A Toolkit for Monitoring Immunoglobulin G Levels from Dried Blood Spots of Patients with Primary Immunodeficiencies.

PURPOSE: This study assessed whether measuring immunoglobulin G (IgG) from dried blood spots (DBSs) using nephelometry is a suitable remote monitoring method for patients with primary immunodeficiencies (PID). METHODS: Patients receiving immunoglobulin replacement therapy for PID were included in this non-interventional single-arm study (DRKS-ID: DRKS00020522) conducted in Germany from December 4, 2019, to December 22, 2020. Three blood samples, two capillary DBSs (one mail-transferred and the other direct-transferred to the laboratory), and one intravenous were collected from each patient. IgG levels were determined using nephelometry. IgG levels were summarized descriptively, and significant differences were assessed using Wilcoxon matched-pairs signed-rank tests. Correlation and agreement between IgG levels were assessed using Spearman correlation and Bland-Altman analyses, respectively. RESULTS: Among 135 included patients, IgG levels measured from DBS samples were lower than those measured in serum (p < 0.0001). There was no significant difference between IgG levels in direct- and mail-transferred DBS samples. There was a high degree of correlation between IgG levels in serum samples and DBS samples (r = 0.94-0.95). Although there was a bias for higher levels of IgG in serum than in DBS samples, most samples were within the 95% interval of agreement. There was a high degree of correlation between IgG levels measured in direct- and mail-transferred DBS samples (r = 0.96) with no bias based on the shipment process and most samples within the 95% interval of agreement. CONCLUSION: Monitoring IgG levels from DBS samples is a suitable alternative to the standard method, and results are not substantially affected by mailing DBS cards.

Treatment de-escalation after mitoxantrone therapy: results of a phase IV, multicentre, open-label, randomized study of subcutaneous interferon beta-1a in patients with relapsing multiple sclerosis.

OBJECTIVE: The objective of this study was to assess the effect of treatment with interferon (IFN) ß-1a, 44 µg subcutaneously (sc) three times weekly (tiw), on clinical and magnetic resonance imaging (MRI) outcomes in patients with relapsing multiple sclerosis (MS) following mitoxantrone therapy. METHODS: This was an open-label, randomized, multicentre, rater-blinded, 96-week observational study conducted in Germany. Clinically stable patients with relapsing forms of MS, who had discontinued mitoxantrone treatment 1-6 months before study entry, were randomized to IFN ß-1a sc 44 µg tiw, or no treatment. The primary endpoint was time to first relapse. Secondary endpoints included the number of relapse-free patients, disease activity assessed by MRI and time to 3-month confirmed Expanded Disability Status Scale (EDSS) progression, all at week 96. RESULTS: A total of 30 patients were randomized (intent-to-treat population: 14 IFN ß-1a, 15 untreated; one patient from the safety population discontinued the study after 25 days owing to an adverse event and without providing any postbaseline efficacy data, and was thus excluded from the intent-to-treat population). Overall, 71.4% (10/14) of patients in the IFN ß-1a group remained relapse free over 96 weeks, versus 46.7% (7/15) in the untreated group (p = 0.26). IFN ß-1a delayed the time to first relapse versus no treatment (p = 0.14); time to first relapse (25th percentile) was 95.4 (IFN ß-1a) versus 46.0 weeks (no treatment). Confirmed EDSS progression was observed in five patients in each treatment group. Mean change in EDSS score was 0.3 in both groups (p = 0.79). Changes in the number or volume of T1 and T2 lesions at week 96 were not significantly different between treatment groups (p > 0.05). There were no new or unexpected adverse events related to IFN ß-1a treatment. CONCLUSIONS: Several endpoints appeared to show a benefit of IFN ß-1a treatment, but no significant differences could be detected owing to the small sample. Therefore, these data only permit, at best, tentative conclusions about the disease course in patients with MS after de-escalation from mitoxantrone and continuation with or without IFN ß-1a. Larger confirmatory studies are required.