THU0264 MYELOID MALIGNANCIES, SYSTEMIC AUTOIMMUNE DISEASES AND CARDIOVASCULAR RISK: AN UNDER-REPORTED ASSOCIATION?

Background:

The association between systemic autoimmune diseases (ADs) and lymphoproliferative malignancies is well established; nonetheless, few studies have investigated the prevalence and prognostic impact of myeloid malignancies on systemic autoimmune conditions.

Objectives:

To investigate the frequency of myeloid malignancies (i.e myelodysplastic syndrome (MDS) and chronic, either Philadelphia-positive or Philadelphia-negative, myeloproliferative disorders (MPNs)) in patients with ADs and their influence on the ADs clinical course and vice-versa.

Methods:

A retrospective systematic search through the electronic health records of the patients admitted at our Rheumatology University Hospital from 2009 and 2019 was performed to select those presenting with ADs and MDS or MPNs. To refine the search the ICD-9-CM diagnosis codes for MDS/MPNs were utilized. Medical charts of eligible patients were retrieved and data were collected with regard to demographics, type of AD, AD duration, prior treatments, serum laboratory indices, bone marrow aspiration and biopsy data. Categorical variables were compared using chi square test and Fisher’s test; continuous variables were compared using Student’s t-test. A 2-tailed value of p <0.05 was taken to indicate statistical significance.

Results:

Out of the medical records of 5040 patients, we identified 51 patients (31 F: 20 M, mean age: 61 years (15)) with AD and myeloid malignancies: 17/51 with AD and MDS and 34/51 with AD and MPNs. No demographic differences were observed in the two subgroups. Regarding MDS, anaemia was the most common haematologic presenting finding (15/17, 88%), while the most common diagnosis was refractory anemia with excess of blasts (RAEB I/II) (5/17, 29%) followed by sideroblastic anemia (2/17, 12%). In the MPNs subgroup, 12/34 patients (35%) had a diagnosis of chronic myeloid leukemia (CML), 9/34 (26%) had a myelofibrosis (MF), 7/34 (21%) had an essential thrombocythemia (ET) and 6/34 (18%) had a polycythemia vera (PV). The JAK2 V617F mutation was detected in 100%, 57%, and 66% of PV, ET, and MF patients. Regarding the temporal appearance of myeloid malignancy, MDS occurred concurrently (9/17) or followed (7/17) the diagnosis of ADs in the vast majority of the cases whereas MPNs generally preceded the diagnosis of ADs (19/34). In MDS the most commonly diagnosed ADs were seronegative arthritis (5/17, 29 %), large and small vessel vasculitis (4/17, 23%) and Systemic Lupus Erythematosus (3/17, 17%). In patients with MPNs the diagnosis of rheumatoid arthritis (2/9, 22%), and antiphospholipid syndrome (3/9, 33%) were often associated with MF, whereas anti-Ro52 (TRIM21) positive systemic connective tissue disorders (4/7, 57%) were more frequently detected in ET. Cardiovascular events were observed in 14/51 (27%): 4/17 (23%) in MDS, 3/12 (25%) in CML and 7/22 (32%) in Philadelphia-negative MPNs. The latter seven cardiovascular events were all observed in patients presenting JAK2 V617F mutation (p=0.05).

Conclusion:

Our study is limited by its retrospective design. However, our results documented that the frequency of MDS and MPNs in ADs is not negligible and might be considered in the assessment of cardiovascular risk in systemic autoimmunity. Moreover, it has been reported that, under viral infection, TRIM21 is up-regulated by activation of the IFN/JAK/STAT pathway; interestingly, anti-Ro52 (TRIM21) were over-represented in MPN, where the JAK/STAT signal is hyper activated. This could explain also our observation that frequently the onset of ADs follows the diagnosis of MPN.

Disclosure of Interests:

Francesco Ferro: None declared, Claudia Baratè Speakers bureau: paid as a speaker by Jansen, Abbvie, Novartis, Amgen, Elena Elefante: None declared, Federica Ricci: None declared, Serena Balducci: None declared, Gianmaria Governato: None declared, Giovanni Fulvio: None declared, Marta Mosca: None declared, Mario Petrini Speakers bureau: paid as a speaker by Jansen, Abbvie, Novartis, Amgen, Sara galimberti Speakers bureau: paid as a speaker by Jansen, Abbvie, Novartis, Amgen, Chiara Baldini: None declared

Real-Time PCR and Droplet Digital PCR: two techniques for detection of the JAK2(V617F) mutation in Philadelphia-negative chronic myeloproliferative neoplasms

INTRODUCTION

Philadelphia-negative chronic myeloproliferative neoplasms (MPNs) are clonal disorders that present JAK2(V617F) mutation in 50-95% of cases. The main objective of this study was the comparison of two PCR methods, real-time (qPCR) and droplet digital PCR (DD-PCR) for detection of the JAK2(V617F) mutation, to assess analytic sensitivity, specificity, and feasibility of the two methods.

METHODS

Ninety-nine patients with MPN of 225 presenting the JAK2(V617F) mutation by qPCR have been evaluated by DD-PCR also.

RESULTS

We demonstrated an absolute concordance in terms of specificity between the two methods, DD-PCR showing a higher sensitivity (half a log higher than qPCR). As expected, a progressive increase of mutant allele burden was observed from essential thrombocythemia (ET) to polycythemia vera (PV) and primary myelofibrosis (PMF) to secondary myelofibrosis (SMF).

CONCLUSION

In conclusion, our study showed that DD-PCR could represent a new and promising technological evolution for detection of JAK2 mutation in MPNs.

The c.480C>G polymorphism of hOCT1 influences imatinib clearance in patients affected by chronic myeloid leukemia

The aim of the study was to investigate any possible influence of polymorphisms of transmembrane transporters human organic cation transporter 1 (hOCT1), ABCB1, ABCG2 on imatinib pharmacokinetics in 33 men and 27 women (median age and range, 56 and 27-79 years, respectively) affected by chronic myeloid leukemia. A population pharmacokinetic analysis was performed to investigate imatinib disposition in every patient and the role of transporter polymorphisms. Results showed that the α1-acid glycoprotein and the c.480C>G genotype of hOCT1 had a significant effect on apparent drug clearance (CL/F) being responsible, respectively, for a 20% and 10% decrease in interindividual variability (IIV) of CL/F (from 50.1 up to 19.6%). Interestingly, 25 patients carrying at least one polymorphic c.480 G allele had a significant lower CL/F value with respect to the 35 c.480CC individuals (mean±s.d., 9.6±1.6 vs 12.1±2.3 l h(-1), respectively; P<0.001). In conclusion, the hOCT1 c.480C>G SNP may significantly influence imatinib pharmacokinetics, supporting further analyses in larger groups of patients.