Hydroxychloroquine is a good second‐line treatment for adults with immune thrombocytopenia and positive antinuclear antibodies

Treatment of patients with lupus‐associated thrombocytopenia (SLE‐ITP) is not standardized. We report data on efficacy and safety of hydroxychloroquine (HCQ) in this setting and in ITP patients with positive antinuclear antibodies (ANA) without definite SLE. Inclusion criteria were: definite diagnosis of ITP with a platelet count (PLT) <50 × 10⁹/L, ANA ≥ 1/160 on Hep2 cells with or without a definite diagnosis of SLE, and no sustained response to at least one previous treatment‐line and treatment with HCQ. Response criteria were Complete Response (CR) for PLT ≥ 100 × 10⁹/L and Response (R) for PLT ≥30 × 10⁹/L and at least twice the initial value. Forty patients (32 females) with a mean age of 35 ± 17 years and PLT at ITP diagnosis of 14 ± 13 × 10⁹/L were analyzed. Twelve (30%) patients had a SLE‐ITP, 28 patients had only positive ANA. All the patients failed to respond to oral prednisone with a median of two treatment‐lines (1–5) before HCQ which was initially given in combination with another ITP treatment in 36 patients. Overall response rate was 60% (24/40) including 18 lasting CR and six lasting R maintained with a median follow‐up of 64 months (6–146), in ¾ of cases with only HCQ and no concomitant ITP treatment. The response rate (CR+R) was higher in the SLE group vs ANA‐positive group (83% vs 50%, P < 0.05). No patient stopped HCQ because of a side‐effect. HCQ appears to be a safe and effective second line treatment for patients with SLE‐ITP or ITP and high titer of ANA. This trial was registered at www.clinicaltrials.gov as # NCT01549184. Am. J. Hematol. 89:194–198, 2014. © 2013 Wiley Periodicals, Inc.