Influence of low socioeconomic status on mortality in granulomatosis with polyangiitis.

Objectives: To evaluate the influence of low socioeconomic status (SES) on mortality among patients with granulomatosis with polyangiitis (GPA).Methods: Using nationwide registers, we established a cohort of 827 patients diagnosed with GPA in the public hospital system of Denmark. For each patient, information regarding educational level, civil status, employment status, and comorbidities at time of GPA diagnosis was collected. We used Cox regression analyses to calculate hazard ratios (HRs) adjusted for age, gender, calendar period of GPA diagnosis, and Charlson Comorbidity Index score for preceding illnesses as a measure of relative risk of death. We assessed the risk of death associated with three measures of low SES: basic schooling only, civil status as single, and being unemployed or recipient of disability pension.Results: The median age of patients at GPA diagnosis was 61 (interquartile range 51-69) years, and 508 were 18-64 years old. During a total of 4337 person-years, 237 patients died. Among patients aged 18-64 years at GPA diagnosis, all three measures of low SES were identified as risk factors for death [basic schooling only: HR = 2.04, 95% confidence interval (CI) 1.30-3.19; civil status as single: HR = 1.95, 95% CI 1.24-3.05; being unemployed or recipient of disability pension: HR = 2.96, 95% CI 1.72-5.08]. The association between low SES and mortality was less pronounced among patients aged ≥ 65 years.Conclusions: Our observations indicate that low SES is associated with increased mortality in GPA, especially among patients of working age.

Clinical and biochemical presentation of sarcoidosis with high and normal serum angiotensin-converting enzyme.

OBJECTIVES: The presentation of sarcoidosis can involve symptoms from all organs and the diagnosis is therefore often difficult. A raised serum level of serum angiotensin-converting enzyme (sACE) can be detected in 41-58% of patients. However, whether the sACE level per se reflects the severity of the sarcoid inflammation at the onset of the disease is not well described. The purpose of this study was to investigate the clinical and laboratory significance of high versus normal sACE levels in sarcoidosis. METHOD: Journal data were retrospectively extracted from 101 patients from our clinic. Clinical and biochemical data were compared between patients with high sACE levels (> 115 U/L) on at least one occasion and normal sACE levels (< 115 U/L). RESULTS: In total, 48% (n = 48) of the patients had high ACE and 52% (n = 53) had normal ACE. The most common extrapulmonary manifestation for both groups was arthritis, followed by skin and eye involvement, but none of these differed between the two groups. Serum ionized calcium was significantly higher in the high sACE group, with a correlation coefficient of 0.112 (p = 0.460). CONCLUSION: Our study demonstrates that serum ionized calcium is significantly higher in the high sACE group but there was no statistical correlation to sACE. No other clinical or biochemical differences were observed.

Long-term risk and outcome of infection-related hospitalization in granulomatosis with polyangiitis: a nationwide population-based cohort study.

OBJECTIVE: To assess the long-term risk and outcome of infection-related hospitalization (IH) among patients with granulomatosis with polyangiitis (GPA). METHOD: We used administrative databases to establish a GPA cohort (n = 398), construct a comparison cohort of population controls (n = 3980), and collect clinical data. Cox regression analyses were used to determine hazard ratios (HRs) as a measure of relative risk. Follow-up began at date of GPA diagnosis and continued for up to 10 years. RESULTS: GPA patients had a markedly increased long-term risk of IH compared to controls [HR (95% confidence interval) year 1: 9.5 (7.0-12.8); years 2-5: 3.2 (2.4-4.3); years 6-10: 2.6 (1.8-3.9)]. Increased long-term risks were found for hospital-treated pneumonia, urinary tract infection, sepsis, and skin infection. We did not observe a lower risk of IH for people diagnosed with GPA during 2005-2014 than for those diagnosed during 1995-2004. Mortality at 3 and 6 months after IH did not differ significantly between patients diagnosed with vasculitis during 2005-2014 and those diagnosed during 1995-2004. Charlson Comorbidity Index score ≥1 was identified as a predictor of pneumonia and urinary tract infection in the GPA cohort, but not of sepsis or skin infection. CONCLUSION: Patients with GPA have a high risk of IH, even after prolonged follow-up. The long-term risk of IH and mortality after IH did not decline across recent calendar periods among Danish GPA patients. These observations underscore the need for clinical strategies to reduce the burden of infectious complications in GPA.

