Comparison of outcomes using the rituximab originator MabThera with the biosimilar Truxima in patients with ANCA-associated vasculitis.

OBJECTIVES: The use of rituximab (MabThera®), an anti-CD20 monoclonal antibody, is the most significant development in the management of anti-neutrophil cytoplasm antibody (ANCA)-associated vasculitis (AAV) since the introduction of cytotoxic therapy in 1950. Truxima® is the first anti-CD20 biosimilar approved for the same indications, and has been available in the UK since 2017. Significant cost savings have been reported when switching to biosimilars, which could lead to greater patient access to such treatment. Therefore, it is important to know whether patients' clinical and laboratory parameters respond equally well to biosimilars as to reference medicines, tested in clinical trials. METHOD: We retrospectively reviewed the clinical outcomes and laboratory parameters in 257 consecutive patients treated with anti-CD20 depletion therapy using MabThera or Truxima, for induction and maintenance of remission, in two tertiary renal centres between 2010 and 2019. RESULTS: We demonstrated no difference between patients treated with MabThera or Truxima in rates of remission, relapse, and hospitalization with infection when used for either induction or maintenance of remission of AAV. In one hospital subgroup analysis, we showed comparable levels of hypogammaglobulinaemia, B-cell depletion, and frequency of infusion reactions, with no significant differences. CONCLUSION: The efficacy and safety of the rituximab biosimilar Truxima are not inferior to the originator MabThera in patients with AAV. Truxima represents a cheaper and safe therapeutic alternative that could increase patient access to rituximab.

Changes in serum osmotic pressure following haemodialysis treatments lead to changes in bioimpedance spectroscopy estimates of lean and adipose tissue.

Haemodialysis (HD) patients are at risk of sarcopenia. Newer bioimpedance devices (BIS) using a three-compartmental body composition model, separate extracellular water overhydration from normo-hydrated lean tissue mass (LTM) and adipose tissue mass (ATM). During HD hydration status changes, along with changes in electrolytes and solutes, and may alter body composition measurements. As such, we measured BIS and serum osmotic pressure (sOP) pre- and post dialysis in 43 patients. There were no significant changes in LTM (39.5±15.1 vs 39.3±15.2 kg) or sOP (33.2±8.3 vs 35.9±9.7 mm Hg). Higher post-dialysis sOP was associated with a greater percentage fall in LTM (r=0.43, P=0.08) and increase in ATM (r=-0.43, P=0.017). Increased sOP post dialysis was associated with a reduction in LTM (r=0.36, P=0.033) and increased ATM (r=-0.44, P=0.013). Changes in sOP with HD are associated with changes in BIS body composition measurements. BIS measurements should preferably be made when patients are least overhydrated.

A novel case of haemoglobin H disease associated with clinical and morphological characteristics of congenital dyserythropoietic anaemia type I.

We report, for the first time, an unusual case of congenital anaemia with the clinical diagnosis of haemoglobin H disease complicated by morphological features at the light and electron microscopy level very similar to those of CDA-I. The red cell indices and the globin chain biosynthetic ratio were not characteristic of the defective haemoglobin genotype. The haematological, clinical and morphological data strongly suggest the novel coexistence of the two defects in a patient. The disease is characterised by a unique dyserythropoietic phenotype of diagnostic importance, which possibly brings new data regarding the reciprocal interaction between the two diseases, especially concerning a specific abnormality in globin chain synthesis in CDA-I, as previously suggested.