Differences in pathological characteristics and laboratory indicators in adult and pediatric patients with Henoch-Schönlein purpura nephritis

Imbalanced Th17/Treg in peripheral blood of adult patients with immunoglobulin A vasculitis nephritis

Introduction

Adult immunoglobulin A vasculitis nephritis (IgAVN) was observed to be more severe than the disease in children because it tended to result in a poor prognosis. The present study analyzed the Th17/Treg cell axis in peripheral blood of adult IgAVN patients, aiming to provide new immunological viewpoints for the pathogenesis of adult IgAVN.

Material and methods

Th17 cell and Treg cell frequencies in peripheral blood of healthy subjects (n = 13) and adult IgAVN patients (n = 12) were analyzed by flow cytometry. Foxp3 mRNA in peripheral blood of healthy subjects and adult IgAVN patients was detected by RT-PCR. Interleukin (IL)-17 and IL-10 in peripheral blood serum of healthy subjects and adult IgAVN patients were examined by ELISA.

Results

The percentages of CD4⁺ Th17⁺ cells in peripheral blood of healthy subjects and adult IgAVN patients were 2.65 ±1.55% and 4.37 ±1.68% respectively. The percentages of Treg cells in peripheral blood of healthy subjects and adult IgAVN patients were 6.44 ±2.90% and 3.91 ±1.94% respectively. The ratio of Th17/Treg in adult IgAVN patients was significantly higher than that of healthy subjects (p = 0.0030). Meanwhile, the Foxp3 mRNA expression of adult IgAVN patients was significantly lower than that of healthy subjects. There was a significant difference in the ratio of IL-17/IL-10 between healthy subjects and adult IgAVN patients (p < 0.0001). A significant correlation between red blood cell distribution width (RDW) and the ratio of Th17/Treg in adult IgAVN patients was observed in Spearman correlation analysis (r = 0.6970, p = 0.0145).

Conclusions

Imbalanced Th17/Treg contributed to the complex pathogenesis of adult IgAVN.

Comparing immunoglobulin A vasculitis (Henoch-Schönlein purpura) in children and adults: a single-centre study from Turkey

OBJECTIVE

Immunoglobulin A vasculitis/Henoch-Schönlein purpura (IgAV/HSP) is a systemic vasculitis involving small vessels with the deposition of immune complexes containing IgA. It is the most common primary systemic vasculitis of childhood and is much less common in adults. Our aim was to investigate the differences and similarities between adult and paediatric patients with IgAV/HSP.

METHOD

We retrospectively evaluated the medical records of 35 adult and 159 paediatric (˂ 18 years old) patients with a clinical diagnosis of IgAV/HSP who were seen at the Departments of Rheumatology and Pediatric Rheumatology, Hacettepe University, Ankara, Turkey. The paediatric and adult patients were classified with IgAV/HSP according to the Ankara 2008 and American College of Rheumatology 1990 criteria, respectively.

RESULTS

Upper respiratory tract infection was a common predisposing factor for both adults (34.3%) and children (21.4%). Creatinine and C-reactive protein were higher; and skin biopsy, hypertension, renal involvement, haematuria, proteinuria, and renal insufficiency at diagnosis were more frequent in adults than in children. Thrombocyte count was higher in children than in adults. Follow-up without treatment and complete recovery were more frequent in children, while persistent haematuria, chronic renal failure, relapse, and the use of corticosteroids/azathioprine were more frequent in adults. The only independent predictive factor for relapse was persistent haematuria.

CONCLUSION

Various clinical and laboratory characteristics differ between children and adults with IgAV/HSP. Overall, IgAV/HSP has a self-limiting course in children but represents a more severe form of disease in adults, with more severe renal involvement. Persistent haematuria is a predictive factor for relapse.