Incidence of granulomatosis with polyangiitis (Wegener's) in Greenland and the Faroe Islands: epidemiology of an ANCA-associated vasculitic syndrome in two ethnically distinct populations in the North Atlantic area.

OBJECTIVES: Previous studies suggest that the incidence of granulomatosis with polyangiitis (Wegener's; GPA) increases along a south-north gradient in the Northern Hemisphere with an incidence of 8.0/million/year reported for the population of Northern Norway. In the present study, we assessed the incidence of GPA in the predominantly Inuit population of Greenland and in the Caucasian population of the Faroe Islands. METHODS: Greenlandic and Faroese patients affected by severe rheumatic diseases are routinely referred to the National University Hospital in Denmark for treatment. By means of the Danish National Hospital register, we identified all Greenlandic and Faroese patients treated at the hospital under a diagnosis of GPA during 1992-2011. For each patient, the GPA diagnosis was validated by medical files review. RESULTS: One patient born and living in Greenland and 6 from the Faroe Islands were identified. The incidence of GPA was 1.0/million/year (95% CI 0.02-5.6) in Greenland and 6.4/million/year (95% 2.4-14.0) in the Faroe Islands. During the period of study, no cases of GPA occurred among Greenlanders aged 0-44 years, while an incidence of 4.1/million/year (95% CI: 0.1-22.9) was calculated for those aged ≥45 years. In the Faroese population, incidences of 1.7/million/year (95% CI 0.4-9.4) and 14.8/million/year (95% CI 4.8-34.6) were calculated for the age-groups 0-44 and ≥45 years, respectively. CONCLUSIONS: The occurrence of GPA is lower among Inuit in Greenland than among Caucasians living in the Faroe Islands. This observation demonstrates that the risk of GPA varies across ethnic groups populating the northernmost regions of the world.

Deoxyspergualin in relapsing and refractory Wegener's granulomatosis.

OBJECTIVES: Conventional therapy of Wegener's granulomatosis with cyclophosphamide and corticosteroids is limited by incomplete remissions and a high relapse rate. The efficacy and safety of an alternative immunosuppressive drug, deoxyspergualin, was evaluated in patients with relapsing or refractory disease. METHODS: A prospective, international, multicentre, single-limb, open-label study. Entry required active Wegener's granulomatosis with a Birmingham vasculitis activity score (BVAS) > or =4 and previous therapy with cyclophosphamide or methotrexate. Immunosuppressive drugs were withdrawn at entry and prednisolone doses adjusted according to clinical status. Deoxyspergualin, 0.5 mg/kg per day, was self-administered by subcutaneous injection in six cycles of 21 days with a 7-day washout between cycles. Cycles were stopped early for white blood count less than 4000 cells/mm(3). The primary endpoint was complete remission (BVAS 0 for at least 2 months) or partial remission (BVAS <50% of entry score). After the sixth cycle azathioprine was commenced and follow-up continued for 6 months. RESULTS: 42/44 patients (95%) achieved at least partial remission and 20/44 (45%) achieved complete remission. BVAS fell from 12 (4-25), median (range) at baseline to 2 (0-14) at the end of the study (p<0.001). Prednisolone doses were reduced from 20 to 8 mg/day (p<0.001). Relapses occurred in 18 (43%) patients after a median of 170 (44-316) days after achieving remission. Severe or life-threatening (> or = grade 3) treatment-related adverse events occurred in 24 (53%) patients mostly due to leucopaenias. CONCLUSIONS: Deoxyspergualin achieved a high rate of disease remission and permitted prednisolone reduction in refractory or relapsing Wegener's granulomatosis. Adverse events were common but rarely led to treatment discontinuation.

