Intestinal mucosal permeability and rheumatological diseases

Cause analysis of conversion to biologics in spondyloarthritis patients with poor response to conventional treatment

OBJECTIVE

We sought to investigate the reasons why spondyloarthritis (SpA) patients failed to respond to non-steroidal anti-inflammatory drugs (NSAIDs) and conventional synthetic disease-modifying antirheumatic drugs (cDMARDs) and the influences of different initial cDMARDs on the likelihood of a switch to biologics.

METHODS

SpA patients were divided into a conventional drug maintenance group and a biologics conversion group to determine the causes of conversion to biologics. Then, we divided all patients into three groups according to different initial cDMARDs, NSAID monotherapy, NSAID + (sulfasalazine or thalidomide) double combination, and NSAID + sulfasalazine + thalidomide triple combination therapy groups, to clarify the influence of initial treatment on later conversion to biologics.

RESULTS

This study includes 202 patients, including 97 patients in the conventional drug maintenance group and 105 patients in the biologics conversion group. The mean age of the conventional drug maintenance group was higher than that of the biologics conversion group (40.8 ± 14.3 vs. 33.8 ± 12.3 years, P < 0.05). Uveitis (OR 5.356, P < 0.05) is positively correlated with conversion to biological therapy, while age (OR 0.940, P < 0.05) is negatively correlated. The proportion of NSAID monotherapy, double combination, and triple combination groups converted to biological agents was 80%, 51.1%, and 23.2%, respectively (P < 0.05).

CONCLUSION

Age and uveitis are related to conversion to biologics therapy. The early combination of sulfasalazine and thalidomide with NSAIDs may lower the probability of conversion to biologics therapy in the later stage and offer a new option for patients with limited use of biologics in SpA patients. Key Points • Patients' move to biologics may be caused mostly by inadequate disease control by conventional oral medications. • Regardless of axial vs. peripheral joint involvement, combination drug therapy was superior to single drug therapy in controlling SpA and decreasing the probability of conversion to a biological agent. • For SpA patients who are not candidates for biologics due to contraindications or other reasons, early combination application of NSAIDs, sulfasalazine, and thalidomide may be a new choice.

Gut Microbiome of Healthy and Arthritic Dogs

Several studies have underlined the interplay among host-microbiome and pathophysiological conditions of animals. Research has also focused specifically on whether and how changes in the gut microbiome have provoked the occurrence of pathological phenomena affecting cartilage and joints in humans and in laboratory animals. Here, we tried to evaluate the relationship between the gut microbiome and the hip and elbow arthritis in owned dogs. The study included 14 dogs suffering from chronic arthritis (AD) and 13 healthy dogs (HD). After the first visit and during the period of the study, the dogs, under the supervision of the owner, were fed a semi-moist complete diet supplemented with omega 3 fatty acids. Feces and blood samples were collected in the clinic at the first visit (T0) and after days (T45). The plasma C-reactive protein (CRP) was higher, and the serum vitamin B12 and folate concentrations were lower (p < 0.05) in the AD group in comparison to the HD group. Data of the fecal microbiome showed that the relative abundances of the genus Megamonas were higher in AD (p < 0.001), while the relative abundance of the families Paraprevotellaceae, Porphyromonadaceae, and Mogibacteriaceae was significantly lower in comparison to HD. The results of the study identified several bacterial groups that differed significantly in the fecal microbiome between healthy and diseased dogs. If the observed differences in fecal bacterial composition predispose dogs to hip and elbow arthritis or if these differences reflect a correlation with these conditions deserves further investigation.

Gut microbiota and obesity-associated osteoarthritis

Obesity is a well-known primary risk factor for osteoarthritis (OA). In recent decades, the biomechanics-based theoretical paradigm for the pathogenesis of obesity-associated OA has been gradually but fundamentally modified. This modification is a result of accumulating evidence that biological factors also contribute to the etiology of the disease. The gut microbiota is a complicated ecosystem that profoundly influences the health of the host and can be modulated by the combined effects of environmental stimuli and genetic factors. Recently, enteric dysbacteriosis has been identified as a causal factor in the initiation and propagation of obesity-associated OA in animal models. Gut microbes and their components, microbe-associated lipid metabolites, and OA interact at both systemic and local levels through mechanisms that involve interplay with the innate immune system. However, the demonstration of causality in humans will require further studies. Nonetheless, probiotics, prebiotics, dietary habits and exercise, which aid the restoration of a healthy microbial community, are potential therapeutic approaches in the treatment of obesity-associated OA.

