Hematological and Genetic Markers in the Rational Approach to Patients With HCV Sustained Virological Response With or Without Persisting Cryoglobulinemic Vasculitis

Abstract

Background and aims: Direct-acting antivirals (DAAs) usually lead to improvement/remission of cryoglobulinemic vasculitis (CV), although symptoms may persist/recur after a sustained virological response (SVR). We evaluated hematological and genetic markers in patients with HCV-SVR vasculitis with and without persisting/recurring symptoms to early predict the CV outcome.

Approach and results: Ninety-eight patients with HCV-CV were prospectively enrolled after a DAA-induced SVR: Group A: 52 with complete clinical response; Group B: 46 with symptom maintenance/recurrence. Monoclonal B-cell lymphocytosis, t(14;18) translocation, and abnormal free light chains κ/λ ratios were detected by flow cytometry or nested-PCR or nephelometry in 4% Group A versus 17% Group B (P = 0.04) patients, 17% Group A versus 40% Group B patients (P = 0.02), and 17% Group A versus 47% Group B (P = 0.003) patients, respectively. At least 1 out of 3 clonality markers was altered/positive in 29% of Group A versus 70% of Group B patients (P < 0.0001). When available, pretherapy samples were also tested for t(14;18) translocation (detected in 12/37 [32%] Group A and 21/38 [55%] Group B) and κ/λ ratios (abnormal in 5/35 [14%] Group A and 20/38 [53%] Group B) (P = 0.0006), whereas at least one clonality marker was detected/altered in 16/37 (43%) Group A and 30/38 (79%) Group B (P = 0.002). CV-associated single-nucleotide polymorphisms were tested by real-time PCR. Among them, notch4 rs2071286 T minor allele and TT genotype showed a higher frequency in Group B versus Group A (46% vs. 29%, P = 0.01, and 17% vs. 2%, P = 0.006, respectively).

Conclusions: Hematological or genetic analyses could be used to foresee the CV clinical response after DAA therapy and could be valuable to assess a rational flowchart to manage CV during follow-up.

FIG. 1

Results of clonality marker analysis at the end of posttherapy follow‐up. On the y axis, data are expressed as percentage. (A) Presence of MBL (B‐cell surface κ/λ ratio) in Group A and Group B patients (4% vs. 17%, P = 0.04; Relative Risk (RR), 2.841; 95% CI, 0.8116‐9.945). (B) Presence of t(14;18) in Group A and Group B patients (17% vs. 40%, P = 0.02; RR, 1.900; 95% CI, 1.030‐3.503). (C) Alteration of serum FLC κ/λ ratio in Group A and Group B patients (16% vs. 46%, P = 0.003; RR, 2.222; 95% CI, 1.202‐4.110). (D) Presence of at least one clonality marker in Group A and Group B patients (29% vs. 70%, P < 0.0001; RR, 2.273; 95% CI, 1.494‐3.649).

FIG. 2

Results of the clonality marker analysis in pretherapy available samples. On the y axis, data are expressed as percentage. (A) Presence of t(14;18) in Group A and Group B patients (32% vs. 55%). (B) Alteration of serum FLC κ/λ ratio in Group A and Group B patients (14% vs. 53%, P = 0.0006; OR, 6.667; 95% CI, 2.130‐20.87). (C) Presence of at least one clonality marker in Group A and Group B patients (43% vs. 79%, P = 0.002; OR, 4.922; 95% CI, 1.830‐13.76).

FIG. 3

Results of the genotyping analysis of HLA class II rs9461776 and Notch4 rs2071286. On the y axis, data are expressed as percentage. (A) Distribution of polymorphic variant of the HLA class II rs9461776. A/G was present in 31% Group A vs. 56% Group B, and G minor allele was present in 22% Group A and 33% Group B. The homozygous minor genotype G/G was present in 6% Group A vs. 4% Group B. (B) Distribution of polymorphic variant of the Notch4 rs2071286. Homozygous haplotype T/T: 2% Group A vs. 16% Group B; P = 0.006. T minor allele frequency: 29% Group A vs. 47% Group B (P = 0.01; OR, 2.17; 95% CI, 1.18‐3.9).