Immune thrombocytopenic purpura in a patient with multiple sclerosis treated with natalizumab

Natalizumab therapy in patients with pediatric-onset multiple sclerosis in Greece: clinical and immunological insights of time-long administration and future directions-a single-center retrospective observational study

Pediatric-onset multiple sclerosis (MS, POMS) accounts for 3-5% of all MS cases and is characterized by a highly inflammatory profile, often warranting treatment with high-efficacy agents. Our aim is to present real-world data of a series of 18 Hellenic POMS patients treated with natalizumab (NTZ) either as adolescents or as adults, after high disease activity has efficiently subsided. Clinical and imaging/laboratory data from 18 POMS patients who have received at least one NTZ infusion were selected in this single-center retrospective observational study. Human leukocyte antigen (HLA) genotyping was performed with standard low-resolution sequence-specific oligonucleotide techniques. Eighteen patients with a mean age of disease onset of 15.3 ± 2.4 years were treated with NTZ with a mean of 51.7 ± 46.4 infusions, 6 as adolescents and 12 as adults. 22.2% were treatment naïve. At the end of the observational period, patients of both groups remained relapse-free, with no radiological activity and significantly reduced disability accumulation. No evidence of disease activity (NEDA)-3 status was achieved in 66.7% of all patients, 58.3% in the adult-treated, and 83.3% in the adolescent-treated POMS patients. NTZ was generally well tolerated. Only 5 adverse events were observed, in 3 patients who were carriers of the HLA-DRB1*15 (HLA-DRB1*15/HLA-DRB1*11 and HLA-DRB1*15/HLA-DRB1*13 genotypes), 1 homozygous for the HLA-DRB1*03 allele and 1 heterozygous for HLA-DRB1*04 and HLA-DRB1*16 alleles. NTZ is highly efficacious and mostly safe for POMS patients with high disease activity in all age groups. The role of immunogenetics in personalized patient evaluation and treatment needs to be further investigated.

Role of antithyroid autoimmunity as a predictive biomarker of chronic immune thrombocytopenia

BACKGROUND

Immune thrombocytopenia (ITP) is an acquired immune-mediated disorder characterized by isolated thrombocytopenia. Pediatric ITP patients are prone to develop autoantibodies such as antithyroglobulin (TG) and antithyroperoxidase (TPO), even in the absence of clinical signs of autoimmune disease. The aim of this multicenter retrospective study was to evaluate (1) the prevalence of positivity of antithyroid antibodies (TPO and TG) in a large cohort of pediatric patients with chronic ITP; (2) the role of autoimmune thyroiditis as a prognostic factor for chronicity of ITP.

PROCEDURE

For this retrospective study, we collected data from patients diagnosed as affected by chronic ITP between 2011 and 2014 in six centers belonging to the Italian Association of Pediatric Haematology and Oncology (AIEOP).

RESULTS

From the analysis of data, we found a significantly higher prevalence of antithyroid antibodies in children with chronic ITP (11.6%) than in the pediatric population (1.2%-1.3%). No correlation has been found between the platelet count and the prevalence of positive antithyroid antibodies at any detection time of the study.

CONCLUSIONS

The results of our study demonstrated that (1) the prevalence of positivity for antithyroid antibodies (anti-TPO and anti-TG) in pediatric patients with chronic ITP results is significantly higher than in the pediatric population; (2) autoimmune thyroiditis does not seem to play a role as a prognostic factor for chronicity of ITP in pediatric patients.

Rescue Therapy Using Rituximab for Multiple Sclerosis

OBJECTIVES

The aim of the study was to describe the effectiveness and safety data of rituximab in a group of patients with relapsing-remitting multiple sclerosis (MS) treated with rituximab due to failure of previous treatments or concomitant autoimmune diseases.

METHODS

This is an observational study. Rituximab was considered in case of failure of the second-line therapy, failure of the first-line therapy and a contraindication to second-line therapies, or concomitant autoimmune disease. Relapses, the Expanded Disability Status Scale, the EQ VAS, and magnetic resonance imaging activity were assessed.

