Our results suggest that genetic polymorphisms in the folate metabolic pathway and MTX transporters modify the toxicity but not the efficacy of MTX treatment.

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Soluble low Km 5'-nucleotidases have been purified from human cultured T- and B-lymphoblasts to compare their properties and to examine the mechanism of different rates of nucleotide dephosphorylation. The enzyme from B-lymphoblasts (MGL-8) was 4385-fold purified with a specific activity of 114 mumol/min/mg, while the enzyme from T-lymphoblasts (CEM, MOLT-4) was 4355-fold purified with a specific activity of 35 mumol/min/mg. The activity of both enzymes have an absolute requirement for Mg++. The B-cell enzyme has maximum activity with Mg2+ > Mn2+ > Co2+, while the T-cell enzyme had maximum activity with Co2+ > Mn2+ > Mg2+. The optimum activity was at pH 7.4-9.0 for the B-cell enzyme and pH 9.0 for the T-cell enzyme. Substrate specificity was the same for both enzymes with the following relative Vmax values: CMP > UMP > dUMP > dCMP > dAMP > IMP > GMP > dIMP > dGMP. The Km values for AMP and IMP were 12 and 25 microM for the B-cell enzyme, and 7.0 and 12 microM for the T-cell enzyme. ATP and ADP are competitive inhibitors of these enzymes with apparent Ki values of 100 and 20 microM for the B-cell enzyme, and 44 microM and 8 microM for the T-cell enzyme, respectively. The apparent molecular mass by gel filtration column chromatography is 145 kD for the B-cell enzyme and 72 kDa for the T-cell enzyme. The subunit molecular masses by Western blots are 69.2 kD for both enzymes. These properties suggest that the B-lymphoblast enzyme is identical or similar to the enzyme from human placenta. However, the T-cell enzyme has some different properties. We conclude that these differences plus a lower content of low Km 5'-nucleotidase in T-cells may account for the decreased ability of T-lymphoblasts to dephosphorylate nucleotides and may contribute to the selective cytotoxicity of deoxyribonucleosides for T-lymphoblasts as compared to B-lymphoblasts.

Amyloid A (AA) (secondary) amyloidosis represents a severe complication of chronic inflammatory diseases. Since pathogenic mechanisms point to the central role of interleukin 6 (IL-6) in the process of amyloid AA generation, IL-6 blockade seems an attractive therapeutic option. We report a case of a patient with polyarteritis nodosa complicated by AA amyloidosis treated with tocilizumab.

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BackgroundIn patients with rheumatoid arthritis (RA), early diagnosis and adherence to the treat to target recommendations (T2T) limit RA progression and improve patients’ quality of life.1 However, the implementation of T2T has always been a challenge, and real-life data are lacking. Slovenia has 40% less rheumatologists per capita than the European Union average, which makes the implementation of management guidelines even more challenging.ObjectivesTo determine the incidence of RA and the proportion of patients with incident RA in whom first rheumatology assessment was done within the recommended time frame.MethodsWe analysed the prospectively collected data of adult patients diagnosed with RA during years 2014 to 2016 at the Rheumatology Department of the University Medical Centre Ljubljana, Slovenia. The department provides rheumatology services to a well-defined region with a population of 704.000 adult residents. Dates were recorded for inflammatory joint symptom onset, referral to rheumatologist, first rheumatologic assessment and initiation of DMARD therapy. The percentage of patients assessed by a rheumatologist and/or treated with a DMARD within 12 weeks of symptom onset and the median times for delay were then calculated.ResultsBetween 1 January 2014 and 31 December 2016, 341 incident cases of RA (75% females, median age 61.9 (IQR 52–75.4) years) were identified, resulting in an annual incidence rate of 16/100.000 population (in females: 23.6/100.000; in males 8.3/100.000). Most patients (78.6%) were referred to our early interventional clinic. The median time from symptom onset to consultation was 12.9 (IQR 4.4–26.1) weeks, median time from referral to consultation was 1 (IQR 1–3) day. Median DMARD treatment delay was 16.6 (IQR 8.9–33.3) weeks. Within 12 weeks of symptom onset, 161 (47.2%) new RA patients were examined by a rheumatologist and 123 (36.1%) were started on DMARD therapy.ConclusionsOur prospective data support the recent reports that uncovered a decrease in RA incidence.2 Moreover, despite the lack of rheumatologists and the heavily protracted nationwide waiting times for first rheumatologist assessment, our early interventional clinic enables us to recognise and manage substantial percentage of RA patients within the recommended time frame.References[1] Monti S, et al. Rheumatoid arthritis treatment: the earlier the better to prevent joint damage. RMD Open2015;1(Suppl 1):e000057. doi:10.1136/rmdopen-2015-000057[2] Abhishek, et al. Rheumatoid arthritis is getting less frequent—results of a nationwide population-based cohort study. Rheumatology2017;56:36–744–7.Disclosure of InterestNone declared

