Imbalance towards Th1 pathway predominance in purpura nephritis with proteinuria

Involvement of activated cytotoxic T lymphocytes and natural killer cells in Henoch-Schönlein purpura nephritis

Objectives

Immunoglobulin A vasculitis/Henoch–Schönlein purpura (IgAV/HSP) is a major cause of vasculitis in children. It is often accompanied by nephritis (HSPN) and could progress to chronic kidney disease. Galactose‐deficient IgA₁ was recently reported to be involved in the pathogenesis of HSPN, for which immunosuppressive drugs are considered key treatment. However, the involvement of immune cells in the development of HSPN remains unclear.

Methods

We compared gene expressions of peripheral blood mononuclear cells (PBMCs) among healthy controls (n = 10), IgAV/HSP patients (n = 21) and HSPN patients (n = 8), which required nephritis development within 3 months of IgAV/HSP onset. Immunohistochemistry analysis and flow cytometry were performed to assess renal biopsy specimens and PBMCs, respectively. Serum CX3CL1 levels were measured by ELISA.

Results

GNLY and GZMB expressions increased in HSPN patients, consistent with increased number of glomerular granulysin‐ and/or granzyme B‐positive cells demonstrated by immunohistochemistry analysis. Additionally, circulating cytotoxic T lymphocytes (CTLs) and natural killer (NK) cells were activated with the up‐regulated surface expressions of human leucocyte antigen DR (HLA‐DR) and CX3CR1 in HSPN patients with severe proteinuria. Renal biopsies demonstrated increased number of CD8⁺ cells and/or CD56⁺ cells and up‐regulated expression of glomerular CX3CL1, a specific ligand for CX3CR1, along with increased serum CX3CL1 level.

Conclusion

Activated CTLs and NK cells play roles in the development of nephritis in IgAV/HSP patients and can be used as novel biomarkers for HSPN.

The Effect of Chinese Traditional Medicine Huaiqihuang (HQH) on the Protection of Nephropathy

Kidney disease is one of the common diseases with high morbidity and high mortality, which brings a huge burden to the society and the patient's family. The pathogenesis, treatment, and prognosis of kidney diseases are related to oxidative stress, inflammation, mitochondrial damage, and immune dysfunction. However, existing treatments always cause some damage to the kidneys. Kidney disease and immunosuppressant used together often lead to drug toxicity, patients with weakened immunity, organic rupture of the normal structure of the kidney, damage to the physiological function of the kidney, etc. Huaiqihuang is a kind of traditional Chinese medicine with a history of more than one thousand years. According to research, Robinia pseudoacacia can regulate the immune function by regulating oxidative stress, calcium inflow, and mitochondrial ATP. At the same time, it is also involved in regulating the ways of cell death, such as apoptosis, autophagy, ferroptosis, pyroptosis, and clockophagy, to reduce kidney damage, which has important clinical value. This article reviews the exact mechanism and clinical application of Huaiqihuang in different types of nephropathy. The aim is to provide new ideas for the treatment of clinical nephropathy.

Beneficial Effects of Qingzixiaoban Granule on Henoch–Schönlein Purpura Nephritis Mice through Inhibiting Immune Complex Deposition and Th2 Immunodeviation

Background

Henoch–Schönlein purpura nephritis (HSPN) is the principal cause of morbidity and mortality in Henoch–Schönlein purpura (HSP). However, there is no absolute consensus for the best management of severe HSPN till now. Qingzixiaoban Granule (QZXB GR), a traditional Chinese medicine formula, has been applied to treat HSP in clinical in China. However, the therapeutic effects and potential mechanism of QZXB GR on HSPN is still unknown.

Methods

A Gliadin plus Indian Ink-induced HSPN mice model was established. Renal histopathologic changes and the subcutaneous hemorrhage on left legs were assessed. Hematuria and proteinuria were determined using hemocytometer and bicinchoninic acid assay, respectively. The serum circular immune complex and interleukin-6 were quantified by ELISA. Using blood biochemical analyzer, the renal biochemical parameters, including serum total protein, albumin, creatinine, and blood urea nitrogen, were measured. The deposition of immune complex in renal tissues and the lymphocyte subsets in peripheral blood and spleen was investigated by immunohistochemistry and flow cytometry.

