Analysis of treatment outcomes in patients with antineutrophil cytoplasmic antibody-associated vasculitis on rituximab therapy

Objectives

This study aimed to analyze a group of patients with severe and refractory antineutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV) managed with rituximab and to report on treatment outcomes.

Patients and methods

A total of 78 patients (41 females, 37 males; mean age: 50.1±13.4 years; range, 18 to 76 years) with AAV on rituximab treatment were included in the single-center, retrospective study conducted between 2009 and 2018. The diagnosis was established based on the 1990 classification criteria of the American College of Rheumatology and the definitions of vasculitis of Chapel Hill Consensus Conference. Laboratory and immunological tests were conducted. Disease activity was determined through the Birmingham Vasculitis Activity Score.

Results

Rituximab was preferred over cyclophosphamide in 37 patients and used as a second-line therapy after cyclophosphamide in 41 cases. Rituximab treatment showed favorable outcomes with regard to serum creatinine levels, proteinuria, and hematuria, as well as in cases of isolated lung involvement. Nearly half of patients with pulmonary renal syndrome also improved, with 22.2% achieving remission. ANCAs were positive in 85.9% of patients at the onset of rituximab treatment and became negative in 82% of the positive cases. Adverse events were rare and included infusion reactions (one case of reactivation of a herpes zoster infection and one case of allergic reaction).

Conclusion

Rituximab is an efficient and safe therapeutic option in patients with AAV who are difficult to treat, have insufficient response, or have not tolerated other treatments.

Alterations of serum levels of plasminogen, TNF-α, and IDO in granulomatosis with polyangiitis patients

BACKGROUND

Granulomatosis with polyangiitis (GPA) is a representative of vasculitides associated with anti-neutrophil cytoplasmic autoantibodies. "Classical" antibodies directed against proteinase 3 are involved in the pathogenesis and are part of the GPA diagnosis at the same time. Along with them, however, antibodies against Lysosomal-Associated Membrane Protein-2 (LAMP-2) and antibodies directed against plasminogen have been described in GPA.Objectives and methodology: We performed a cross-sectional study enrolling 34 patients diagnosed with GPA. Our study was aimed at looking for correlations between serum levels of LAMP-2 and plasminogen and the clinical manifestations of the GPA. Furthermore, we examined serum levels of tumor necrosis factor-alpha (TNF-α) and its associated indoleamine-pyrrole 2,3-dioxygenase (IDO), as well as we looked for a correlation between these cytokines and the clinical manifestations of GPA.

RESULTS

The results showed that in GPA, serum plasminogen levels were negatively associated with renal involvement (receiver operating characteristic (ROC) area under the curve (AUC) of 0.78) (95% CI 0.53-0.91), p = 0.035, and the extent of proteinuria, Spearman's Rho = -0.4, p = 0.015. Increased levels of TNF-α and IDO correlated with disease activity, Spearman's Rho =0.62, p = 0.001 and Spearman's Rho = 0.4, p = 0.022, respectively, whereas only TNF-α was increased in severe forms of GPA with lung involvement (ROC AUC of 0.8) (95% CI 0.66-0.94), p = 0.005.

CONCLUSIONS

In this study, we demonstrate the alteration of soluble factors, which play an important role in the pathogenesis of GPA and their relationship with the clinical manifestations of the disease. Our main results confirm the associations of increased secretory TNF-α and some clinical manifestations, and we describe for the first time decreased serum plasminogen levels and their association with renal involvement.

Treg/Th17 cell balance and phytohaemagglutinin activation of T lymphocytes in peripheral blood of systemic sclerosis patients

AIM

To investigate T-cell activation, the percentage of peripheral T regulatory cells (Tregs), Th17 cells and the circulating cytokine profile in systemic sclerosis (SSc).