BackgroundIgA vasculitis (IgAV) is commonly marginalized disease in adults. Clinical data are scarce and mostly limited to patients with significant renal disease. Predictors of severity in acute adult IgAV are unknown.ObjectivesTo create a simple semi-quantitative score predicting the severity of adult IgAV and to aid the management of adult IgAV.MethodsWe performed a paper chart review of adult, histologically proven IgAV cases, diagnosed between 01.01.2010 and 31.12.2014 at our secondary/tertiary rheumatology center. The disease activity was assessed using BVAS-3. Predictors of severe disease were identified and an IgAV severity score (IgAVSS) was constructed.ResultsDuring the 60-month observation period, 129 new IgAV cases (58% male) were identified. The median (interquartile range (IQR), range) age was 64.2 (40.4–77.3, 18-92) years. Skin, gastrointestinal (GI), renal and joint involvement was present in 129 (purpura limited to lower limbs in 54.3% and generalized above waist in 45.7%), 48 (severe in 13), 65 (severe in 16) and 58 patients, respectively. Males and patients with generalized skin purpura had more severe disease (p=0.019 for male vs. female gender and p=0.0005 for generalized vs. limited purpura). Patients aged 45–75 years had more commonly severe GI and severe renal disease than younger (<45) or older (>75) ones (38.5% vs 31.6% vs 12.5% in case of severe GI disease and in 40.9% vs 9.5% vs 22.7% in case of severe renal disease respectively). The IgAVSS was constructed by assigning weights to patient age, gender and extent of purpura at presentation. It is a simple sum of the three domains (Table 1A). IgAVSS rendered good delineation between mild uneventful and severe IgAV when the cut off was set at ≥1.5 points. The difference in BVAS-3 between IgAVSS <1.5 and IgAVSS ≥1.5 was significant, p=0.003. (Table 1B).Table 1A. IgAVSSB. Performance of the IgAVSSCharacteristicIgAV scoreNo. of pts.GISevere GIRenalSevere renalArthritisBVASGenderMale1 point<1.568193294149 (3–14)Female0 points≥1.5 61291036121214 (6–19)PurpuraGeneralized1 pointP value–0.0290.0380.0780.02910.003Limited0 pointssevere GI – bloody diarrhea or ileus or surgical intervention; severe renal – acute renal failure or nephrotic syndromeAge<45 years0 points45–75 years0.5>75 yearsIgAVSS = gender + purpura + age. ConclusionsGender, patient age and extent of purpura predict the severity of adult IgAV. We propose a semi quantitative score the IgAVSS which is calculated based on clinical characteristics only as a decision making aid to the physician in a busy outpatient clinic setting to distinguish patients who might have a more severe disease requiring hospital management from those who can be managed on the outpatient basis.Disclosure of InterestNone declared

Background La/SSB is a phosphoprotein that associates with various small RNA molecules. It has been found that the primary phosphorylation site of the molecule during various physiological processes is in Ser366. Objectives To determine whether the phosphorylation state of Ser366 could affect the antigenicity and the recognition of the protein by antibodies from patients with primary Sjögren's syndrome (pSS). Methods Peptides 349-368aa and phos349-368aa (with the Ser366 residue phosphorylated) were synthesized. Sera with anti-La specificity from 30 patients with pSS and sera from 19 normal individuals were examined against the two synthetic peptides in ELISA. The antibody specificity against the epitopes was tested with homologous and heterologous inhibition assays. Results Of pSS sera 23% reacted against the 349-368aa peptide. Sera binding to unphosphorylated peptide reacted also with phos349-368aa. Although the same sera gave a positive reaction against both peptides, the optical density values received from antibodies to phos349-368aa were higher, indicating a higher concentration or stronger affinity. When phos349-368aa was used as soluble inhibitor, in homologous inhibition the reactivity was almost completely abolished (92%). In contrast, when the unphosphorylated peptide was used as inhibitor, the reactivity of sera against phos349-368aa was only partially reduced (35%), indicating that sera from these patients possess two distinct groups of antibodies: one against the unphosphorylated and one against the phosphorylated epitope. Conclusion The phosphorylation of the serine366 residue resulted in a significant increase in antibody binding on epitope 349-368aa of La/SSB. These observations might explain the increased antigenicity of La/SSB autoantigen in various pathological situations in which phosphorylation may occur. 2 Surface-bound immune complexes containing antibodies to collagen type II induce production of TNF-α α, IL-1β β and IL-8 from monocytes via Fcγ γRII