Histopathological and immunological changes during the acute and recovery phase in Henoch–Schönlein purpura rabbit model

Preliminary study on assessing skin changes in Henoch-Schönlein purpura patients using high-frequency ultrasound and shear wave elastograph

Henoch-Schönlein purpura (HSP) is a prevalent allergic vasculitis. We aimed to investigate the characteristics of skin lesions and assess the degree of the skin damage in HSP patients using high-frequency ultrasound (HFUS) and shear wave elastography (SWE). By leveraging these imaging modalities, we sought to provide an objective and quantitative method for the clinical assessment of HSP, offering valuable insights for the evaluation and management of this condition. Thirty patients diagnosed with HSP were included in the study group (Group B). Among them, patients were further categorized into three subgroups based on the timing of evaluation: Group B1 consisted of patients at the time of admission, Group B2 included patients at the time of discharge, and Group B3 comprised patients at the time of discontinuation of treatment. The control group (Group A) consisted of 30 healthy individuals from the Health Management Center. General clinical data were systematically gathered from both groups. 20 MHz HFUS and SWE were used to assess the thickness and stiffness of the dermis and hypodermis on the left anterior tibial skin of both groups. Laboratory parameters, including WBC, CRP, ESR, and IgE, were documented for the case group, and their correlations with MEmean, MEmax, and MEmin were analyzed. It was found that compared to Group A, the thickness and stiffness of the dermis and hypodermis were significantly increased in the Groups B1 and B2, with dermal stiffness also increased in the Group B3 (all P < 0.05). However, no significant differences were observed in the thickness of the dermis and hypodermis, as well as in the stiffness of hypodermal between the Group B3 and Group A (all P > 0.05). This study showed that the overall skin thickness and stiffness of HSP lesions increased compared to group A. HFUS and SWE can monitor the clinical efficacy of HSP and quantitatively assess the extent of skin involvement in HSP patients, providing clinicians with a precise ultrasound basis for more objective evaluation of treatment outcomes.

Proanthocyanidins alleviate Henoch-Schönlein purpura by mitigating inflammation and oxidative stress through regulation of the TLR4/MyD88/NF-κB pathway

OBJECTIVE

Investigate Proanthocyanidins (PCs) efficacy and mechanisms in treating Henoch-Schönlein purpura (HSP)-like rat models, focusing on inflammatory and oxidative stress (OS) responses.

METHODS

An HSP-like rat model was established using ovalbumin (OVA) injection, leading to symptoms mimicking HSP. The study measured inflammatory markers (IL-4, IL-17, TNF-α), OS markers (MDA, SOD, CAT), and assessed the TLR4/MyD88/NF-κB signaling pathway's involvement via histopathological and immunofluorescence analyses.

RESULTS

PCs treatment significantly improved HSP-like symptoms, reduced inflammatory cell infiltration, and decreased IgA deposition in renal mesangial areas. Serum analyses revealed that PCs effectively lowered IL-4, IL-17, TNF-α, and MDA levels while increasing SOD and CAT levels (p < 0.05). Crucially, PCs also downregulated TLR4, MyD88, and NF-κB expressions, highlighting the blockage of the TLR4-mediated signaling pathway as a key mechanism.

CONCLUSION

PCs show promising therapeutic effects in HSP-like rats by mitigating inflammatory responses and oxidative damage, primarily through inhibiting the TLR4/MyD88/NF-κB pathway. These findings suggest PCs as a potential treatment avenue for HSP, warranting further investigation.

The Immunologic Profiles of Kawasaki Disease Triggered by Mycoplasma pneumoniae Infection

OBJECTIVE

We compared the immunologic characteristics of mycoplasma pneumoniae-triggered Kawasaki disease (MP-KD) with Kawasaki disease (KD) not associated with mycoplasma pneumoniae (MP), with mycoplasma pneumoniae-triggered Henoch-Schönlein purpura (MP-HSP), and with healthy controls.

METHODS

Complement levels, cellular and humoral immunity were assessed in KD, in MP-KD, in MP-HSP, and in healthy children.

RESULTS

Of 622 children with KD, 74 had MP-KD. Complement C3 and CD4/CD8 ratio were significantly increased in MP-KD compared to KD. C3, C4, and the ratio of CD4/CD8 in the MP-KD group were higher than those in the MP-HSP group. IgA and CD56 were lower in the MP-KD group than the MP-HSP group.

CONCLUSIONS

Both C3 and polyclonal CD4+ T lymphocytes may be activated in the patients with MP-KD.

Serum immunoglobulin profiles in Chinese children with Henoch-Schönlein purpura

OBJECTIVE

The present study focuses on the associations of serum immunoglobulin with disease activity, relapse/recurrence and renal involvement in Henoch-Schönlein purpura (HSP) children.

METHODS

1683 Chinese children with HSP were recruited from January 2015 to January 2021. Laboratory data of blood samples and urine tests were collected. Renal biopsy was performed by the percutaneous technique. Patients' histories associated with HSP onset were obtained by interviews and questionnaires.

RESULTS

(1) IgA and IgE were dramatically elevated in HSP patients as compared with their normal values, and subject to a 1.75-3.09 fold and a 1.97-2.61 fold increase, respectively. (2) No significant correlation of the disease activity with IgA and IgE was determined, respectively. (3) The serum IgA levels were significantly lower in patients with relapse/recurrence than that in patients without relapse/recurrence, which may be attributed to the transmission of IgA-mediated immune complexes from blood to vessel walls. (4) No significant correlation was found between serum IgA, IgE levels and the pathological classification.

CONCLUSIONS

HSP children have marked disorders of serum immunoglobulin profiles, characterized by significant increases in IgA and IgE. The detection of serum IgA may be applicable to predict relapse/recurrence of HSP, whereas not associated with disease activity and renal involvement.

