A Lower Proportion of Regulatory B Cells in Patients with Henoch-Schoenlein Purpura Nephritis

Application of CD38 monoclonal antibody in kidney disease

CD38 antigen is a glycoprotein that found on the surface of several immune cells, and this property makes its monoclonal antibodies have the effect of targeted elimination of immune cells. Therefore, the CD38 monoclonal antibody (such as daratumumab, Isatuximab) becomes a new treatment option for membranous nephropathy, lupus nephritis, renal transplantation, and other refractory kidney diseases. This review summarizes the application of CD38 monoclonal antibodies in different kidney diseases and highlights future prospects.

Regulatory T and B cells in pediatric Henoch-Schönlein purpura: friends or foes?

BACKGROUND AND OBJECTIVES

Henoch-Schönlein purpura (HSP) is the most common immunoglobulin A-mediated systemic vasculitis in childhood. We studied immune dysregulation in HSP by analyzing regulatory T (Treg), T helper 3 (Th3), and regulatory B cell (Breg) subpopulations that might intervene in immune activation, IgA production, and HSP clinical manifestations.

METHODS

This prospective study included 3 groups of children: 30 HSP on acute phase, 30 HSP on remission, and 40 healthy controls (HCs) matched on age. Treg, Breg, and Th3 were analyzed by flow cytometry. Serum immunoglobulin and cytokine levels were quantified by ELISA and Luminex.

RESULTS

Treg frequencies were higher in acute HSP than in remitting HSP and HCs (6.53% [4.24; 9.21] vs. 4.33% [3.6; 5.66], p = 0.002, and vs. 4.45% [3.01; 6.6], p = 0.003, respectively). Activated Th3 cells (FoxP3 + Th3 cells) tend to be more abundant in HSP than in HCs (78.43% [50.62; 80.84] vs. 43.30% [40.20; 49.32], p = 0.135). Serum IgA, IL-17, and latency-associated peptide (a marker of the anti-inflammatory cytokine TGF-beta production) were significantly and inflammatory cytokines TNF-alpha, IL-1-beta, and IL-6 were non-significantly higher in HSP than HCs. Bregs were identical between the groups, but, in patients with renal impairment, Breg percentage was lower compared to those without. Treg removal in PBMC culture resulted in an increase in IgA production in HSP proving a negative regulatory role of Tregs on IgA production.

CONCLUSIONS

In pediatric HSP, immune activation persists in spite of an increase in Th3 and Tregs. Th3 could be involved in IgA hyperproduction, inefficiently downregulated by Tregs. Lack of Bregs appears linked to renal impairment.

Distribution characteristics of circulating B cell subpopulations in patients with chronic kidney disease

This study compared the levels of circulating B cell subpopulations in patients with different stages of chronic kidney disease (CKD), investigated the effects of haemodialysis (HD) on the B cell-related immune spectrum in patients with end-stage renal disease, and evaluated the link between renal function and immune homeostasis. Overall, 197 patients with CKD (158 non-dialysis patients with CKD stages I-V and 39 end-stage patients undergoing maintenance HD) and 77 healthy controls were included. Compared to healthy controls, patients with CKD stages I-II showed no significant differences except for the proportion of transitional B cells; patients with CKD stage V showed a significant decrease in the proportions of transitional B cells and CD5+ B cells and a significant increase in double-negative (DN) B cells. Compared with early-stage patients with CKD, the absolute count of various B cell subpopulations in advanced-stage patients with CKD showed a significant decrease. The distribution of circulating B cell subpopulations in patients with CKD was significantly altered and was associated with CKD progression. Furthermore, the proportion of DN B cells and CD5+ B cells was inconsistent pre- and post-HD. This in-depth study of the immune status of patients with CKD may have important clinical value.

Regulatory B Cell Therapy in Kidney Transplantation

In the context of kidney injury, the role of Bregs is gaining interest. In a number of autoimmune diseases, the number and/or the function of Bregs has been shown to be impaired or downregulated, therefore restoring their balance might be a potential therapeutic tool. Moreover, in the context of kidney transplantation their upregulation has been linked to tolerance. However, a specific marker or set of markers that define Bregs as a unique cell subset has not been found and otherwise multiple phenotypes of Bregs have been studied. A quest on the proper markers and induction mechanisms is now the goal of many researchers. Here we summarize the most recent evidence on the role of Bregs in kidney disease by describing the relevance of in vitro and in vivo Bregs induction as well as the potential use of Bregs as cell therapy agents in kidney transplantation.

Altered B cell compartment associated with Tfh cells in children with Henoch-Schonlein Purpura

AIM

IgA-producing B cells have been found to be associated with children diagnosed with Henoch-Schonlein purpura (HSP). The aim of the present study was to determine whether children with HSP possess altered B-cell subsets.