RESULTS

This study included 12 patients with relapsing-remitting MS. The mean (range) age of the patients was 35 (19-54) years. Ten patients were treated with rituximab because of treatment failure, and 2 patients were treated with rituximab because of the development of idiopathic thrombocytopenic purpura. The mean (range) follow-up duration after beginning rituximab was 40 (18-72) months. Rituximab was well tolerated, because no patient experienced serious adverse reactions or discontinued treatment. During treatment with rituximab, no patient suffered a clinical relapse, and magnetic resonance imaging activity was not detected. The Expanded Disability Status Scale scores improved in 11 of 12 patients and remained stable in 1 patient. The EuroQol visual analogue scale scores improved in 8 of 9 patients in whom the EuroQol visual analogue scale was assessed.

CONCLUSIONS

Treatment with rituximab seems to be safe and effective for some patients with relapsing-remitting MS who have failed to respond to first- and second-line therapies and may also be a useful option for patients with concomitant autoimmune disorders.

Drug-induced thrombocytopenia secondary to natalizumab treatment

A 52-year-old woman with a 10-year history of relapsing-remitting multiple sclerosis (RRMS) was started on natalizumab after she developed side effects for interferon β-1a and glatiramer acetate. The patient presented with acute severe infusion reaction after the third treatment with natalizumab, developing whole-body purpura. Laboratory testing revealed progressive worsening thrombocytopenia up to 3 weeks following natalizumab discontinuation. Platelet antibodies to platelet-specific antigen as well as antibodies against natalizumab were positive. Bone marrow biopsy was negative. The patient was diagnosed with drug-induced immune thrombocytopenia (DITP) as a rare case of natalizumab side effect which was treated with intravenous methylprednisolone followed by rituximab with successful resolution of thrombocytopenia. The patient had a stable course of RRMS with no relapses and no brain MRI changes at 2 years after initiation of rituximab.

Severe haematological complications during treatment with natalizumab

The safety profile of natalizumab has been widely discussed due to several cases of progressive multifocal leukoencephalopathy, reported worldwide. Since the launch of natalizumab, 32 patients have been treated at our centre. In this context, we describe two cases (6.25%), one of immune-mediated acute haemolytic anaemia (IAHA) and another of immune thrombocytopenic purpura during treatment with natalizumab. The temporal relationship between drug administration and the nature of the haematological complications, confirmed with the serological findings in the case of the IAHA, suggests that natalizumab is the most probable cause for these adverse events. Although very uncommon, the haematological complications are severe enough to justify a close and careful monitoring for all patients with multiple sclerosis treated with an immunosuppressant treatment.

A distinctive form of immune thrombocytopenia in a phase 2 study of alemtuzumab for the treatment of relapsing-remitting multiple sclerosis

In a phase 2 clinical trial of annual alemtuzumab for treatment of relapsing-remitting multiple sclerosis, 6 of 216 patients (2.8%) developed immune thrombocytopenia (ITP). Over mean follow-up of 4.5 years, the incidence rate of ITP was 6.2 (95% confidence interval, 2.3-13.3) per 1000 person-years. Median times from initial and last alemtuzumab exposure to ITP diagnosis were 24.5 and 10.5 months, respectively. Five patients developed severe thrombocytopenia. Four were symptomatic, including fatal intracranial hemorrhage in the index case. Four patients received standard first-line ITP therapy, all of whom responded to treatment within 1 week. All 5 surviving patients achieved complete remission and remained in complete remission without need for ongoing ITP therapy for a median duration of 34 months at last follow-up. A monitoring plan for the early detection of ITP, implemented after presentation of the index case, identified all 5 subsequent cases before serious hemorrhagic morbidity or mortality occurred. In conclusion, we describe a distinctive form of ITP associated with alemtuzumab treatment characterized by delayed presentation after drug exposure, responsiveness to conventional ITP therapies, and prolonged remission. Clinicians should maintain a high level of vigilance and consider routine monitoring for ITP in patients treated with this agent. This trial was registered at www.clinicaltrials.gov as #NCT00050778.