Intake of high-fructose corn syrup sweetened soft drinks, fruit drinks and apple juice is associated with prevalent arthritis in US adults, aged 20-30 years

OBJECTIVE

There is a link between joint and gut inflammation of unknown etiology in arthritis. Existing research indicates that regular consumption of high-fructose corn syrup sweetened (HFCS) soft drinks, but not diet soft drinks, may be associated with increased risk of seropositive rheumatoid arthritis (RA) in women, independent of other dietary and lifestyle factors. One unexplored hypothesis for this association is that fructose malabsorption, due to regular consumption of excess free fructose (EFF) and HFCS, contributes to fructose reactivity in the gastrointestinal tract and intestinal in situ formation of enFruAGEs, which once absorbed, travel beyond the intestinal boundaries to other tissues and promote inflammation. In separate studies, the accumulation of advanced glycation end-products has been associated with joint inflammation in RA. Objective of this study was to assess the association between EFF beverages intake and non-age, non-wear and tear-associated arthritis in US young adults.

METHODS

In this cross sectional study of 1209 adults aged 20-30y, (Nutrition and Health Examination Surveys 2003-2006) exposure variables were high EFF beverages, including HFCS sweetened soft drinks, and any combination of HFCS sweetened soft drinks, fruit drinks (FD) and apple juice, referred to as tEFF. Analyses of diet soda and diet FD were included for comparison. The outcome was self-reported arthritis. Rao Scott Ҳ(2) was used for prevalence differences and logistic regression for associations, adjusted for confounders.

RESULTS

Young adults consuming any combination of high EFF beverages (tEFF) ⩾5 times/week (but not diet soda) were three times as likely to have arthritis as non/low consumers (odds ratios=3.01; p⩽0.021; 95% confidence intervals=1.20-7.59), independent of all covariates, including physical activity, other dietary factors, blood glucose and smoking.

CONCLUSION

EFF beverage intake is significantly associated with arthritis in US adults aged 20-30 years, possibly due to the intestinal in situ formation of enFruAGEs.

Overexpression of miR-595 and miR-1246 in the sera of patients with active forms of inflammatory bowel disease

BACKGROUND

MicroRNAs (miRNAs) are dysregulated in the inflammatory bowel diseases, Crohn's disease (CD) and ulcerative colitis (UC), which arise due to dysfunctional host-microbe interactions and impairment of the barrier function of the intestine. Here, we sought to determine whether circulating miRNAs are biomarkers of active colonic CD and UC and can provide insights into disease pathogenesis. Comparison was made with serum miRNAs in patients with rheumatoid arthritis (RA).

METHODS

Total serum RNA from patients with colonic CD, UC, and RA, and normal healthy adults was screened for disease-associated miRNAs by microarray analysis, with subsequent validation by quantitative reverse-transcription polymerase chain reaction. MiRNA targets were identified by luciferase reporter assays.

RESULTS

MiR-595 and miR-1246 were significantly upregulated in the sera of active colonic CD, UC, and RA patients, compared with healthy subjects; and in active colonic CD and UC compared with inactive disease. Luciferase reporter assays indicated that miR-595 inhibits the expression of neural cell adhesion molecule-1 and fibroblast growth factor receptor 2.

CONCLUSIONS

Serum miR-595 and miR-1246 are biomarkers of active CD, UC, and RA. These findings gain significance from reports that miR-595 impairs epithelial tight junctions, whereas miR-1246 indirectly activates the proinflammatory nuclear factor of activated T cells. miR-595 targets the cell adhesion molecule neural cell adhesion molecule-1, and fibroblast growth factor receptor 2, which plays a key role in the differentiation, protection, and repair of colonic epithelium, and maintenance of tight junctions. miR-595 and miR-1246 warrant testing as potential targets for therapeutic intervention in the treatment of inflammatory bowel disease.