Reduced folate carrier polymorphism determines methotrexate uptake by B cells and CD4+ T cells.

OBJECTIVE: To examine if polymorphism 80G --> A in the Reduced Folate Carrier (RFC) affects uptake of MTX in B- and CD4+ T-cells. METHODS: Mononuclear cells were isolated from peripheral blood of healthy persons. Real-time PCR was used to detect the RFC80 variants. FITC-labelled MTX was added to cells stimulated with Candida albicans or tetanus toxoid, and the uptake of MTX was measured by flow cytometry. A FITC-conjugated monoclonal antibody against RFC was used to detect the cellular RFC expression. RESULTS: Antigen-stimulated CD4+ T cells and B cells from individuals with the GG variant (n = 9) exhibited lower uptake of MTX than individuals expressing the AA variant (n = 8), or the GA variant (n = 8). No difference could be demonstrated between the three groups with respect to the expression of RFC by CD4+ T cells and B cells, and CD4+ T cells from individuals homozygous for the G allele exhibited lower uptake of MTX per receptor than CD4+ T cells from individuals homozygous for the A allele. CONCLUSION: MTX is taken up more efficiently via the A allele than via the G allele. This difference between the variant forms of RFC suggests that genotyping could be relevant for determining the relevant dosage of MTX in the treatment of neoplastic and autoimmune disease.

Insulin resistance in patients with rheumatoid arthritis: effect of anti-TNFalpha therapy.

OBJECTIVES: We undertook this study to test the hypotheses that patients with active rheumatoid arthritis (RA) are insulin resistant and that anti-tumour necrosis factor-alpha (TNFalpha) therapy improves not only the clinical state of these patients but also their glucose metabolism. METHODS: Nine RA patients with active disease and nine healthy subjects, matched for sex, age, and body mass index (BMI), underwent a hyperinsulinaemic euglycaemic clamp. The RA patients received anti-TNFalpha therapy with Humira(adalimumab) and had the insulin clamp re-evaluated after 8 weeks of treatment. RESULTS: Patients with RA had marked insulin resistance (glucose infusion rate (GIR) area under the curve (AUC) was 499+/-55 mg/kg in the RA group compared to 710+/-77 mg/kg in the control group; p<0.05). However, insulin sensitivity did not differ before and after 8 weeks of adalimumab therapy. The RA patients demonstrated a reduction in C-reactive protein (CRP) and interleukin-6 (IL-6) levels after the therapy as compared to pretreatment values, but there was no concomitant effect on plasma levels of TNFalpha. CONCLUSION: RA patients with active disease showed marked insulin resistance that was not influenced by anti-TNFalpha therapy despite a reduction in systemic inflammation during the treatment.

Methotrexate induces poly(ADP-ribose) polymerase-dependent, caspase 3-independent apoptosis in subsets of proliferating CD4+ T cells.

