Objective:

This study aims to investigate the immunological features and differences of B cells during the acute phase of Anti-NMDAR encephalitis in bone marrow, peripheral blood, and cerebrospinal fluid (CSF) to explore the underlying pathogenic mechanisms.

Background:

Anti-N-methyl-D-aspartate receptor (NMDAR) encephalitis is a severe autoimmune disorder characterized by a complex interplay of immune cells.

Design/Methods:

We collected bone marrow, peripheral blood, and cerebrospinal fluid (CSF) samples from patients diagnosed with Anti-NMDAR encephalitis. From these samples, we prepared single-cell suspensions and performed single-cell RNA sequencing to analyze the transcriptional profiles of individual cells. We then conducted differential expression analysis to compare the transcriptional profiles of the patient samples with those of the controls, using data from a public database as the reference for the control group.

Results:

In acute-phase bone marrow of anti-NMDAR encephalitis patients, there's a notable drop in IgM and IgG memory B cells, DN cells, pre-B cells, and progenitors, but an increase in anergic and naive B cells, compared to normals.

Blood comparisons show elevated IgG and IgM memory B cells, DN cells, and progenitors in acute-phase patients versus normals.

In CSF, acute-phase patients show increased IgG and IgM, memory B cells, DN cells, and anergic B cells, with fewer pre-B cells, compared to normals.

The results of cell communication analysis indicate that both bone marrow and cerebrospinal fluid are enriched with genes related to immunoglobulin production and antigen binding, involving proton transport and ATP synthesis. In peripheral blood, genes related to energy metabolism are enriched.

Conclusions:

In patients with anti-NMDAR encephalitis during the acute phase, the immune cell activity in various bodily fluids is significantly increased compared to normal individuals.