Human β-defensin 3 peptide is increased and redistributed in Crohn's ileitis

BACKGROUND

Antimicrobial peptides (AMPs) maintain a sterile environment in intestinal crypts, limiting microbial colonization and invasion. Decreased AMP expression is proposed to increase the risk for inflammatory bowel disease. Expression and function of inducible AMPs, human β-defensin 2 and 3 (hBD-2 and hBD-3), remain poorly characterized in healthy and chronically inflamed intestine.

METHODS

Peptide concentrations of hBD-2 and hBD-3 in serum and intestinal biopsies of subjects with ulcerative colitis and Crohn's disease (CD), and those of healthy subjects were measured by ELISA. Messenger RNA of hBD-2 and hBD-3 was quantified by quantitative PCR in biopsies from the terminal ileum (TI) of patients with CD and healthy controls. Peptide localization of hBD-3 in the TI was visualized by confocal microscopy.

RESULTS

Immunoreactive hBD-3 peptide is present in the TI and colon in healthy subjects. In the TI of patients with CD, hBD-3, but not hBD-2 peptide, is increased 4-fold, whereas hBD-2 peptide is elevated in the serum. Messenger RNA of hBD-3 in the CD TI remains unchanged and does not correlate with hBD-3 peptide expression. However, hBD-3 is localized to Paneth cell granules and the apical surface of the healthy columnar epithelium. In CD, hBD-3 peptide location switches to the basolateral surface of the columnar epithelium and is diffusely distributed within the lamina propria.

CONCLUSION

The peptide hBD-3 throughout the healthy gastrointestinal tract suggests a role in maintaining balance between host defenses and commensal microbiota. Increased and relocalized secretion of hBD-3 toward the lamina propria in the CD TI indicates possible local immunomodulation during chronic inflammation, whereas increased serum hBD-2 in CD implicates its systemic antimicrobial and immunomodulatory role.

Self-reported food intolerance and mucosal reactivity after rectal food protein challenge in patients with rheumatoid arthritis

OBJECTIVES

A dietary link to rheumatoid arthritis (RA) has been suspected and an influence on arthritic symptoms by different diets has been reported. Our primary aim was to record the self-experienced adverse food reactions in patients with RA. A secondary aim was to relate self-experienced adverse reactions to dairy produce and wheat to the local mucosal reactivity observed after rectal challenge with cow's milk protein (CM) and wheat gluten.

METHODS

A questionnaire about self-experienced adverse reaction to food was sent to 347 RA patients. Rectal challenge with CM and gluten was performed in 27 of these patients and in healthy controls (n = 18). After a 15-h challenge the mucosal production of nitric oxide (NO) and the mucosal release of myeloperoxidase (MPO) and eosinophil cationic protein (ECP) were measured by using the mucosal patch technique.

RESULTS

Twenty-seven per cent of the RA patients reported food intolerance (FI) to various foods, and in particular to CM, meat, and wheat gluten. Strong mucosal reactivity to CM was observed in 11% of the patients. Moderately increased mucosal reactivity to CM and gluten was found in 22% and 33%, respectively, of the patients. No relationship was found between self-experienced adverse reactions to CM or gluten and mucosal reactivity to these proteins.

CONCLUSIONS

Perceived FI is reported frequently by RA patients, with a prevalence similar to that reported previously in the general population. Mucosal reactivity to CM and gluten is seen in a minor fraction of RA patients and is not related to the frequently perceived intolerance to these proteins.