The mechanism of action of methotrexate (MTX) in autoimmune diseases (AID) is unclear. A pro-apoptotic effect has been demonstrated in mitogen-stimulated peripheral blood mononuclear cells (PBMC), but studies employing conventional antigens have disputed a pro-apoptotic effect. CD4+ T helper (Th) cells play a significant role in most AID. We therefore examined directly, by flow cytometry, the uptake of MTX by the T helper (Th) cells stimulated for 6 days with Candida albicans (CA) or tetanus toxoid (TT), and its consequences with respect to induction of apoptosis. While none of the resting Th cells took up MTX, nearly all the dividing Th cells did, and this abrogated further cell division. Among dividing Th cells, MTX induced an approximately sixfold increase over baseline levels in the proportion of apoptotic cells. This proportion could be reverted to baseline by the addition of folic acid. Exposure of CA-stimulated PBMC to MTX significantly increased their level of cleaved poly(ADP-ribose) polymerase (PARP), and a similar tendency was observed in TT-stimulated cells. Unlike CA and TT, the mitogen phytohaemagglutinin (PHA) induced proliferation of both CD4- and CD4+ T cells, and induced apoptosis in both undivided and divided Th cells. PHA-induced apoptosis involved activation of caspase-3 and the anti-apoptotic protein Bcl-2 in addition to PARP cleavage, suggesting that PHA induces apoptosis via different pathways than CA and TT. We suggest that the latter are more representative of stimulation with self-antigens in AID, and that a pro-apoptotic effect of MTX on self-antigen-stimulated Th cells contributes to the effect of MTX in the treatment of AID.

Magnetic resonance imaging for accelerated assessment of drug effect and prediction of subsequent radiographic progression in rheumatoid arthritis: a study of patients receiving combined anakinra and methotrexate treatment.

OBJECTIVES: By MRI to assess the efficacy of addition of anakinra for controlling synovitis and stopping erosive progression in patients with clinically active RA despite receiving methotrexate, and to determine the predictive value of MRI for subsequent radiographic erosive progression. METHODS: 100 mg anakinra subcutaneously/day was added to the treatment of 17 patients with clinically active RA despite methotrexate. MRI of the non-dominant wrist and 2nd-5th MCP joints (OMERACT evaluation) was performed at weeks 0, 12, and 36, and radiography of both hands and wrists (modified Sharp evaluation) at weeks 0 and 36. RESULTS: MRI synovitis scores were not significantly changed. Radiography of both hands and wrists after 36 weeks showed erosive progression in 11 patients, and MRI after 12 weeks in 10 patients. Nine of 10 patients with MRI progression at 12 weeks had radiographic progression at 36 weeks. Baseline MRI synovitis and erosion scores, but no clinical/biochemical parameters, correlated significantly with subsequent erosive progression. CONCLUSION: Addition of anakinra did not significantly reduce MRI signs of synovitis, and most patients had progressive joint destruction. Baseline MRI findings predicted subsequent radiographic erosive progression. Unilateral wrist and MCP joint MRI after 12 weeks had a similar sensitivity for detection of erosive progression as bilateral hand and wrist radiography after 36 weeks.

No evidence of parvovirus B19, Chlamydia pneumoniae or human herpes virus infection in temporal artery biopsies in patients with giant cell arteritis.

OBJECTIVES: Recent studies have suggested that infective agents may be involved in the pathogenesis of giant cell arteritis (GCA), in particular Chlamydia pneumoniae and parvovirus B19. We investigated temporal arteries from patients with GCA for these infections as well as human herpes viruses using the polymerase chain reaction (PCR). METHODS: Thirty temporal artery biopsies from 30 patients suspected of having GCA within a period of 1 yr were examined. Thirteen patients had classical GCA, two had biopsy-negative GCA, 10 patients had polymyalgia rheumatica and five patients had other conditions. DNA was extracted from frozen biopsies and PCR was used to amplify genes from Chlamydia pneumoniae, parvovirus B19 and each of the eight human herpes viruses: herpes simplex viruses HSV-1 and 2, Epstein-Barr virus, cytomegalovirus, varicella zoster virus and human herpes viruses HHV-6, -7 and -8. RESULTS: In all 30 biopsies, PCR was negative for DNAs of parvovirus B19, each of the eight human herpes viruses and C. pneumoniae. CONCLUSIONS: We found no evidence of DNA from parvovirus B19, human herpes virus or C. pneumoniae in any of the temporal arteries. These agents do not seem to play a unique or dominant role in the pathogenesis of GCA.

YKL-40 in giant cells and macrophages from patients with giant cell arteritis.

