Correlation of Symptom Assessment with Genotyping Analysis of Saliva Samples in a Large Cohort of Myeloproliferative Neoplasm Patients

In addition to chronic myelogenous leukemia (CML), the classic myeloproliferative neoplasms (MPNs) include polycythemia vera (PV), essential thrombocythemia (ET), and primary myelofibrosis (PMF). The JAK2 V617F mutation (V617F) can be detected through genomic analysis of peripheral blood in 95% of PV and 50–60% of ET and MF patients (pts). These MPNs are often associated with debilitating symptoms and decreased quality of life (QOL). Systemic mastocytosis (SM) is an uncommon MPN in which proliferation of mast cells can result in mediator symptoms, as well as organ damage in advanced disease. We sought to compare the symptom burden of individuals with CML and SM to pts with classic MPNs in a more quantitative manner using a web-based recruitment design.

Individuals with MPN were recruited through a web-based outreach effort. Participants gave IRB-approved consent, and completed on-line surveys of demographic information and questions based on the validated MPN-symptom assessment form (MPN-SAF). In addition, pts submitted saliva samples which were genotyped with SNP arrays based on the Illumina OmniExpress BeadChip, including probes for V617F. Regression analysis was used to evaluate the correlation between symptom responses and genotype data for 495 pts (118 PV, 121 ET, 97 MF, 85 SM, and 74 CML). For each MPN diagnosis, mean scores were calculated based on six fatigue-focused questions (Fatigue-6) and for six other symptoms (Symptom-6): early satiety, abdominal pain/discomfort, inactivity, night sweats, pruritis, and bone pain (ranked from 0–10; 10 = worst). ET pts' scores were used as the reference in the regression analysis based on prior data showing that ET pts have the lowest symptom burden among the classic MPNs. Individual symptoms, Fatigue-6, Symptom-6, and QOL (ranked 0–10; 10=worst) were analyzed using regression analysis against age, gender, diagnosis and V617F status.

Median age was 56 years (7–87), with 70% women. V617F was detected in 63% of classic MPN pts (87% PV, 46% ET, 56% MF). Analysis of Fatigue-6 scores revealed that age in years was negatively correlated with reported fatigue (β=-0.007 per year, P=0.032), while female gender and SM diagnosis were positively correlated with fatigue (female: β=0.33, P=2.4×10⁻⁴; SM: β=0.46, P=7.6×10⁻⁴). This trend was also seen for the Symptom-6: age (β=-0.025, P=5.8×10⁻⁴), female gender (β=0.73, P=1.4×10⁻⁴), and SM (β=1.8, P=5.0×10⁻¹⁰). Both Fatigue-6 and Symptom-6 were positively correlated with QOL, but Fatigue-6 had a much stronger association with QOL than did Symptom-6 (β=1.3, P=1.5×10⁻²⁸ vs. β=0.36, P=1.2×10⁻¹¹). When analyzed individually, abdominal pain/discomfort, pruritis, and bone pain were significantly correlated with V617F (β=0.676, P=0.0371; β=0.768, P=0.0241; β=0.791, P=0.0341, respectively), though these associations were not significant when all six symptoms were evaluated together (Symptom-6: β=0.315, P=0.171). There was no statistically significant correlation between V617F and Symptom-6. In addition, there was no correlation between any symptom and a germline variant in telomerase reverse transcriptase (TERT) rs2853677, identified as a novel predisposition allele for MPNs using a genome-wide association study of this cohort.

Using a novel, web-based recruitment design combining MPN symptom assessment and genotyping of saliva samples, we identified significant correlations between 3 specific symptoms (pruritis, abdominal pain/discomfort, and bone pain) with V617F. Fatigue was also more strongly associated than other symptoms with QOL. There was no association between symptoms and TERT. This design is a powerful tool for future studies seeking to correlate symptoms with genotyping analysis.

Hinds:23andMe: Employment, Equity Ownership, Patents & Royalties. Barnholt:23andMe, Inc.: Employment. Kiefer:23andMe, Inc.: Employment. Do:23andMe, Inc.: Employment, Equity Ownership, Patents & Royalties. Eriksson:23andMe, Inc.: Employment, Equity Ownership, Patents & Royalties. Mountain:23andMe, Inc.: Consultancy, Employment, Honoraria, Patents & Royalties, Research Funding. Francke:23andMe, Inc.: Employment, Honoraria, Research Funding; Locus Development: Consultancy, Membership on an entity's Board of Directors or advisory committees. Tung:23andMe, Inc.: Employment. Zehnder:23andMe, Inc.: Unpaid advisor and collaborator Other. Gotlib:23andMe, Inc.: Unpaid advisor and collaborator Other. Mesa:23andMe, Inc: Unpaid advisor and collaborator Other.