METHODS

A total of 14 children diagnosed with HSP and age- and sex-matched healthy controls (HCs) were enrolled in our study. Peripheral blood mononuclear cells were isolated, and the percentage and absolute number of B-cell subsets and Follicular helper T (Tfh) cells were determined by flow cytometry. Finally, Spearman's correlation coefficient was used to analyse the correlation between the percentage of Tfh cells and B-cell subsets.

RESULTS

We found that compared to HCs, the frequency and absolute number of total B cells were significantly higher in children with HSP, but the percentages of plasma cells and naïve B cells were significantly lower. A significantly increased percentage and absolute number of memory nonswitched B cells were found in children with HSP compared with HCs. We observed that the expression of C-X-C chemokine receptor type 5 (CXCR5) on total CD4⁺ T cells and the percentage of CD4⁺CXCR5⁺ cells were significantly increased in patients with HSP. Moreover, significantly correlations between Tfh cells and various B-cell subsets were observed.

CONCLUSIONS

Our study showed a Tfh-cell-associated altered B cell compartment in children with HSP.

The Role of Regulatory B cells in Kidney Diseases

B cells, commonly regarded as proinflammatory antibody-producing cells, are detrimental to individuals with autoimmune diseases. However, in recent years, several studies have shown that regulatory B (Breg) cells, an immunosuppressive subset of B cells, may exert protective effects against autoimmune diseases by secretion of inhibitory cytokines such as IL-10. In practice, Breg cells are identified by their production of immune-regulatory cytokines, such as IL-10, TGF-β, and IL-35, however, no specific marker or Breg cell-specific transcription factor has been identified. Multiple phenotypes of Breg cells have been found, whose functions vary according to their phenotype. This review summarizes the discovery, phenotypes, development, and function of Breg cells and highlights their potential therapeutic value in kidney diseases.

Effects of dexamethasone and gamma globulin combined with prednisone on the therapeutic effect and immune function of Henoch-Schonlein purpura nephritis in children

Background

Henoch‐Schonlein purpura nephritis (HSPN) is a serious complication of Henoch‐Schonlein purpura (HSP), which is usually treated with immunosuppressant and glucocorticoid. This study was designed to explore the effect of dexamethasone and gamma globulin combined with prednisone in the treatment of pediatric HSPN.

Methods

According to the treatment plan, 60 children treated with dexamethasone and gamma globulin were included in the control group, and the rest 55 children treated with dexamethasone and gamma globulin combined with prednisone were selected as the research group. The clinical manifestations, therapeutic effect, immune function, serum inflammatory factors, blood coagulation function, urine routine, renal function, and adverse reactions were compared between the two groups.

Results

The clinical manifestations of children in the research group were significantly better than those in the control group after treatment (P < .05). The total effective rate in the research group (94.55%) was markedly higher than that in the control group (76.67%) (P < .05). CD3+, CD4+, CD8+, IL‐10, PT, and APTT increased while CD4+/CD8+, IgA, IL‐8, TNF‐α, FIB, urine protein, urine red blood cell, Scr, and BUN decreased in both groups after treatment, and the changes of all the above indexes in the research group were significant than those in the control group (P < .05). The incidence of adverse reactions in the research group was remarkably superior to that in the control group (P < .05).

Conclusion

Dexamethasone and gamma globulin combined with prednisone can improve the immune function of children with HSPN and promote the recovery of renal function.

Effect of Montmorillonite powder on intestinal mucosal barrier in children with abdominal Henoch-Schonlein purpura: A randomized controlled study

BACKGROUND

Our previous studies found that intestinal barrier function has been changed in children with abdominal Henoch-Schonlein purpura (HSP). Montmorillonite has been shown to be protective for digestive tract mucosa.

OBJECTIVE

The present study aimed to investigate whether Montmorillonite powder could improve the intestinal mucosal barrier function in children with abdominal HSP.

METHODS

Using a randomized controlled study design, we compared plasma levels of diamine oxidase (DAO), D-lactate, and endotoxin in children with abdominal HSP before and after Montmorillonite powder treatment.

RESULTS

Among 28 patients in experimental group and 30 in control group, there was no significant difference in age, sex, height, weight, and course of disease between 2 groups (P > .05). Before treatment, there was no statistical difference in DAO, D-lactic acid, and endotoxin between experimental group and the control group (P > .05). However, significant differences were detected for DAO and D-lactate after treatment in comparison to before treatment in the Montmorillonite experimental group (P < .05). Such differences were not found in the control group (P > .05).

CONCLUSION

Montmorillonite powder is effective in the treatment of HSP via maintaining intestinal mucosal barrier function.

Regulatory B cells: the cutting edge of immune tolerance in kidney transplantation

Kidney transplantation is the optimal treatment for end-stage renal diseases. Although great improvement has been achieved, immune tolerance is still the Holy Grail that every organ transplant practitioner pursues. The role of B cells in transplantation has long been considered simply to serve as precursors of plasma cells, which produce alloantibodies and induce antibody-mediated rejection. Recent research indicates that a specialized subset of B cells plays an important role in immune regulation, which has been well demonstrated in autoimmune diseases, infections, and cancers. This category of regulatory B cells (Bregs) differs from conventional B cells, and they may help develop a novel immunomodulatory therapeutic strategy to achieve immune tolerance in transplantation. Here, we review the latest evidence regarding phenotypes, functions, and effectors of Bregs and discuss their diverse effects on kidney transplantation.