METHODS

We enrolled a total of 24 SSc patients and 16 healthy controls in the study and divided the patients as having diffuse cutaneous SSc (dcSSc, n = 13) or limited cutaneous SSc (lcSSc, n = 11). We performed a further subdivision of the patients regarding the stage of the disease - early, intermediate or late. Peripheral venous blood samples were collected from all subjects. We performed flow cytometric analysis of the activation capacity of T-lymphocytes upon stimulation with PHA-M and of the percentage of peripheral Tregs and Th17 cells in both patients and healthy controls. We used ELISA to quantitate serum levels of human interleukin (IL)-6, IL-10, tissue growth factor-β1 (TGF-β1), and IL-17A.

RESULTS

We identified a decreased percentage of CD3+CD69+ cells in PHA-stimulated samples from SSc patients in comparison with healthy controls (13.35% ± 2.90% vs 37.03% ± 2.33%, P < 0.001). However, we did not establish a correlation between the down-regulated CD3+CD69+ cells and the clinical subset, nor regarding the stage of the disease. The activated CD4+CD25+ peripheral lymphocytes were represented in decreased percentage in patients when compared to controls (6.30% ± 0.68% vs 9.36% ± 1.08%, P = 0.016). Regarding the forms of the disease, dcSSc patients demonstrated lower frequency of CD4+CD25+ T cells against healthy subjects (5.95% ± 0.89% vs 9.36% ± 1.08%, P = 0.025). With regard to Th17 cells, our patients demonstrated increased percentage in comparison with controls (18.13% ± 1.55% vs 13.73% ± 1.21%, P = 0.031). We detected up-regulated Th17 cells within the lcSSc subset against controls (20.46% ± 2.41% vs 13.73% ± 1.21%, P = 0.025), nevertheless no difference was found between dcSSc and lcSSc patients. Flow cytometric analysis revealed an increased percentage of CD4+CD25-Foxp3+ in dcSSc patients compared to controls (10.94% ± 1.65% vs 6.88% ± 0.91, P = 0.032). Regarding the peripheral cytokine profile, we detected raised levels of IL-6 [2.10 (1.05-4.60) pg/mL vs 0.00 pg/mL, P < 0.001], TGF-β1 (19.94 ± 3.35 ng/mL vs 10.03 ± 2.25 ng/mL, P = 0.02), IL-10 (2.83 ± 0.44 pg/mL vs 0.68 ± 0.51 pg/mL, P = 0.008), and IL-17A [6.30 (2.50-15.60) pg/mL vs 0 (0.00-0.05) pg/mL, P < 0.001] in patients when compared to healthy controls. Furthermore, we found increased circulating IL-10, TGF-β, IL-6 and IL-17A in the lcSSc subset vs control subjects, as it follows: IL-10 (3.32 ± 0.59 pg/mL vs 0.68 ± 0.51 pg/mL, P = 0.003), TGF-β1 (22.82 ± 4.99 ng/mL vs 10.03 ± 2.25 ng/mL, P = 0.031), IL-6 [2.08 (1.51-4.69) pg/mL vs 0.00 pg/mL, P < 0.001], and IL-17A [14.50 (8.55-41.65) pg/mL vs 0.00 (0.00-0.05) pg/mL, P < 0.001]. Furthermore, circulating IL-17A was higher in lcSSc as opposed to dcSSc subset (31.99 ± 13.29 pg/mL vs 7.14 ± 3.01 pg/mL, P = 0.008). Within the dcSSc subset, raised levels of IL-17A and IL-6 were detected vs healthy controls: IL-17A [2.60 (0.45-9.80) pg/mL vs 0.00 (0.00-0.05) pg/mL, P < 0.001], IL-6 [2.80 (1.03-7.23) pg/mL vs 0.00 pg/mL, P < 0.001]. Regarding the stages of the disease, TGF-β1 serum levels were increased in early stage against late stage, independently from the SSc phenotype (30.03 ± 4.59 ng/mL vs 13.08 ± 4.50 ng/mL, P = 0.017).

CONCLUSION

It is likely that the altered percentage of Th17 and CD4+CD25-FoxP3+ cells along with the peripheral cytokine profile in patients with SSc may play a key role in the pathogenesis of the disease.