Results

QZXB GR treatment significantly ameliorated renal injury in HSPN mice, by attenuating renal histopathological changes, reducing subcutaneous hemorrhage, decreasing proteinuria/hematuria, regulating renal biochemical parameters, and inhibiting the release of serum interleukin-6. Furthermore, QZXB GR treatment significantly decreased the level of serum circular immune complex, decreased immune complex IgA and IgG deposition in renal tissue, and suppressed Th2 immunodeviation.

Conclusion

QZXB GR could prevent renal injury in HSPN mice, and its renoprotective mechanism might be exerted partly through suppressing immune complexes deposition and Th2 immune deviation.

Expressions of mRNA for innate immunity-associated functional molecules in urinary sediment in immunoglobulin A nephropathy

AIM

It has been reported that the innate immune system plays a pivotal role in the pathogenesis of immunoglobulin A nephropathy (IgAN). To explore non-invasive monitoring of disease activity in children with IgAN, we examined whether expressions of mRNA for innate immunity-associated functional molecules: CC ligand chemokine 5 (CCL5), fractalkine/CX3CL1, interferon-γ-induced protein 10 (IP-10), monocyte chemoattractant protein 1 (MCP-1), retinoic acid-inducible gene-I (RIG-I), and toll-like receptor 3 (TLR3) in urinary sediment from patients with IgAN correlate with histologic parameters.

METHODS

Twenty consecutive children with IgAN and four children with thin basement membrane disease (serving as a non-inflammatory control) were enrolled in this pilot study. Urinary mRNA expressions of target genes were examined real-time quantitative polymerase chain reaction.

RESULTS

The expressions of CCL5, fractalkine and RIG-I were significantly increased in IgAN (all P < 0.05). Although no significant correlation was observed between mRNA expressions of these three molecules and clinical parameters, such as levels of urinary protein excretion, degrees of occult blood in urine and serum albumin, the expression of fractalkine was significantly correlated with the histological activity index (P = 0.022) and the chronicity index (P = 0.005). Furthermore, intense glomerular immune activity of fractalkine was observed in biopsy specimens in patients with moderately to severe proliferative IgAN.

CONCLUSION

Regional expression of fractalkine may be involved in the pathogenesis of childhood IgAN. Although our present findings remain preliminary, measurement of mRNA expression of fractalkine in urinary sediment could be used as a non-invasive method for predicting histologic severity in IgAN in children. Further studies of this issue are needed.

Studying cytokines of T helper cells in the kidney disease of IgA vasculitis (Henoch-Schönlein purpura)

BACKGROUND

Immunoglobulin A vasculitis (IgA-V), formerly known as Henoch-Schönlein purpura (HSP), is the most common small vessel vasculitis in children. In recent years, the role of T cells in the pathogenesis of HSP/IgA-V has become a focus of research.

METHODS

Renal biopsy specimens from 22 pediatric patients diagnosed with Henoch-Schönlein nephritis (patient group) were compared to normal renal tissue in nephrectomy specimens from 20 pediatric patients diagnosed with Wilms tumor (control group). All renal specimens were scored according to International Study of Kidney Disease in Children (ISKDC) and Oxford classification. Immunohistochemical analyses of interferon-gamma (IFN-γ), interleukin (IL)-4, IL-17 and FOXP3 expression were performed.

RESULTS

All glomeruli and tubules of the HSP/IgA-V patients showed significantly higher IFN-γ and IL-17 expression than those of the control group. Glomerular IFN-γ and IL-17 staining grades correlated with the urinary protein/creatinine ratio (r = 0.62, p = 0.02 and r = 0.507, p = 0.016, respectively). IL-17 expression also correlated with the percentage of crescents (r = 0.518, p = 0.014). IL-4 staining was present in only nine of the 22 patient biopsies and did not correlate with any of the parameters studied. Interstitial areas of patient biopsies had more FOXP3+ cells/μm(2) than those of the control group (p < 0.001), but differences in glomerular and tubular FOXP3+ levels (cells/μm(2)) between the two groups were not statistically different. The ISKDC and Oxford scores did not correlate with any parameter studied. However, endocapillary hypercellularity did correlate with IFN-γ expression.