OBJECTIVE: YKL-40, a mammalian member of the family 18 glycosyl hydrolases, is secreted by activated macrophages at a late stage of differentiation. Macrophages are present in inflammation of the arterial wall and are thought to participate in the pathogenesis of giant cell arteritis (GCA). The aim of this study was to evaluate whether macrophages and giant cells of patients with GCA produce YKL-40, and whether serum YKL-40 concentrations are elevated in these patients. METHODS: Serum YKL-40 was determined by radioimmunoassay in 19 patients with GCA and 8 patients with polymyalgia rheumatica (PMR) who were followed up prospectively during 1 year of treatment with prednisolone. Immunohistochemical staining for YKL-40 was performed in temporal artery biopsy samples that were obtained before treatment. RESULTS: In the arteritic vessels of patients with GCA, positive staining for the YKL-40 antigen was found in CD68+ giant cells and mononuclear cells located in the media. Macrophages located in the adventitia and intima were negative for YKL-40. At the time of diagnosis, patients with GCA had an increased median serum level of YKL-40 (256 microg/liter; P<0.01) compared with healthy age-matched controls (median 118 microg/liter), and the serum level of YKL-40 decreased to normal levels during prednisolone treatment (-38% after 1 month; P<0.001). Most patients with PMR had normal serum YKL-40 levels (median 158 microg/liter) and had no changes in the serum YKL-40 levels during prednisolone treatment. The observed changes in serum YKL-40 did not always parallel the changes in serum C-reactive protein levels and erythrocyte sedimentation rate during the 1-year study period. CONCLUSION: YKL-40 is found in CD68+ giant cells and mononuclear cells in the media of arteritic vessels of patients with GCA, and the concentration of serum YKL-40 may reflect the local activity of these cells in the inflamed artery.

Anti-neutrophil cytoplasm autoantibodies (ANCA). The need for specific and sensitive assays.

Anti-neutrophil cytoplasm antibodies (ANCA) are a group of autoantibodies primarily associated with systemic vasculitis. Hitherto, the method of choice for ANCA detection has been indirect immunofluorescence (IIF). By this method two major patterns can be seen: a cytoplasmic pattern (cANCA) or a perinuclear pattern (pANCA). The cANCA pattern is most often caused by antibodies directed against proteinase-3 (PR3) and in rare cases it is caused by anti-myeloperoixdase (MPO) antibodies. The pANCA pattern can de caused by antibodies directed against a large group of proteins i.e. MPO, lactofenin and bactericidal/permeability-increasing protein. Often there is a discrepancy between the results obtained by IIF and those reported from the use of assays with purified antigens. This causes confusion. Until now only anti-PR3 and anti-MPO have been found of any clinical value. Therefore, it would be more proper to use assays with these highly purified antigens instead of an unspecific method like IIF.

Clinical evaluation of a capture ELISA for detection of proteinase-3 antineutrophil cytoplasmic antibody.

Detection of antineutrophil cytoplasmic antibodies (ANCA) has become a useful tool in the diagnosis of Wegener's granulomatosis and microscopic polyangiitis. However, the results obtained with indirect immunofluorescence (IIF) and by ELISA for ANCA demonstration do not always correlate. A possible explanation for this finding could be that proteins are denatured during the process of antigen purification or during coating onto the solid phase. To avoid this possibility, a monoclonal antibody to PR3 that is precoated on the plate can be used. In the present study we have used the monoclonal antibody (MoAb) 4A3 for the capture of PR3 in an ELISA, and a clinical evaluation of the diagnostic properties of the new capture ELISA has been made. The sensitivity of the capture PR3-ANCA ELISA was 85% in a material of c-ANCA positive sera. A specificity of 90% was obtained in analyses from patients having various forms of glomerulonephritis. There was a significantly higher diagnostic sensitivity of the capture PR3-ANCA ELISA (85%) compared to c-ANCA by IIF (58%) in patients with Wegener's granulomatosis with renal involvement. Capture PR3-ANCA and direct ELISA for MPO-ANCA together gave a diagnostic sensitivity of 98%, versus 75% using IIF. In conclusion, the capture PR3-ANCA ELISA seems to be a valuable tool in the diagnosis of Wegener's granulomatosis with renal involvement. Preliminary data suggest that the technique may have an advantage over direct ELISA for PR3-ANCA, as well as in the follow-up of c-/PR3-ANCA associated vasculitides. However, further prospective studies are needed to clarify this premise.

