We report a case of 63-year-old Chinese man, having a history of anti-myeloperoxidase (MPO) antibody anti-neutrophil cytoplasmic antibody (ANCA)-associated pulmonary-renal syndrome 9 years ago, presented with second episode of rapidly progressive glomerulonephritis (RPGN) and alveolar haemorrhage compatible with anti-glomerular basement membrane (GBM) disease. In first presentation, his anti-GBM antibody was negative. This time, anti-MPO antibody was negative, but anti-GBM antibody was positive. The long interval of sequential development of anti-GBM disease after ANCA-associated vasculitis in this patient may provide clues to the potential immunological links between these two distinct conditions. Clinicians should be aware of such double-positive association.

Thresholds for disease activity statuses and response to treatment for PDAS1 and PDAS2 have been established. They have comparable agreement to assessor-based criteria.

This case report described a 40-year-old lady presented with fever, headache, arthralgia, myalgia, and impaired liver function after returning from the Philippines. Chikungunya virus (CHIKV) and dengue serology were negative. Eight weeks after initial presentation, she experienced inflammatory polyarthritis mimic rheumatoid arthritis. This time CHIKV-IgM was detected, together with a >4-fold rise of CHIKV-polyvalent-antibody titre. The first CHIKV-IgM negative sample was reexamined and was CHIKV-PCR positive. CHIKV infection was confirmed and diagnosis of CHIKV-related arthritis was made. A quarter of CHIKV infected individuals develop post-CHIKV rheumatisms that affect quality of life and may need treatment with Disease Modifying Antirheumatic Drugs. This case highlights the importance of considering CHIKV infection in patients present with symmetrical polyarthritis particularly after travel to endemic regions. Testing of both CHIKV acute and convalescent-phase serum for CHIKV antibodies and PCR is recommended in suspicious case.

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BackgroundTreat-to-target is the standard of care in rheumatoid arthritis (RA). Integral to this is the regular assessment of disease activity. Several tools have been developed and validated to allow patients with RA to self-assess disease activity. One of these tools is the Patient-derived Disease Activity Score (PDAS). Two versions pf PDAS are available: PDAS1 and PDAS2. PDAS-2 is a composite score that includes patient global assessment of disease activity (PGA), modified health assessment questionnaire (MHAQ), patient self-assessed 28 swollen joint count (ptSJC28) and early morning stiffness score (EMS). PDAS2 correlated with DAS28ESR and Clinical Disease Activity Index (CDAI).ObjectivesIn order to reduce patient burden, we developed a simplified PDAS2 (sPDAS2) by removing the need to assess EMS.MethodsData from 311 patients with established RA were analysed. The original model for calculating PDAS2 was: PDAS2 = 2.667 + [(0.021 x PGA) + (0.483 x MHAQ) + (0.033 x patient 28 SJC) + (0.002 x EMS)]. Linear regression was used to develop a sPAS2 using DAS28ESR as a dependent variable and including PGA, MHAQ and ptSJC28. R-squares were used to examine the statistical model fit of sPDAS2 compared with PDAS2. sPDAS2 was further validated using data from a different cohort of 204 patients with established RA. Correlation of sPDAS-2 with DAS28 and CDAI was examined to assess criterion and construct validity.ResultsBased on data from 311 patients with RA. The following model for sPDAS2 was developed: sPDAS2 =2.447 + 0.028 x PGA + 0.422 x HAQ + 0.053 x patients 28SJC.The R-square for PDAS2 (including EMS) was 0.601. R-square for sPDAS (without the EMS) was 0.594. A difference of 0.007 indicating minimal loss of statistical fit.Using data from a different cohort of RA patients. sPDAS2 correlated well with DAS28ESR (r=0.72, p<0.001) and CDAI (r=0.74, p<0.001) demonstrating criterion and construct validity.ConclusionsA sPDAS2 has been developed and validated for patients with RA to self-assess disease activity. The components of sPDAS2 included PGA, mHAQ and ptSJC28 and do not require assessment of early morning stiffness.AcknowledgementThe original developed of PDAS was supported by a grant from Arthritis Research UK. The CREATE Centre is funded by Arthritis Research UK and Health and Care Research Wales.Disclosure of InterestNone declared