Capsule endoscopy for small‐intestinal disorders: Current status

Small‐bowel capsule endoscopy (SBCE) is used widely because of its non‐invasive and patient‐friendly nature. SBCE can visualize entire small‐intestinal mucosa and facilitate detection of small‐intestinal abnormalities. In this review article, we focus on the current status of SBCE. Several platforms for SBCE are available worldwide. Third‐generation SBCE (PillCam^® SB3) has a high‐resolution camera equipped with an adaptive frame rate system. Several software modes have been developed to reduce the reading time for capsule endoscopy and to minimize the possibility of missing lesions. The main complication of SBCE is capsule retention. Thus, the main contraindication for SBCE is known or suspected gastrointestinal obstruction unless intestinal patency is proven. Possible indications for SBCE are obscure gastrointestinal bleeding, Crohn's disease, small‐intestinal polyps and tumors, and celiac disease. Colon capsule endoscopy (CCE) can observe inflamed colonic mucosa non‐invasively, and allows for the continuous and non‐invasive observation of the entire intestinal tract (pan‐endoscopy). Recently, application of CCE as pan‐enteric endoscopy for inflammatory bowel diseases (including Crohn's disease) has been reported. In the near future, reading for CE will be assisted by artificial intelligence, and reading CE videos for long periods will not be required.     

How I do it: Endoscopic diagnosis for superficial non-ampullary duodenal epithelial tumors

There are no reports on detailed endoscopic diagnosis of superficial non-ampullary duodenal epithelial tumors (SNADET) except for relatively small case series. Herein, we conducted a prospective observational study to investigate the relationship between endoscopic findings and histopathological diagnosis of SNADET. A total of 163 SNADET diagnosed using magnified endoscopic examination with image-enhanced endoscopy (IEE-ME) were prospectively registered in this study. We investigated location, size, macroscopic type, color, and IEE-ME findings including surface structure (closed- or open-loop) and presence of white opaque substance (WOS) in SNADET. We analyzed association between these findings and histopathological diagnosis of SNADET based on the Vienna classification (VCL) using logistic regression analysis. In univariate analysis, lesion size, superficial structure, and WOS deposition showed statistical significance, and the oral side of the lesion location showed statistical tendency for association with VCL C4/5. In multivariate analysis, lesion size (odds ratio [OR], 2.92; 95% CI, 1.94–4.39; P < 0.05) and negative WOS (OR, 5.59; 95% CI, 1.72–18.1; P < 0.05) were significantly associated with VCL C4/5 lesions. Superficial structures with a closed-loop pattern on the surface showed statistical tendency for predicting VCL C4/5 lesions (OR, 2.15; 95% CI, 0.86–5.37; P = 0.10). Based on these findings, we concluded that negative WOS by IEE-ME and lesion size were independent predictors of VCL C4/5 SNADET. These factors may help us to understand of pathophysiology of SNADET and to select appropriate therapeutic strategies.     

MAP-based kinetic analysis for voxel-by-voxel compartment model estimation: detailed imaging of the cerebral glucose metabolism using FDG

We propose a novel algorithm for voxel-by-voxel compartment model analysis based on a maximum a posteriori (MAP) algorithm. Voxel-by-voxel compartment model analysis can derive functional images of living tissues, but it suffers from high noise statistics in voxel-based PET data and extended calculation times. We initially set up a feature space of the target radiopharmaceutical composed of a measured plasma time activity curve and a set of compartment model parameters, and measured the noise distribution of the PET data. The dynamic PET data were projected onto the feature space, and then clustered using the Mahalanobis distance. Our method was validated using simulation studies, and compared with ROI-based ordinary kinetic analysis for FDG. The parametric images exhibited an acceptable linear relation with the simulations and the ROI-based results, and the calculation time took about 10 min. We therefore concluded that our proposed MAP-based algorithm is practical.     

Selective reduction and recovery of invariant Valpha24JalphaQ T cell receptor T cells in correlation with disease activity in patients with systemic lupus erythematosus

OBJECTIVE: To study the regulatory role of CD4-CD8- double-negative (DN) invariant T cell receptor (TCR) Valpha24JalphaQ T cells, a human counterpart of murine NK 1 + T cells, in the autoimmune process of systemic lupus erythematosus (SLE). METHODS: We carried out a 2 step frequency analysis of DN Valpha24JalphaQ T cells in patients with SLE before and after prednisolone therapy; the frequency of DN Valpha24+ T cells was determined by 3 color FACS analysis and subsequently the frequency of Valpha24JalphaQ rearrangement among DN Valpha24+ T cells was determined by sequencing. RESULTS: DN Valpha24+ T cells were significantly increased in patients with active SLE compared to healthy subjects. In healthy subjects, invariant Valpha24JalphaQ TCR dominated in DN Valpha24+ T cells at a high frequency (93-100%). However, the invariant Valpha24JalphaQ TCR was not detected in DN Valpha24+ T cells from patients with active SLE, and instead 2 to 9 Jalpha genes other than the invariant JalphaQ were oligoclonally expanded in the patients. In inactive SLE induced by prednisolone therapy, the invariant Valpha24JalphaQ TCR could be detected in DN Valpha24+ T cells from all the patients and dominated in most of the patients. Further, oligoclonally expanded Valpha24+ clones other than the invariant JalphaQ gene in active disease states were significantly decreased by prednisolone therapy. CONCLUSION: The selective reduction of DN invariant Valpha24JalphaQ T cells is related to the disease progression of SLE, while DN TCR Valpha24 T cells other than Valpha24JalphaQ T cells constitute autoaggressive T cells in SLE.     

Comparing the effectiveness of biological disease-modifying antirheumatic drugs using real-world data

Objectives: The objective of this study is to compare the effectiveness of biological disease-modifying antirheumatic drugs (bDMARDs) by analyzing claims data of 13 Japanese national university hospitals.

Methods: We evaluated 4970 cases of rheumatoid arthritis treated with bDMARDs from the Clinical Information Statistical Analysis database, which has collected and integrated 13 Japanese national university hospitals’ claims data for 10 years. We surveyed the medications and calculated the retention rates of bDMARDs using the Kaplan–Meier method and differentiated the effectiveness between the two bDMARDs by comparing the retention rates after switching from one drug to another.

Results: Of the 4970 cases, 1364 switched bDMARDs at least once. Tocilizumab (TCZ) reported the highest retention rate, whereas abatacept (ABT) revealed a similar rate compared with only naïve cases. The retention rate curves were higher in cases on TCZ that switched from the other bDMARDs than those in the reversed cases. Following TCZ, ABT and etanercept indicated better results than the other bDMARDs.

Conclusion: We could compare the effectiveness among bDMARDs by differentiating the retention rates from big claims data. TCZ reported higher retention rates in both naïve and switched cases than other bDMARDs.