Prohibitin inhibits tumor necrosis factor alpha-induced nuclear factor-kappa B nuclear translocation via the novel mechanism of decreasing importin alpha3 expression

Expression of prohibitin 1 (PHB), a multifunctional protein in the cell, is decreased during inflammatory bowel disease (IBD). Little is known regarding the regulation and role of PHB during intestinal inflammation. We examined the effect of tumor necrosis factor alpha (TNF-alpha), a cytokine that plays a central role in the pathogenesis of IBD, on PHB expression and the effect of sustained PHB expression on TNF-alpha activation of nuclear factor-kappa B (NF-kappaB) and epithelial barrier dysfunction, two hallmarks of intestinal inflammation. We show that TNF-alpha decreased PHB protein and mRNA abundance in intestinal epithelial cells in vitro and in colon mucosa in vivo. Sustained expression of prohibitin in intestinal epithelial cells in vitro and in vivo (prohibitin transgenic mice, PHB TG) resulted in a marked decrease in TNF-alpha-induced nuclear translocation of the NF-kappaB protein p65, NF-kappaB/DNA binding, and NF-kappaB-mediated transcriptional activation despite robust IkappaB-alpha phosphorylation and degradation and increased cytosolic p65. Cells overexpressing PHB were protected from TNF-alpha-induced increased epithelial permeability. Expression of importin alpha3, a protein involved in p50/p65 nuclear import, was decreased in cells overexpressing PHB and in colon mucosa of PHB TG mice. Restoration of importin alpha3 levels sustained NF-kappaB activation by TNF-alpha during PHB transfection. These results suggest that PHB inhibits NF-kappaB nuclear translocation via a novel mechanism involving alteration of importin alpha3 levels. TNF-alpha decreases PHB expression in intestinal epithelial cells and restoration of PHB expression in these cells can protect against the deleterious effects of TNF-alpha and NF-kappaB on barrier function.

Small-bowel permeability in collagenous colitis

OBJECTIVE

Collagenous colitis (CC) is a chronic inflammatory bowel disease that affects the colon. However, some patients with CC present with accompanying pathologic small-bowel manifestations such as coeliac disease, defects in bile acid absorption and histopathologic changes in small-intestinal biopsies, indicating that CC is a pan-intestinal disease. In small-intestinal disease, the intestinal barrier function may be impaired, and the permeability of the small intestine altered. The purpose of this research was to study small-bowel function in patients with CC as expressed by intestinal permeability.

MATERIAL AND METHODS

Ten patients with CC and chronic diarrhoea participated in the study. Coeliac disease was excluded by small-bowel biopsy and/or serology. Intestinal permeability was assessed as urinary excretion (ratios) 2, 4 and 6 h after ingestion of 14C-labelled mannitol (14C-mannitol) and 99mTc-labelled diethylenetriamine-pentaacetic acid (99mTc-DTPA). Data were compared with the results from healthy controls.

RESULTS

No difference was found between groups in urinary excretion of 14C-mannitol and 99mTc-DTPA after 2, 4 or 6 h, respectively. Likewise, no significant differences in the 99mTc-DTPA/14C-mannitol ratios between patients and controls were detected after 2 h: 0.030 (0.008-0.130) versus 0.020 (0.007-0.030), p = 0.19, after 4 h: 0.040 (0.009-0.180) versus 0.020 (0.008-0.040), p = 0.14 or after 6 h: 0.040 (0.012-0.180) versus 0.020 (0.010-0.040), p = 0.17.

CONCLUSIONS

No alterations in intestinal permeability in patients with CC could be demonstrated. Impairment of the integrity of the mucosa of the small bowel and the presence of a general dysfunction of the small intestine in patients with CC seem unlikely.

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.

Evaluation of the lactulose/mannitol and 51Cr-ethylenediaminetetraacetic acid/14C-mannitol methods for intestinal permeability

BACKGROUND

We earlier compared the lactulose/mannitol and 51Cr-ethylenediaminetetraacetic acid (EDTA)/14C-mannitol methods for intestinal permeability We have now investigated an increased number of control subjects, with special regard to the influence of urinary volume, sex, age, and smoking on marker excretion, and patients with intestinal disorders, with special regard to correlations between markers.

METHODS

The 0- to 6-h urinary excretion of orally administered markers was measured in 65 control subjects and in 70 patients.

RESULTS

In the control group excretion of mannitol and 14C-mannitol (small-pore permeability markers) was strongly correlated to urinary volume, whereas such correlation was weak for lactulose and absent for 51Cr-EDTA (large-pore permeability markers). No sex difference in marker excretion was found, but correlation to urinary volume was more pronounced in males. There was a slightly decreasing excretion of markers with increasing age, reaching significance for 51Cr-EDTA and 14C-mannitol; their excretion ratio was unaffected. Smoking did not significantly affect marker excretion. In the patient group the excretion of large-pore markers tended to be higher and that of small-pore markers to be lower than in the control group; correlation between the large-pore markers, between the small-pore markers, and between the large-pore/small-pore marker ratios was higher than in the control group.