[Research advances in immunological pathogenesis of immunoglobulin A vasculitis]

Immunoglobulin A (IgA) vasculitis is the most common leukocytoclastic small-vessel vasculitis in children and mainly involves the small vessels in the skin, joints, digestive tract, and kidneys. Its pathogenesis is still unclear. Currently, it is believed that environmental factors can cause autoimmune dysfunction and lead to the deposition of IgA-containing immune complexes on the wall of arterioles on the basis of genetic factors. This article reviews the research advances in the role of immune factors in the pathogenesis of IgA vasculitis.

[Research advances in immunological pathogenesis of immunoglobulin A vasculitis]

Immunoglobulin A (IgA) vasculitis is the most common leukocytoclastic small-vessel vasculitis in children and mainly involves the small vessels in the skin, joints, digestive tract, and kidneys. Its pathogenesis is still unclear. Currently, it is believed that environmental factors can cause autoimmune dysfunction and lead to the deposition of IgA-containing immune complexes on the wall of arterioles on the basis of genetic factors. This article reviews the research advances in the role of immune factors in the pathogenesis of IgA vasculitis.

Regulatory B cells in autoimmune rheumatic diseases

Background:

Regulatory B cells (regulatory B cells, Breg cells) in recent years have been shown to be important immunoregulatory factors.

Aim:

To review the role of Breg cells in autoimmune rheumatic diseases.

Methods:

This descriptional review was carried out after research on PubMed using the keywords “Bregs and rheumatoid arthritis”, “systemic lupus erythematosus”, “Sjögren’s syndrome”, “systemic sclerosis”, “vasculitis”, and “dermatomyositis”.

Results:

Breg cells have an inhibitory effect on pro-inflammatory Th1 and Th17 cells and prevent the development of autoimmune diseases. Breg cells mediate their effects through interleukin-10 (IL-10, IL-10+Breg cells), but recently other Breg cells have been recognized that mediate their effects through IL-35 (IL-35+Breg cells), or through transforming growth factor-β (TGFβ, TGFβ+Breg cells). In experimental models of autoimmune diseases, Breg cells are decreased, and when expanded ex vivo and re-infused back into animals, they ameliorate disease. In humans, IL-10+Breg cells are decreased in active autoimmune diseases, such as rheumatoid arthritis, ANCA-associated vasculitis, and systemic sclerosis, and may increase to normal levels in disease remission.

Conclusions:

The deficiency of IL-10+Breg cells during active autoimmune rheumatic disease suggests that Breg cells may be used as biomarkers and be a possible therapeutic target in these diseases.

B cell regulation of the anti-tumor response and role in carcinogenesis

The balance between immune effector cells such as T cells and natural killer cells, and immunosuppressive Treg cells, dendritic, myeloid and monocytic sub-populations in the tumor microenvironment acts to calibrate the immune response to malignant cells. Accumulating evidence is pointing to a role for B cells in modulating the immune response to both solid tumors and hematologic cancer. Evidence from murine autoimmune models has defined B regulatory cell (Breg) subsets that express cytokines such as IL-10, TGF-β, and/or express immune regulatory ligands such as PD-L1, which can suppress T cell and/or natural killer cell responses. Multiple murine tumor models exhibit decreased tumor growth in B cell deficient or B cell depleted mice. In several of these models, B cells inhibit T cell mediated tumor immunity and/or facilitate conversion of T cells to CD4⁺CD25⁺FoxP3⁺ T regs, which act to attenuate the innate and/or adaptive antitumor immune response.

Mechanisms of suppression include the acquisition of inhibitory ligand expression, and phosphorylation of Stat3, and induction of IL-10 and TGF-β, resulting in a Breg phenotype. Breg suppressive activity may affect diverse cell subtypes, including T effector cells, NK cells, myeloid derived suppressor cells (MDSC) and/or tumor associated macrophages. B cells may also directly promote tumorigenesis through recruitment of inflammatory cells, and upregulation of pro-angiogenic genes and pro-metastatic collagenases.

Breg infiltration has now been identified in a variety of solid tumor malignancies including but not limited to ovarian, gastric, non-small cell lung cancer, pancreatic, esophageal, head and neck, and hepatocellular carcinomas. Increasing evidence suggests that recruitment of B cells and acquisition of suppressive activity within the tumor bed may be an important mechanism through which B cells may modulate innate and/or adaptive anti-tumor immunity. B cell depletion in the clinic using anti-CD20 antibodies and/or inhibitors of BTK and/or other signaling pathways, may be a useful strategy for augmenting the anti-tumor immune response.