Complication of chronic eosinophilic pneumonia in an elderly patient with Sjögren syndrome

Effects of chemokine receptor 3 gene silencing by RNA interference on eosinophils

The present study aimed to use RNA interference (RNAi) to silence chemokine receptor 3 (CCR3) and observe the effects on eosinophils (EOS) in mice with allergic rhinitis (AR). CCR3 small interfering RNA (siRNA) lentiviral vectors were transduced into purified EOS cells cultured in vitro. Reverse transcription-polymerase chain reaction (RT-PCR) and western blot analyses were also used to detect the efficiency of silencing, and flow cytometry was used to detect the EOS apoptosis rates. Experimental mice were grouped for nasal administration, and the lentivirus was then dispensed to AR mice. RT-PCR and western blots were performed to detect the expression levels of CCR3 mRNA and protein in EOS extracted from bone marrow, peripheral blood and nasal mucosa. Furthermore, flow cytometry was performed to detect changes to CD34-positive (CD34⁺) cells in each group. The CCR3 siRNA lentiviral vector exhibited high efficiency in silencing CCR3 mRNA and protein expression, inhibited growth and promoted apoptosis of EOS. In addition, the expression of CCR3 mRNA and protein in the bone marrow, peripheral blood and nasal mucosa of mice in the CCR3 siRNA treatment group were lower than those in the control group (P<0.05), whereas the number of CD34⁺ cells in the CCR3 siRNA treatment group was not significantly different compared with that in the control group (P>0.05). CCR3 RNAi could effectively silence the expression of CCR3 mRNA and protein both in vitro and in vivo, thus promoting apoptosis of EOS and inhibiting its growth, migration and invasion.

Associations between peripheral blood eosinophil counts in patients with systemic sclerosis and disease severity

Increased levels of serum pro-fibrotic cytokines have been reported in patients with systemic sclerosis (SSc). Some of these cytokines also play an important role in the differentiation and migration of eosinophils. The aim of this study was to determine whether eosinophilic inflammation is caused in SSc. We retrospectively reviewed the peripheral blood eosinophil counts in 70 untreated patients with SSc and compared them with those in patients with other major collagen diseases. We additionally evaluated a possible association with disease severity. Eosinophil counts were significantly higher levels in patients with SSc than in those with other collagen diseases, whereas total leukocyte counts were not. Eosinophil counts correlated positively with both severe interstitial lung disease (ILD; r = 0.255, p = 0.033) and modified Rodnan total skin thickness score (m-Rodnan TSS) in SSc (r = 0.347, p = 0.003), but did not correlate with ILD severity in other collagen diseases. In conclusion, peripheral eosinophil counts were higher in patients with SSc than in those with other collagen diseases and were correlated with increased disease severity. Our data suggest that eosinophilic inflammation is involved in the pathogenesis and progression of SSc.