CONCLUSIONS

Correction for urinary volume substantially reduces variability in small-pore marker excretion. Excretion of both types of markers tends to decrease with age, the large-pore/small-pore marker ratio remaining unchanged. Smoking does not affect small-intestinal permeability. 14C-mannitol is preferred to chemically determined mannitol owing to lower test variability.

Intestinal inflammation and barrier function in HLA-B27/beta 2-microglobulin transgenic rats

BACKGROUND

Since intestinal inflammation is correlated with impaired barrier functions, transgenic HLA-B27/human beta 2-microglobulin rats that spontaneously develop intestinal inflammation were used to investigate whether onset of inflammation or impaired barrier function was the initial event.

METHODS

During the age period of 9-14 weeks, transgenic and non-transgenic (control) rats were gavaged weekly with the marker molecules, 51Cr-ethylenediaminetetraacetic acid, 1-deamino-8-D-arginine vasopressin, and albumin, which were quantified in blood or urine.

RESULTS

At 12 weeks of age the first signs of inflammation appeared with decreased body weight gain, decreased urine production, and onset of diarrhea. By 14-15 weeks of age all transgenic rats had developed intestinal inflammation, as confirmed by histology and increased myeloperoxidase content, whereas no inflammation was observed in controls. Intestinal passage of the markers did, however, not differ between transgenic and control rats over the studied period.

CONCLUSIONS

The results suggest that intestinal inflammation precedes altered intestinal barrier function in this inflammation model.

Physiochemical and physiological mechanisms for the effects of food on drug absorption: the role of lipids and pH

Drugs are absorbed after oral administration as a consequence of a complex array of interactions between the drug, its formulation, and the gastrointestinal (GI) tract. The presence of food within the GI tract impacts significantly on transit profiles, pH, and its solubilization capacity. Consequently, food would be expected to affect the absorption of co-administered drugs when their physicochemical properties are sensitive to these changes. The physicochemical basis by which ingested food/lipids induce changes in the GI tract and influence drug absorption are reviewed. The process of lipid digestion is briefly reviewed and considered in the context of the absorption of poorly water-soluble drugs. The effect of food on GI pH is reviewed in terms of location (stomach, upper and lower small intestine) and the temporal relationship between pH and drug absorption. Case studies are presented in which postprandial changes in bioavailability are rationalized in terms of the sensitivity of the physicochemical properties of the administered drug to the altered GI environment.

Which is the active moiety of sulfasalazine in ankylosing spondylitis? A randomized, controlled study

OBJECTIVE

To compare the efficacy of sulfasalazine (SSZ) with its two moieties, 5-aminosalicylic acid (ASA) and sulfapyridine (SP), in patients with active ankylosing spondylitis (AS).

METHODS

A 26-week randomized, observer-blinded, 2-center, controlled study of treatment with either SSZ, ASA, or SP was conducted in 90 patients with active AS. Patients were evaluated at baseline and at monthly intervals, using several clinical and laboratory measures of disease activity. A global assessment of treatment efficacy was made by both patients and observers at the end of the study period.

RESULTS

There were no significant changes in any of the parameters of disease activity in the ASA treatment group. Levels of serum IgG, IgA, and IgM fell significantly during treatment with SP, but none of the other changes reached statistical significance. Plasma viscosity and IgG and IgA levels fell significantly during treatment with SSZ, as did nocturnal spinal pain and overall spinal pain. Patients and observers reported a favorable outcome after treatment with SSZ or SP significantly more often than with ASA treatment.

CONCLUSION

SP appears to be the active moiety in AS, although there was a trend suggesting a better outcome in the SSZ group compared with the SP group, perhaps suggesting the importance of a common sulfonamide structure for efficacy.