CONCLUSIONS

Based on these results, we conclude that IFN-γ and IL-17 contribute to HSP/IgA-V in children.

24h Urinary Protein Levels and Urine Protein/Creatinine Ratios Could Probably Forecast the Pathological Classification of HSPN

This study aimed to assess the relevance of laboratory tests in Henoch-Schönlein purpura nephritis (HSPN) classification, and determine accurate classification factors. This prospective study included 694 HSPN patients who underwent ultrasound-guided percutaneous renal biopsy (PRB). Renal specimens were scored according to International Study of Kidney Disease in Children (ISKDC) classification. Meanwhile, blood samples were immediately collected for laboratory examination. The associations between laboratory parameters and HSPN classification were assessed. Significant differences in levels of serum Th1/Th2 cytokines, immunoglobulins, T-lymphocyte subsets, complement, and coagulation markers were obtained between HSPN patients and healthy children. Interestingly, 24h urinary protein (24h-UPRO) levels and urine protein/urine creatinine ratios could determine HPSN grade IIb, IIIa, and IIIb incidences, with areas under ROC curve of 0.767 and 0.731, respectively. At 24h-UPRO >580.35mg/L, prediction sensitivity and specificity were 75.2% and 70.0%, respectively. These values became 53.0% and 82.3%, respectively, with 24h-UPRO exceeding 1006.25mg/L. At urine protein/urine creatinine > 0.97, prediction sensitivity and specificity were 65.5% and 67.2%, respectively, values that became 57.4% and 80.0%, respectively, at ratios exceeding 1.2. Cell and humoral immunity, coagulation and fibrinolytic systems are all involved in the pathogenesis of HSPN, and type I hypersensitivity may be the disease trigger of HSPN. 24h-UPRO levels and urine protein/creatinine ratios could probably forecast the pathological classification of HSPN.

Henoch-Schönlein purpura in 535 Chinese children: clinical features and risk factors for renal involvement

OBJECTIVES

To analyse the clinical features of Henoch-Schönlein purpura (HSP) with or without nephritis in Chinese children and to determine the risk factors for renal involvement.

METHODS

Patient characteristics, clinical parameters and laboratory data were retrospectively analysed in patients with HSP with or without nephritis. Logistic regression analysis was used to identify the risk factors for renal involvement.

RESULTS

A total of 535 patients with HSP were included in the study. HSP nephritis occurred in 267 patients (49.9%), ranging from isolated haematuria in 5.2%, mild proteinuria in 77.5%, moderate proteinuria in 6.4% and severe proteinuria in 10.9% of cases. In 90% of the cases, nephritis developed within 1 week of HSP onset; 98.5% of the cases with nephritis developed the condition within 1 month. Risk factors for the development of nephritis were age ≥6 years, purpura on sites other than the lower limbs and the presence of occult blood in the stool.

CONCLUSION

These results suggest that patients aged ≥6 years, or who have purpura on the upper limbs or face, or who have occult blood in the stool should be particularly monitored for signs of nephritis.

Aberrant histone modifications in peripheral blood mononuclear cells from patients with Henoch-Schönlein purpura

Henoch-Schönlein purpura (HSP), the most common type of leukocytoclastic vasculitis, is caused by T cell-mediated autoimmune reactions. In this study, we analyze histone modification patterns in peripheral blood mononuclear cells (PBMCs) of HSP patients, and investigate the expression levels of inflammatory cytokines (IFN-γ, IL-2, IL-4, IL-6 and IL-13), transcription factors (T-bet, GATA-3 and TIM-1) and chemokines (CXCL4 and CXCL10) in HSP patients. Our results show that histone H3 acetylation and methylation are significantly enhanced in PBMCs from HSP patients. We also demonstrate specifically that marked increases in histone H3 acetylation and H3 lysine 4 trimethylation occur at the IL-4 loci in these patients. In addition, the expression levels of IL-4, IL-6, IL-13, GATA-3, TIM-1 and CXCL4 are also increased. These findings suggest that abnormal histone modifications are present in the PBMCs of patients with HSP, possibly contributing to the activation of pathological immune responses associated with HSP.