Complexes between proteinase 3, alpha 1-antitrypsin and proteinase 3 anti-neutrophil cytoplasm autoantibodies: a comparison between alpha 1-antitrypsin PiZ allele carriers and non-carriers with Wegener's granulomatosis.

To test the hypothesis that anti-neutrophil cytoplasm autoantibodies (ANCAs) interfere with the functions of proteinase 3 (PR3) (the Wegener autoantigen) and alpha 1-antitrypsin (alpha 1AT), complexes of PR3/alpha 1 AT and PR3/PR3-ANCA-IgG were assayed Plasma samples were obtained from 44 patients with Wegener's granulomatosis (WG): 34 had active disease (88% ANCA positive) whereas 10 patients were in remission (20% ANCA positive). Plasma samples from 14 of the patients with active disease were also available at the time of remission. The complexes of PR3/alpha 1 AT and PR3/PR3-ANCA-IgG were detected by capture enzyme-linked immunoassays (ELISAs) alpha 1 AT deficiency was evaluated by determining PiZ alleles by ELISA. Eight (18%) of the patients were PiZ positive. The frequency of this alpha 1-antitrypsin phenotype in the Scandinavian population is 4.7% (P < 0.001). The median PR3/alpha 1AT complex level in the PiZ-positive group with active disease (n = 5) was similar to the level in the PiZ-negative group with active disease. During remission the median level for the PR3/alpha 1AT complex was significantly higher than in the acute group (P < 0.001) including both PiZ-positive and PiZ-negative patients. No difference between PiZ positivity and PiZ negativity could be found in the remission group. PR3/PR3-ANCA-IgG complexes were found in patients with acute disease as well as in patients in remission, in almost equal frequency. This complex was also present in 13/18 ANCA-negative samples from patients in remission. Finally, purified IgG fractions from WG patients were examined for their capacity to inhibit binding between PR3 and alpha 1AT. An effect on the binding between PR3 and alpha 1AT by PR3-ANCA could not be demonstrated. Thus, our results do not support the hypothesis that PR3-ANCA interferes with the binding between PR3 and alpha 1AT. However, the high prevalence of the PiZ alleles among WG patients suggests that an imbalance between proteinases and alpha 1AT may be of importance in this disease. The clinical usefulness of both the PR3/alpha 1AT and the PR3/PR3-ANCA-IgG complexes and the possible influence on ANCA detection need to be examined in prospective longitudinal studies.

Anticardiolipin antibodies and lipoprotein (a) levels in patients with chronic renal failure treated with dialysis: associations with atherothrombotic disease.

The present study evaluated the importance of anticardiolipin antibodies (ACA) and lipoprotein (a) (Lp(a)) as markers of atherothrombotic disease in a retrospective study of patients on maintenance hemodialysis (HD) or peritoneal dialysis (PD). ACA and Lp(a) were measured in 22 patients on PD, and 64 on HD. Three patients were ACA IgM seropositive, whereas none were ACA IgG seropositive. The mean number of previous atherothrombotic events was 2.0 (1-3) in ACA seropositive patients, as compared to 0.7 (0-4) in ACA seronegative patients. The mean Lp(a) level was 56.7 mg/dl (3.0-217.7) in PD patients and 38.8 mg/dl (2.0-255.6) in HD patients (n.s.). Levels of Lp(a) greater than 30 mg/dl were not significantly associated with a history of atherothrombotic events, but all patients who had suffered a myocardial infarction or cerebrovascular insult had Lp(a) levels above 30 mg/dl. We conclude that ACA seropositivity is rare. All ACA seropositive patients had suffered atherothrombotic disease in the current study, whereas all patients with myocardial infarction or cerebrovascular insult had Lp(a) levels above 30 mg/dl.