Epidemiology and Clinical Characteristics of Henoch-Schönlein Purpura Associated with Epstein-Barr Virus Infection

Background

Henoch-Schönlein purpura (HSP) is an immune-mediated vasculitis, and the formation of immune complexes may be triggered by exposure to Epstein-Barr virus (EBV) infection.

Methods

We performed a five-year case-control study to evaluate the epidemiology and clinical characteristics of HSP associated with EBV infection.

Results

The incidence of EBV-triggered HSP was 4.2%, while EBV infection in children with HSP was 0.9%; The EBV-triggered HSP cases had a significantly higher frequency of abdominal pain than the Mycoplasma Pneumoniae (MP)-triggered HSP group (χ2 = 8.024, p = 0.005); Significant differences were observed in the duration of abdominal pain (Z = -1.935, p = 0.027) between the two groups; C3 (t = 9.709, p < 0.001), IgA (t = 20.39, p < 0.001) and IgG (t = 6.407, p < 0.001) were significantly increased in the EBV infection group than those in the healthy control group. Notably, significantly higher proportion of CD19 (t = 6.773, p < 0.001) and lower proportion of CD56 (t = 11.13, p < 0.001) was found in EBV infection group compared with healthy control group. The IgA level was higher than that of the non-infectious group (t = 2.162, p = 0.032), but their CD4/CD8 ratio (t = 10.070, p < 0.001) and CD56 proportion (t = 2.096, p = 0.037) were significantly lower.

Conclusions

Both cellular and humoral immunity were involved in the pathogenesis of EBV-triggered HSP, leading to increased production of inflammatory mediators and immunoglobulins. Those events may cause or promote the development of systemic vessel vasculitis.

Characteristics of immune function in the acute phase of Henoch-Schönlein purpura

BACKGROUND

Henoch-Schönlein purpura (HSP) is still diagnosed using symptoms and signs together with some histopathological findings. The purpose of this study was to summarize the characteristics and roles of cellular and humoral immunity in children with Henoch-Schönlein purpura (HSP).

METHODS

A total of 502 cases of patients with acute HSP were diagnosed and observed. The levels of T lymphocyte subsets, natural killer cells (NK cells), and B cells were analyzed by flow cytometry. The serum immunoglobulin G (IgG), immunoglobulin M (IgM), immunoglobulin A (IgA), and complement C3 (C₃) and complement C4 (C₄) levels were detected by velocity scatter turbidimetry.

RESULTS

Compared with the healthy groups, the levels of cluster of differentiation 3 (CD₃), cluster of differentiation 4 (CD₄), B cells, and NK cells and ratio of CD₄/CD₈ in patients with HSP were decreased (P < 0.05). The levels of IgG, IgA, IgM, and C₃ were increased (P < 0.05). Compared with the Kawasaki disease (KD) group, the levels of CD₃, CD₄, CD₈, B cells, NK cells, and IgA in patients with HSP were increased (P < 0.05), and the ratio of CD₄/CD₈ and levels of IgM, C₃, and C₄ was decreased (P < 0.05). Compared with the pneumonia group, the levels of CD₃, CD₄, B cells, and IgA in patients with HSP were increased (P < 0.05), and the ratio of CD₄/CD₈ and levels of IgM and C₄ was decreased (P < 0.05).

CONCLUSIONS

Cellular immunity and humoral immunity were all involved in the pathogenesis of HSP. The decline of NK cells, B lymphocyte cells, CD₃, CD₄ the increased secretion of immunoglobulin, and the abnormal appearance of IgA and C₃ may exist during the progression. It may indicate a worse prognosis and increasing the risk of dedifferentiation. Cellular immunity was lower, which lead to increased production of inflammatory mediators and increased secretion of immunoglobulin, which then mediated systemic small-vessel vasculitis. Key Points • The pathogenesis of Henoch-Schönlein purpura (HSP) was not completely illuminated. • There was a lack of disease-specific laboratory abnormalities that can be used in the clinical diagnosis of HSP. • We compared the laboratory abnormalities in the immune system of HSP with KD and pneumonia. • Cellular immunity and humoral immunity were all involved in the pathogenesis of HSP. Cellular immunity was lower, which lead to the following pathological changes.

New insights in the pathogenesis of immunoglobulin A vasculitis (Henoch-Schönlein purpura)

Immunoglobulin A vasculitis (IgAV), also referred to as Henoch-Schönlein purpura, is the most common form of childhood vasculitis. The pathogenesis of IgAV is still largely unknown. The disease is characterized by IgA1-immune deposits, complement factors and neutrophil infiltration, which is accompanied with vascular inflammation. Incidence of IgAV is twice as high during fall and winter, suggesting an environmental trigger associated to climate. Symptoms can resolve without intervention, but some patients develop glomerulonephritis with features similar to IgA nephropathy that include hematuria, proteinuria and IgA deposition in the glomerulus. Ultimately, this can lead to end-stage renal disease. In IgA nephropathy immune complexes containing galactose-deficient (Gd-)IgA1 are found and thought to play a role in pathogenesis. Although Gd-IgA1 complexes are also present in patients with IgAV with nephritis, their role in IgAV is disputed. Alternatively, it has been proposed that in IgAV IgA1 antibodies are generated against endothelial cells. We anticipate that such IgA complexes can activate neutrophils via the IgA Fc receptor FcαRI (CD89), thereby inducing neutrophil migration and activation, which ultimately causes tissue damage in IgAV. In this Review, we discuss the putative role of IgA, IgA receptors, neutrophils and other factors such as infections, genetics and the complement system 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.