL-1 beta levels were greatest in Group 2. The total numbers of infiltrating mononuclear cells and the clinical measures of disease activity were similar in both groups. The differences in EC characteristics at different stages of RA suggest changing pathogenic mechanisms as disease progresses. Disease modifying antirheumatic drugs may contribute to the findings observed.

Spontaneous in vitro production of rheumatoid factor during infectious exacerbations of cystic fibrosis: correlation with circulating immune complex levels

Rheumatoid factor (RF) production has been demonstrated during infections, including infectious exacerbations of cystic fibrosis (CF). The aim of this study was to evaluate the relationship of RF production to infection, and examine the mechanisms involved. Serial peripheral blood mononuclear cell (PBMC) cultures with measurement of spontaneous production of IgM RF, IgA RF, total IgM and IgA, and measurement of serum levels of immune complexes were carried out during exacerbations of CF. The percentage of B cells expressing CD5 was examined in a second cohort of acutely infected CF patients, and related to IgM RF production. IgM RF production was significantly elevated during acute infection compared with convalescence (P < 0.05), stable CF subjects (P < 0.005) and normal controls (P < 0.05). IgM RF production did not correlate with total IgM production in the majority of patients, but was closely related to circulating immune complex levels in 8/10 subjects. IgA RF production did not increase significantly during infection, and did not correlate with total IgA or IgM RF production, or with circulating immune complex levels. CD5+ B cells were not increased in the CF group, and the percentage of CD5+ B cells did not correlate with IgM RF synthesis. These observations suggest that RF production during infection is specifically induced, possibly by immune complex autoimmunization, and is not simply the result of polyclonal B cell activation. Different patterns of IgM RF and IgA RF synthesis suggest different mechanisms of induction.

Analysis of cell populations in rheumatoid arthritis synovial tissues

Knee synovium, taken from patients with rheumatoid arthritis at the time of arthroplasty, was studied immunohistologically. Focal perivascular lymphoid infiltrates of different sizes were examined in detail to evaluate changes in cell populations as the infiltrate size increased. T cells formed the largest component of mononuclear cells of all aggregates. The large grade 3 aggregates contained substantial numbers of B cells arranged around a central venule and cells bearing the CD45RA+ phenotype. In contrast, the small grade 1 aggregates contained few B cells and the T-cell population contained relatively greater numbers of CD8+ cells. Cells bearing the CD45RO+ phenotype exceeded CD45RA+ cells in grade 1 aggregates. Detailed analysis of mononuclear cell aggregates of different sizes in the rheumatoid synovium suggests that the composition of each aggregate depends on the total number of mononuclear cells it contains.

Production of angiotensin converting enzyme by rheumatoid synovial membrane

Vascular proliferation and mononuclear cell infiltration are prominent changes observed in synovium from actively inflamed joints of patients with rheumatoid arthritis. Angiotensin converting enzyme (ACE) is a halide activated peptidase produced mainly by endothelial cells and by activated monocytes. It has been proposed that levels of ACE activity in synovial fluid might reflect changes in membrane vascularity, the degree of monocyte infiltration, or the thickness of the lining layer. In this study, ACE activity in serum and synovial fluid samples from 18 patients with inflammatory arthritis was measured and compared with levels in 12 control subjects with non-inflammatory arthritis. Although serum levels were similar in the two groups, ACE activity in synovial fluid was significantly increased in the group with inflammatory arthritis compared with controls (mean (SE) 37 (5) v 19 (3)). Staining of synovial membranes from patients with rheumatoid arthritis with a monoclonal antibody to ACE localised ACE to the endothelium and to mononuclear cells of macrophage origin. ACE activity was then measured in supernatants of synovial membrane from patients with rheumatoid arthritis after one and seven days of culture. A significant increase in ACE activity was observed after seven days of culture (mean (SE) day 1, 17 (5) v day 7, 25 (3)). Levels of ACE activity, however, did not correlate with the lining layer thickness, with the number of macrophages per square millimetre, nor with the number of blood vessels per square millimetre of synovial tissue. No correlation was observed either between levels of ACE in the supernatant of synovial membrane and levels of interleukin 1 or interleukin 6. In conclusion, ACE is produced by the synovial membrane of patients with rheumatoid arthritis and is localised to monocytes and endothelial cells. Levels of activity do not directly reflect membrane vascularity, monocyte or macrophage number, or the thickness of the lining layer.

Morphometric analysis of blood vessels in synovial membranes obtained from clinically affected and unaffected knee joints of patients with rheumatoid arthritis

Synovial tissues from inflamed and noninflamed knee joints of 13 patients with untreated rheumatoid arthritis were examined for vascular proliferation and morphological alteration of endothelial cells. Perivascular mononuclear cell infiltration and increased thickness of the synovial lining layer were noted in tissues from inflamed and noninflamed joints of patients with rheumatoid arthritis; vascular proliferation and morphological alteration of endothelial cells to resemble high endothelial venules were seen only in tissues from inflamed joints of patients with rheumatoid arthritis. These observations suggest that the migration of mononuclear cells from the peripheral blood to the perivascular areas and lining layer occurs before vascular proliferation and morphological alteration of endothelial cells.

Colonic motility and transit in health and ulcerative colitis

Preprandial and postprandial colonic motility and transit (scintigraphy), with respect to the splenic flexure, were studied in 10 patients with ulcerative colitis and in 9 healthy subjects. The healthy subjects had a postprandial increase in intraluminal pressure that was significantly (P less than 0.03) greater in the descending colon than in other regions of the colon. In ulcerative colitis, the pressure was decreased in all regions compared with healthy subjects, with no significant pressure gradient among different regions. In normal subjects, transit was quiescent during fasting; eating stimulated both antegrade and retrograde transit. In ulcerative colitis, transit was variable before as well as after the meal. Both healthy subjects and patients with ulcerative colitis had more rapid emptying from the splenic flexure into the sigmoid than into the transverse colon. More frequent, low-amplitude, postprandial propagating contractions occurred in ulcerative colitis (P less than 0.05) than in healthy subjects. Propagating contractions were always antegrade and caused a rapid movement of the tracer into the sigmoid. In conclusion, ulcerative colitis is characterized by (a) decreased contractility, (b) increased low-amplitude propagating contractions, and (c) variable transit. These disturbances may accentuate the diarrhea in ulcerative colitis.

Experience with a juvenile rheumatology clinic

A dedicated monthly clinic for children with rheumatic diseases was established in order to cater for the increasing number of referrals to a rheumatology department for assessment and management. The clinic was staffed by a consultant rheumatologist, registrar, nurse, physiotherapist and occupational therapist. Seventy-four children, 44 girls and 30 boys, were assessed during the first 32 months. The mean age at referral was 10 years (range 2-15). Thirty-three had juvenile chronic arthritis. Other disease categories included dermatomyositis, systemic lupus erythematosus and reactive arthritis. Twenty-eight children were referred by general practitioners and 26 by paediatricians. Hospital admission was required by 24. These observations suggest the need in Ireland for a coordinated service for children with rheumatic diseases.