Clinical correlates and substrate specificities of antibodies exhibiting neutrophil nuclear reactivity--a methodological study.

In a serological laboratory with a routine service for determining autoantibodies to human neutrophils, antibodies giving a selective or preferential reaction with the nucleus or perinuclear area of neutrophils are not uncommon. The aim of this study was to look for clinical correlates with the presence of such neutrophil-reactive autoantibodies. The specificity of such antibodies for nuclear or cytoplasmic antigens was studied in 65 consecutive sera displaying nuclear/perinuclear reactivity at a titre of at least 80 using the indirect immunofluorescence technique (IIF) on ethanol-fixed leucocytes. The sera were also investigated by IIF on formalin-acetone fixed leucocytes and on HEp-2 cells. ELISA techniques were used to measure antibodies to azurophil granule constituents (ANCA), purified myeloperoxidase (MPO-ANCA), and lactoferrin (LF-ANCA). Furthermore a qualitative spot immunoassay was used for the detection of antibodies to alpha, beta, and gamma fractions, and the nuclear fraction of neutrophils, purified proteinase 3 (PR3), MPO, enolase, lysozyme, elastase, lactoferrin, and cathepsin G. The diagnoses linked to such GS-ANA/pANCA positivity were arthritides, vasculitides, inflammatory bowel disease and chronic hepatic conditions. MPO was the main antigen recognized in the vasculitis group, but apart from that, rather limited antigen reactivity was demonstrable by these techniques, lysozyme being the most frequently recognized autoantigen in patients with arthritides. Human lymphocytes served as a suitable control substrate when distinguishing between GS-ANA/pANCA and ANA, whereas HEp-2 cells usually could not be used if both classes of antibodies were present in a sample. Furthermore, formalin-acetone fixation is not recommended for routine use.

Vitamin D3 metabolism in patients with rheumatic diseases: low serum levels of 25-hydroxyvitamin D3 in patients with systemic lupus erythematosus.

1,25-dihydroxyvitamin D3 (1,25(OH)2 D3) has been shown to modulate lymphocyte activation in vitro. Through binding to specific receptors 1,25-(OH)2 D3 inhibits proliferation, immunoglobulin production and the release of cytokines. Moreover, 1,25-(OH)2 D3 is efficiently produced by activated monocytes. These findings suggest that 1,25-(OH)2 D3 may play a role as a regulator of immunological activation. Consequently, we found it of interest to study the serum levels of the two major metabolites of vitamin D3 in patients with systemic lupus erythematosus (SLE) (n = 21), rheumatoid arthritis (RA) (n = 29) and osteoarthritis (n = 12). In patients with SLE the levels of 25-OH D3 were below those of the healthy controls (p = 0.0008) and OA (p = 0.0168). The levels 1,25-(OH)2 D3 corresponded to normal levels. There were no significant correlations between 25-OH D3 levels and clinical or paraclinical disease manifestations. Further, the phenotypic distribution of Gc-globulin, which binds vitamin D3 metabolites in circulation, was normal. The serum concentrations of 1,25-(OH)2 D3 and 25-OH D3 in patients with RA and OA corresponded to those of the controls. Although the cause of the reduced 25-OH D3 levels in SLE patients is unclear, possible beneficial effects of administration of vitamin D to these patients should be considered.

Screening for anti-neutrophil cytoplasmic antibodies (ANCA): is indirect immunofluorescence the method of choice?

