Autoantibodies' titre modulation by anti-BlyS treatment in systemic lupus erythematosus

Deciphering the clinical significance of longitudinal antiphospholipid antibody titers

In antiphospholipid syndrome (APS), the risk of clinical manifestations increases with higher titers of antiphospholipid antibodies (aPL). Despite the adoption of aPL titers in the classification approach to aPL-positive subjects, the value of longitudinal monitoring of those titers in the follow-up is still debated, being well studied only in systemic lupus erythematosus (SLE). The literature suggests that the rate of aPL positivity decreases during follow-up in primary APS, estimating that seroconversion occurs in between 8.9 and 59% of patients over time. Negativisation of aPL occurs more frequently in asymptomatic aPL carriers than in patients with full-blown APS as well as in subjects with single aPL positivity or low aPL antibody titers. In patients with SLE, aPL typically behave fluctuating from positive to negative and back again in the course of follow-up. The few studies assessing the longitudinal course of aPL positivity with no associated systemic connective tissue disease reported a progressive decrement of aPL titers over time, in particular of antibodies against β2 glycoprotein I (antiβ2GPI) and cardiolipin (aCL) of IgG isotype. After a thrombotic event, aPL titers tend to decrease, as emerged from cohorts of both primary and secondary APS. Hydroxychloroquine has been identified as the most effective pharmacological agent to reduce aPL titers, with multiple studies demonstrating a parallel reduction in thrombosis rate. This review addresses available evidence on the significance of aPL titer fluctuation from clinical, therapeutic and pathogenic perspectives.

Predictive value of the Adjusted Global Anti-Phospholipid Syndrome Score on clinical recurrence in APS patients: A longitudinal study

OBJECTIVE

To assess the effect of the average adjusted global APS score (aGAPSS) over time on recurrence of clinical manifestations in APS patients through a retrospective longitudinal study.

METHODS

The study included 200 patients with APS. The aGAPSS was calculated for each patient at baseline and on a yearly basis for either up to 6 years (minimum 3 years) or just before the clinical event in patients who experienced clinical recurrence. The mean score per patient was computed. In patients under vitamin K antagonists (VKA) the percentage of time spent within the therapeutic range (TTR) was calculated. Cox-regression analysis was performed to determine the cut-off value of the aGAPSS with the strongest association with clinical recurrence.

RESULTS

Higher average aGAPSS values were found in patients who experienced clinical recurrence in comparison to patients who did not [8.81 (95% C.I. 7.53-10.08) vs 6.38 (95% C.I. 5.64-7.12), p = 0.001], patients with thrombotic recurrence compared to patients with obstetric recurrence [9.48 (95% C.I. 8.14-10.82) vs 4.25 (95% C.I. 0.85-7.65), p = 0.006], and patients with arterial thrombosis compared to patients with venous thrombosis [10.66 (S.D. 5.48) vs 6.63 (S.D. 4.42), p = 0.01]. aGAPSS values > 13 points were associated with the highest risk of recurrence in multivariate analysis [HR = 3.25 (95% C.I. 1.93-5.45, p < 0.0001]. TTR was not statistically different between patients who had thrombosis recurrence and patients who had not.

CONCLUSIONS

Our data support the role of periodic (annual) monitoring of the aGAPSS score in predicting clinical recurrence in patients with APS.

Clinical Delphi on aPLnegativization: report from the from the APS Study Group of the Italian Society for Rheumatology (SIR-APS)

The rate of antiphospholipid antibodies (aPL) negativization in antiphospholipid syndrome (APS) patients is uncertain, but it is estimated to be as high as 8%. Currently, a consensus definition of aPL negativization is lacking, as well as international recommendations on how to approach treatment in patients with a persistent aPL negative seroconversion. Evaluate the clinical approach and level of consensus among experts from the APS Study Group of the Italian Society for Rheumatology (SIR-APS) in different clinical scenario. Experts of SIR-APS were contacted using a survey methodology. A structured survey was circulated among 30 experts.Up to 90% of the interviewed experts agreed on defining aPL negativization as the presence of two negative determinations, one year apart (90%).Almost full consensus exist among experts in some clinical settings, including: a) the role of aPL negativization in the management of a thrombotic event determined by concomitant presence of cardiovascular risk factors, both modifiable and not modifiable (90%); b) approach to young patients with triple aPL positivity who experienced pulmonary arterial thrombotic event and tested negative for aPL detection after five year of vitamin K antagonist (VKA) treatment (90%); c)the use of "extra criteria" aPL antibodies testing before pondering VKA suspension (93%). A substantial agreement exists among expert on how to define aPL negativization. VKA suspension should be embraced with extreme caution, particularly in case of previous thrombotic events and/or triple aPL positivity. Nevertheless, VKA cessation might be considered when risk factors are carefully monitored/treated and the presence for "extra criteria" is ruled out.