Spondylarthropathies: from gut to target organs

Recent studies strongly support the concept that gut and joint inflammation are closely related. Progress also has been made in identifying individual mechanisms that contribute to the pathogenesis of joint disease in IBD and in undifferentiated SpAs. However, the interrelationship of these mechanisms that result in chronic disease manifestations at a site distant from the initiating event remain to be elucidated. The local absence of homing molecule receptors in the gut wall combined with an expression of these receptors in target organs can be responsible for the transformation of the synovial membrane and/or the enthesis into an aberrant tertiary lymphoid organ of the gut.

Evidence of a local intestinal immunomodulatory effect of sulfasalazine in rheumatoid arthritis

OBJECTIVE

To analyze whether the intestinal mucosa in rheumatoid arthritis (RA) is immunologically abnormal and whether sulfasalazine (SSZ) possesses any local intestinal immunoregulatory effect.

METHODS

Lymphocyte subpopulations and HLA-DR expression were evaluated in biopsy specimens from the duodenal-jejunal mucosa and in peripheral blood samples obtained from 17 patients with RA, both before and after 16 weeks of SSZ treatment. The same mucosal assays were also performed in 7 controls.

RESULTS

The mucosa of the small intestine in RA patients showed no differences in morphology, HLA-DR expression, or the amounts and distribution of CD3+, CD4+, CD8+, and gamma/delta + lymphocytes compared with the control group. However, there was a reduction in mucosal CD3+ and gamma/delta + lymphocyte numbers after SSZ therapy, which did not correspond to a change in peripheral blood CD3+ lymphocyte number. SSZ treatment also tended to diminish the peripheral blood CD4+:CD8+ cell ratio (P = 0.05).

CONCLUSION

No signs of inflammation or immunologic abnormalities were seen in RA duodenal-jejunal mucosa. In this part of the intestine, however, SSZ exerted immunoregulatory effects that were not encountered in the peripheral blood.

The gut as an inductive site for synovial and extra-articular immune responses in rheumatoid arthritis

OBJECTIVES

To analyse the immunological interactions between the gut lymphoid tissue, synovium, and peripheral blood compartments in patients with rheumatoid arthritis (RA) and ankylosing spondylitis (AS).

METHODS

Patients with RA and AS and healthy controls were orally or parenterally immunised with an influenza virus vaccine. Antigen-specific antibody responses were measured at the single cell level by ELISPOT assay using lymphocytes isolated from peripheral blood and from enzymatically dispersed synovial tissues.

RESULTS

Both oral and parenteral immunisations induced antigen-specific antibody-secreting cells in the synovial tissue of patients with RA. Parenterally immunised patients with RA showed significantly decreased antigen-specific antibody responses in peripheral blood compared with patients with AS and with healthy controls. In contrast, oral vaccination evoked comparable peripheral blood antibody responses in all three study groups.

CONCLUSIONS

Despite a decreased immune responsiveness in the systemic compartment, the functional status of the gut-associated lymphoid tissue in patients with RA is intact. In addition, there is evidence that the lymphocytes in the inflamed joints are accessible for signals both from the systemic and mucosal compartments. The findings of immunological 'cross-talk' are relevant to future vaccination and tolerization procedures in patients with RA.

A new diffusion chamber system for the determination of drug permeability coefficients across the human intestinal epithelium that are independent of the unstirred water layer

A new method for determining permeability coefficients, that are independent of the unstirred water layer (UWL), has been developed. The method was used to determine the cellular permeability coefficient of the rapidly absorbed drug testosterone in monolayers of the human intestinal epithelial cell line, Caco-2. Using a new diffusion cell with an effective stirring system based on a gas lift, the cellular permeability coefficient for testosterone was (1.98 +/- 0.13).10(-4) cm/s which is 3.5-times higher than the permeability coefficient obtained in the unstirred system. The thickness of the UWL obtained with the well stirred diffusion cell was 52 +/- 4 microns. This value is much lower than those previously reported in various well stirred in vitro models. The calculated cellular permeability of testosterone was 13-23-times lower than that for an UWL of the same thickness as the epithelial cell (17-30 microns). We conclude that the permeability of the epithelial monolayer must be included in calculations of the thickness of the UWL.