Background and Aims

Hypocomplementemia in rheumatoid arthritis (RA) has been associated to higher inflammatory disease activity, more erosive disease and most frequent extra-articular involvement (such as pleuropulmonary complications, vasculitis, rheumatoid nodules or infection), being all of the above associations also related to seropositivity for rheumatoid factor (RF) or anti-CCP antibodies. Our objective is to explore if hypocomplementemia in RA independently of seropositivity is associated with a more aggressive disease.

Methods

We searched for patients with RA diagnosis and RF+ (>15 UI/mL) and hypocomplementemia C3 (<84 mg/dL) in 2017, as well as patients with RF+ but normal levels of C3 (>84 mg/dL) and C4 (>14 mg/dL) in the same period as controls. Demographic, biochemical, clinical ( and therapeutic were obtained from medical records. Differences between variables were analysed using Student-t or Chi-square tests.

Results

25 RA patients with RF+ and hypocomplementemia C3 (+/-C4) and 50 RA controls with RF+ and normal complement levels were identified. Basal characteristics (sex, age, disease duration) were similar in both groups. All biochemical, clinical and therapeutic variables were comparable between both groups except for higher levels of CRP in patients with hypocomplementemia (Table 1).

Conclusions

The present study does not find differences between patients with seropositive RA with low complement levels and those with normocomplementemia in terms of a more aggressive disease, cardiovascular comorbidity or inflammatory burden, except for higher CRP levels. This findings support that clinical associations of hypocomplementemia in RA are the same as those of RF seropositivity (to which it is associated).

Background and Aims

The anti-phosphatidylserine prothrombin antibodies (anti-PS/PT) have gained great interest in recent years for their role in the antiphospholipid syndrome as well as for their possible value as a surrogate marker for the evaluation of lupus anticoagulant.

AIMS: To study the presence of anti-PS / PT among patients with APS clinic. To improve the clinical characteristics of the isolated positive patients for anti PS / PT and lupus anticoagulant as well as the psitics for both markers.

Methods

We studied 300 patients who met the clinical APS classification criteria from the H12/2017 historical cohort of 1756 patients with suspected APS studied in 2017 at the Hospital 12 de Octubre..
Anti PS/PT IgG/M (ELISA-Werfen) and all the antibodies of the Sydney consensus: LA, ACL (IgG/M), aB2GP1(IgG/M) were evaluated.
To avoid interference from other autoantibodies, only isolated positive patients for LA and anti PS/PT (IgG/M) were compared. In adition, positive only for both markers (aCL and aB2GP1 negative) also were analized.

Results

A total of 77 patients (25.7%) were positive for at least one aPL. (Combinations of positivities in Venn-diagram). Isolated positive patients for anti PS/PT were 17 and for LA, 21. Only 7 patients were simultaneously positive for LA and anti PS/PT (negative for others aPL).

The 35% of anti-PS/PT positive-patients in presented gestational morbidity versus 10% on LA-patients (OR:4.91, 95% CI:1.04-23.2). LA-positive patients had a greater deep vein-thrombosis prevalence (66.7% vs 23.5%; OR:6.50, 95% CI:1.54-27.5).

Conclusions

The determination of anti PS/PT should be mandatory, at least, in patients with gestational morbidity.

Background and Aims

The development of new automated ANA screening techniques, based in simultaneous detection of autoantibodies using an array of purified/recombinant antigens has allowed identify patients who are isolated positive for some autoantibodies and who nevertheless do not have the clinic associated with these antibodies . The anti-RNP-A antibodies have very low specificity and are very often founded in the general asymptomatic population.

GOAL: To determine if these anti-RNP-A“false positives” could be identifying people who later developed an immune-mediated inflammatory disease (IMID).

Methods

310 patients isolate positive for anti RNP-A (BioPlex® 2200) and negative for ANA-immunofluorescence in the period 2012-2015 were followed-up prospectively until October 2019 (3-7 years)

Results

78 patients (25%) had previous IMID diagnosis (38.5% RA, 11.5% IBD-associated spondyloarthritis, 9% SLE, 7.7% APs, 6.4% PMR, 5% Sjögren's syndrome, 3.8% EspA-ax, and 18.1% others.
Of the 232 patients without IMID, in 76 (33%) ANA was request by routine and no follow-up was performed. In the other 156 (67%) during the follow-up, a diagnosis of IMID was reached in 23 patients (14.7%). Only in 9 (5.8%) was diagnosed an ANA-associated connective disease (1 SLE, 1 SLE induced by anti-TNFα, 2 EMTC, 2 SAF, 3 Sjögren), The other 14 (8.9%) had other autoimmune diseases not ANA-associated (5 APs, 3 RA, 2 PMR, 1 EspA-ax, 3 vasculitis). The others 133 patients (85.3%) continued without IMID

Conclusions

Our series shows only a small percentage of patients with isolated anti-RNP + get to develop an immune-mediated disease over several years of follow-up.