Clinicopathological analysis of immunohistochemical expression of CD47 and SIRPα in adult T-cell leukemia/lymphoma

The interaction of CD47 and signal-regulatory protein alpha (SIRPα) induces “don't eat me signal”, leading suppression of phagocytosis. This signal can affect the clinical course of malignant disease. Although CD47 and SIRPα expression are associated with clinicopathological features in several neoplasms, the investigation for adult T-cell leukemia/lymphoma (ATLL) has not been well-documented. This study aimed to declare the association between CD47 and SIRPα expression and clinicopathological features in ATLL. We performed immunostaining on 73 biopsy samples and found that CD47 is primarily expressed in tumor cells, while SIRPα is expressed in non-neoplastic stromal cells. CD47 positive cases showed significantly higher FoxP3 (P = .0232) and lower CCR4 (P = .0214). SIRPα positive cases presented significantly better overall survival than SIRPα negative cases (P = .0132). SIRPα positive cases showed significantly HLA class I (P = .0062), HLA class II (P = .0133), microenvironment PD-L1 (miPD-L1) (P = .0032), and FoxP3 (P = .0229) positivity. In univariate analysis, SIRPα expression was significantly related to prognosis (Hazard ratio [HR] 0.470; 95% confidence interval [CI] 0.253-0.870; P = .0167], although multivariate analysis did not show SIPRα as an independent prognostic factor. The expression of SIRPα on stromal cells reflects activated immune surveillance mechanism in tumor microenvironment and induce good prognosis in ATLL. More detailed studies for gene expression or genomic abnormalities will disclose clinical and biological significance of the CD47 and SIRPα in ATLL.     

Significance of the gut microbiome in multistep colorectal carcinogenesis

Colorectal cancer (CRC) is highly prevalent worldwide. In 2018, there were over 1.8 million new cases. Most sporadic CRC develop from polypoid adenomas and are preceded by intramucosal carcinoma (stage 0), which can progress into more malignant forms. This developmental process is known as the adenoma‐carcinoma sequence. Early detection and endoscopic removal are crucial for CRC management. Accumulating evidence suggests that the gut microbiota is associated with CRC development in humans. Comprehensive characterization of this microbiota is of great importance to assess its potential as a diagnostic marker in the very early stages of CRC. In this review, we summarized recent studies on CRC‐associated bacteria and their carcinogenic mechanisms in animal models, human cell lines and human cohorts. High‐throughput technologies have facilitated the identification of CRC‐associated bacteria in human samples. We have presented our metagenome and metabolome studies on fecal samples collected from a large Japanese cohort that revealed stage‐specific phenotypes of the microbiota in CRC. Furthermore, we have discussed the potential carcinogenic mechanisms of the gut microbiota, from which we can infer whether changes in the gut microbiota are a cause or effect in the multi‐step process of CRC carcinogenesis.     

Solid‐type poorly differentiated adenocarcinoma of the stomach: Deficiency of mismatch repair and SWI/SNF complex

ARID1A, one of the subunits in SWI/SNF chromatin remodeling complex, is frequently mutated in gastric cancers with microsatellite instability (MSI). The most frequent MSI in solid‐type poorly differentiated adenocarcinoma (PDA) has been reported, but the SWI/SNF complex status in solid‐type PDA is still largely unknown. We retrospectively analyzed 54 cases of solid‐type PDA for the expressions of mismatch repair (MMR) proteins (MLH1, PMS2, MSH2, and MSH6), SWI/SNF complex subunits (ARID1A, INI1, BRG1, BRM, BAF155, and BAF170) and EBER, and mutations in KRAS and BRAF. We analyzed 40 cases of another histological type of gastric cancer as a control group. The solid‐type PDAs showed coexisting glandular components (76%), MMR deficiency (39%), and complete/partial loss of ARID1A (31%/7%), INI1 (4%/4%), BRG1 (48%/30%), BRM (33%/33%), BAF155 (13%/41%), and BAF170 (6%/2%), EBER positivity (4%), KRAS mutation (2%), and BRAF mutation (2%). Compared to the control group, MMR deficiency and losses of ARID1A, BRG1, BRM, and BAF155 were significantly frequent in solid‐type PDAs. Mismatch repair deficiency was associated with the losses of ARID1A, BRG1, and BAF155 in solid‐type PDAs. In the MMR‐deficient group, solid components showed significantly more frequent losses of ARID1A, BRG1, BRM, and BAF155 compared to glandular components (P = .0268, P = .0181, P = .0224, and P = .0071, respectively). In the MMR‐proficient group, solid components showed significantly more frequent loss of BRG1 compared to glandular components (P = .012). In conclusion, solid‐type PDAs showed frequent losses of MMR proteins and the SWI/SNF complex. We suggest that loss of the SWI/SNF complex could induce a morphological shift from differentiated‐type adenocarcinoma to solid‐type PDA.     

Successful remission using metyrapone in an elderly patient with Cushing disease accompanied by generalized edema

An 82-year-old woman was referred to our hospital because of hypoalbuminemia and generalized edema. Hypercortisolemia was subsequently found as the levels of serum cortisol and plasma adrenocorticotropic hormone (ACTH) sampled in a fasting morning were 140 pg/mL and 41.9 μg/dL, respectively. These hormones were not suppressed after taking low-dose dexamethasone the previous night and increased to a mild extent in response to administration of corticotrophin-releasing hormone, suggesting presence of pituitary adenoma producing ACTH (Cushing's disease). However, intrasella localization of pituitary adenoma could not be determined by magnetic resonance imaging. Soon after administration of metyrapone was started in an attempt to reduce her cortisol levels, the patient suffered from severe pneumonia. The pulmonary infection and peripheral edema were improved with decreases in cortisol levels by continuing metyrapone administration with antibiotics and finally she was discharged from the hospital on foot. Metyrapone is a useful therapeutic choice to achieve a remission of cortisol levels in the elderly patients with Cushing's disease in association with serious hypercortisolemia impending severe infection.     

Leflunomide-related lung injury in patients with rheumatoid arthritis: imaging features

Imaging findings of 26 cases of leflunomide (Arava)-related acute lung injury were analyzed. Thirteen cases had pre-existing interstitial pulmonary disease on chest X-ray or computed tomography. The main features of clinically determined leflunomide-induced acute lung injury were similar to those caused by other drugs: diffuse or widespread patchy ground-glass opacities and/or consolidation, frequently accompanied by septal thickening and intralobular reticular opacities. We categorized these findings into four patterns: diffuse alveolar damage (DAD), acute eosinophilic pneumonia, hyperreaction, and cryptogenic organizing pneumonia. The DAD group had a higher mortality rate, but statistically not a significant one. It is impossible to exclude infectious disease such as pneumocystis carinii pneumonia based on imaging findings, and detailed correlation of imaging findings with clinical and laboratory findings is essential in order to make a correct diagnosis.