Discussion
After AHSCT for RRMS, CSF concentrations of CXCL13 were rapidly normalized, whereas sCD27 decreased gradually over the course of 2 years. Thereafter, the concentrations remained stable throughout follow-up, indicating that AHSCT induced long-lasting biological changes.
Methods
This prospective cohort study was conducted at a specialized MS clinic in a university hospital. Patients with a diagnosis of RRMS, treated with AHSCT between January 1, 2011, and December 31, 2018, were evaluated for participation. Patients were included if CSF samples from baseline plus at least 1 follow-up were available on June 30, 2020. A control group of volunteers without neurologic disease was included as a reference. CSF concentrations of CXCL13 and sCD27 were measured with ELISA.
Results
The study comprised 29 women and 16 men with RRMS, aged 19-46 years at baseline, and 15 women and 17 men, aged 18-48 years, in the control group. At baseline, patients had higher CXCL13 and sCD27 concentrations than controls, with a median (IQR) of 4 (4-19) vs 4 (4-4) pg/mL (p < 0.0001) for CXCL13 and 352 (118-530) vs 63 (63-63) pg/mL (p < 0.0001) for sCD27. After AHSCT, the CSF concentrations of CXCL13 were considerably lower at the first follow-up at 1 year than at baseline, with a median (IQR) of 4 (4-4) vs 4 (4-19) pg/mL (p < 0.0001), and then stable throughout follow-up. The CSF concentrations of sCD27 were also lower at 1 year than at baseline, with a median (IQR) of 143 (63-269) vs 354 (114-536) pg/mL (p < 0.0001). Thereafter, sCD27 concentrations continued to decrease and were lower at 2 years than at 1 year, with a median (IQR) of 120 (63-231) vs 183 (63-290) pg/mL (p = 0.017).