Detection of ANCA has become an important tool for the diagnosis and monitoring of disease activity in Wegener's granulomatosis (WG). Unfortunately, a group of sera positive by the standard method for ANCA detection, indirect immunofluorescence (IIF), are negative when more specific tests with purified proteins are used. In order to examine this discrepancy we examined groups of sera selected for being (i) C-ANCA-positive by IIF; (ii) positive in proteinase 3 (PR3)-ANCA ELISA; and (iii) from 24 patients with WG. The following assays were used: IIF, PR3-ANCA ELISA and capture PR3-ANCA ELISA using MoAbs against PR3. Furthermore, since granule enzymes are released during coagulation, we also measured ANCA in complex with PR3. To test if granule enzyme release had any influence on ANCA detection, both serum and EDTA-plasma were collected from a patient with active WG. No difference, however, was found. In the IIF-positive group (n = 60) 68% of the sera were positive in PR3-ANCA ELISA, 86% in capture PR3-ANCA ELISA and 80% were positive for the PR3/IgG-ANCA complex. In the PR3-ANCA ELISA group (n = 105) 88% of the sera were positive by IIF, 98% in capture PR3-ANCA ELISA and 53% in the PR3/IgG-ANCA assay. To evaluate the tests clinically sera from 24 patients with WG were examined. In the remission group (n = 10) two patients were positive by IIF, four in the PR3-ANCA ELISA, and five in the capture PR3-ANCA ELISA. Fourteen had active disease, and in this group 11/14 were positive by IIF, 10/14 in PR3-ANCA ELISA and 12/14 by capture-ELISA. The correlation between IIF and capture PR3-ANCA ELISA titre (r = 0.72, P = 0.0095) was better than between PR3-ANCA ELISA and IIF (r = 0.56, P = 0.043). It is concluded that the capture PR3-ANCA ELISA is more sensitive than PR3-ANCA ELISA, and that the capture ELISA can be used for screening of PR3-ANCA.

Measurements of proteinase 3 and its complexes with alpha 1-proteinase inhibitor and anti-neutrophil cytoplasm antibodies (ANCA) in plasma.

Wegener's granulomatosis (WG) is a systemic vasculitis which is diagnosed on clinicopathological findings. The diagnosis may be aided by the presence of anti-neutrophil cytoplasm antibodies (ANCA). In WG, ANCA are primarily directed to proteinase 3 (PR3), a serine protease of the azurophilic granules of the neutrophilic granulocyte. The main plasma inhibitor of PR3 is alpha 1-proteinase inhibitor (PI). To study if free PR3 or complexes between the enzyme and PI or PR3 and ANCA could be found in the plasma from patients with WG we have developed three ELISA systems for the detection of these complexes and free PR3. In all three assays monoclonal antibodies against PR3 were used as capture antibodies. After incubation with plasma, free PR3 was detected by affinity purified rabbit anti-PR3 followed by alkaline phosphatase-labelled swine anti-rabbit IgG. Serial dilutions of purified PR3 was used as standard. The detection limit was 3 ng/ml. PR3 complexed with PI was measured by rabbit anti-PI antibodies and alkaline phosphatase-labelled swine anti-rabbit IgG. Pre-formed in vitro complexes of PR3/PI in serial dilutions were used as standard. The detection limit of this assay was 1 ng/ml. PR3/IgG-ANCA complexes were detected by alkaline phosphatase labelled goat anti-human IgG. A positive plasma sample in serial dilutions was used as standard. Plasma samples from nine patients with WG, eight patients with fever of infectious origin without evidence of vasculitis and ten healthy donors were examined by these methods. Free PR3 could not be found in any of the plasma samples. PR3/PI complexes were detected in healthy donors at levels between 41-85 ng/ml. All WG patients, both active and inactive, had PR3/PI concentrations above this level, and so had all patients with fever. PR3/IgG-ANCA was found in three of the patients with WG, two being ANCA negative with inactive disease and one was ANCA positive with active disease. Thus, the developed methods can be useful for future studies of the clinical relevance of these complexes in patients with WG and possibly other vasculitides.