CD4+ T cells in aged or thymectomized recipients of allogeneic stem cell transplantations

BACKGROUND: CD4+CD25highFOXP3+ regulatory T (Treg) cells, which include thymus-derived and peripherally induced cells, play a central role in immune regulation, and are therefore crucial to prevent graft-versus-host disease (GVHD). The increasing use of allogeneic hematopoietic stem cell transplantation (allo-HSCT) for elderly patients with thymus regression, and our case of allo-HSCT shortly after total thymectomy, raised questions about the activity of thymus-derived Treg cells and peripherally induced Treg cells, which are otherwise indistinguishable. RESULTS: We found that despite pre-transplant thymectomy or older age, both naïve and effector Treg cells, as well as naïve and effector conventional T cells, proliferated in allo-HSCT recipients. Higher proportions of total Treg cells 1 month post allo-HSCT, and naïve Treg cells 1 year post allo-HSCT, appeared in patients achieving complete chimera without developing significant chronic GVHD, including our thymectomized patient, compared with patients who developed chronic GVHD. CONCLUSIONS: Treg cells that modulate human allogeneic immunity may arise peripherally as well as in the thymus of allo-HSCT recipients.

Clinical Evaluation of Macrolide-resistant Mycoplasma pneumoniae Infections in Pediatric Japanese Patients.

Background: In recent years, an increase in Mycoplasma pneumoniae infections among children has become a social issue in Japan. Methods: During a 2-year collection period (2011-2012), we evaluated trends during the first and second halves of both years. Only patients with positive rapid antigen detection test results (ImmunoCard Mycoplasma: Meridian Bioscience, Inc Cincinnati, OH, USA) were included. The evaluation items included the patient number, sex, radiography findings, white blood cell (WBC) count, C-reactive protein (CRP) level, and clinical macrolide-resistance rate. Results: The patient number increased significantly during the latter halves of the years. The macrolide-resistance rate also increased during the same periods. A similar trend was observed with respect to radiography findings but not with respect to the WBC count and CRP level. Conclusions: It is important to monitor the macrolide-resistance trends in case of Mycoplasma pneumoniae infections in children.

Comparison in pathological behaviours & prognosis of gastric cancers from general hospitals between China & Japan.

Background & objective: Gastric cancer is the fourth most common cancer and the second leading cause of cancer-related deaths after lung carcinoma. The aim of this study was to understand the difference in clinicopathological behaviours and prognosis of gastric cancer in patients from China and Japan. Methods: Paraffin-fixed tissue samples of gastric cancer were collected retrospectively from two hospitals between 1993 to 2006 in Japan (n=2063) and during 1980-2003 in China (n=2496) respectively, and staging was done by TNM system and typing by Japanese Endoscopy Society criteria or Borrmann’s classification. The histological architecture of the tumours was expressed according to Lauren’s classification. Results: Compared to Japan, the occurrence of gastric cancer was more common in younger Chinese population and prone to invasion and metastasis in muscularis propia, lymphatic, lymph node, liver, peritoneal parts, and exhibited large tumour size and high TNM staging in both the sexes and in different age groups (P<0.05). Intestinal and mixed types of carcinomas were more frequently observed in Japanese patients compared to Chinese and the difference was significant (P<0.05). It was observed that the commonly reported types in early gastric cancers (EGC) in Japanese patients were IIc, IIa+IIc or IIa while those of Chinese patients were IIc, III or IIb. In the case of advanced gastric cancers (AGC), type II and III were most common in both the countries. The cumulative survival rate of Chinese patients was significantly (P<0.05) higher compared to Japanese in different stratified groups via depth of invasion, TNM staging or Lauren’s classification. Interpretation & conclusion: Gastric cancers in Chinese patients had more aggressive pathological characteristics and poorer prognosis than those from Japan. To reduce incidence and to improve treatment facilities, it is necessary to have a systematic screening system.