The Th17/IL-23 Axis and Natural Immunity in Psoriatic Arthritis

Psoriatic arthritis (PsA) is a chronic inflammatory skin disease that causes enthesitis and destructive arthritis and significantly lowers patient quality of life. Recognition of the two target organs (the skin and joints) involved in the immunopathophysiology of PsA helped in elucidating the pathology of various systemic autoimmune diseases targeting multiple organs. Recent advances in immunology and genetics have made it clear that acquired immunity, especially that mediated by the Th17/IL-23 axis, plays an important role in the inflammatory pathology observed in psoriasis and PsA. Additionally, involvement of natural immunity has also been suggested. Microbial infection has been known to trigger psoriasis and PsA. Recent clinical studies using biopharmaceuticals, such as tumor-necrosis-factor- (TNF-) α inhibitors and IL-12/23 p40 antibodies, indicate that studies need not be based only on the immunological phenomena observed in PsA pathology since disease pathology can now be verified using human-based science. Considering this aspect, this paper discusses the immunopathology of PsA compared to psoriasis (cutaneous) and rheumatoid arthritis in humans and immunopathology of PsA with respect to the Th17/IL-23 axis and microbial infection

Induction of class II major histocompatibility complex expression in human multiple myeloma cells by retinoid

Class II major histocompatibility complex (MHC II) is normally silenced in plasma/multiple myeloma (MM) cells at the transcriptional level through downregulation of class II transactivator (CIITA), allowing MM cells to escape from immunological responses. Here we demonstrate that a retinoic acid receptor-α/β-selective retinoid Am80 (tamibarotene) could induce the expression of functional MHC II molecules in human MM cell lines. Am80 upregulated expression of the interferon regulatory factor-1 gene, followed by enhancement of CIITA expression. This is the first report demonstrating that retinoid can induce the expression of MHC II in terminally-differentiated plasma/MM cells

Myofibroblasts proliferation of idiopathic and collagen vascular disorders associated nonspecific interstitial pneumonia.

Nonspecific interstitial pneumonia (NSIP) has been recognized as a separate histological classification of interstitial lung disease. Similar features are found not only in idiopathic NSIP, but also in NSIP associated with collagen vascular disorder (CVD-NSIP). We examined the clinical symptoms, laboratory findings, and prognosis of 13 cases of idiopathic NSIP and 11 cases of CVD-NSIP. Immunohistochemical staining was performed using the streptavidin/biotin/peroxidase method with anti-alpha-smooth muscle actin antibody. No differences in the distribution of clinical features, laboratory findings, and prognosis were observed between idiopathic NSIP and CVD-NSIP. In immunohistochemical staining of the fibrosing areas, myofibroblasts were observed in 7 of 13 idiopathic NSIP cases, but in 10 of 11 CVD-NSIP cases. With regards to intra-alveolar organization, myofibroblasts were observed in all 10 CVD-NSIP cases, but they were observed in only 2 of 9 idiopathic NSIP cases. We found a significantly higher myofibroblast proliferation in the intra-alveolar organization of CVD-NSIP compared to idiopathic NSIP. Clinically, idiopathic NSIP and CVD-NSIP are similar, but are pathologically different.</p

Persistence of Acquired Epileptogenesis in Amygdaloid-Kindled Rats: Relationship between the Initial Kindling Stages and Seizure Development in Rekindling

In order to gain insight into mechanisms underlying the persistence of the partial kindling effect, we suspended amygdaloid kindling at different seizure stages in rats, and investigated the effects on subsequent rekindling after a rest period of 2 months. Ten-week-old rats, implanted with bipolar electrodes, were separated by various initial kindling stages into 5 groups of rats, partially kindled to stages 1 (n = 7) and 2 (n = 10), fully kindled to stages 4 (n = 11) and 5 (n = 11), and control rats (n = 12) which were implanted but not stimulated initially. The number of stimulations required to elicit the first stage 5 seizure during rekindling was significantly lower in the fully kindled groups (P < 0.01 in the stage 4 group and P < 0.001 in the stage 5 group) than the control group. The cumulative afterdischarge duration during rekindling was significantly shorter in the fully kindled groups (P < 0.01 in both groups) than the control group. The latency of the first stage 5 seizure during rekindling was significantly shorter in the partially and fully kindled groups than the control group. These results suggest that epileptogenesis acquired at the partially kindled stage is different than that acquired at the fully kindled stage. However, the effects of the initial kindling on the latency to produce the stage 5 seizure during rekindling persisted both in the partially and fully kindled rats

A study on intraalveolar exudates in acute mycoplasma pneumoniae infection.

Pathologic features of Mycoplasma pneumoniae infection (M. pneumonia) are generally non-specific, and the literature regarding the pathologic features of M. pneumonia with intraalveolar exudates is limited. Clinical and histopathological studies were performed in 3 patients with M. pneumonia which did not respond to erythromycin and minocycline, but all rapidly recovered after corticosteroid therapy. In pathologic findings, we observed intraalveolar exudates and focal organization in M. pneumonia, and its intraalveolar lesions were compared between M. pneumonia and bronchiolitis obliterans organizing pneumonia containing fibrin (BOOP). Immunohistochemical studies were performed using the streptavidin biotin peroxidase complex method with anti-alpha-smooth muscle actin antibody and anti-pancytokeratin AE1/AE3 antibody. In pathologic findings, more fibrin deposits in intaalveolar lesions were observed in M. pneumonia than in BOOP. In intaalveolar lesions of M. pneumonia, a larger amount of nuclear debris, more neutrophils, and more erythrocytes were noted. Myofibroblasts were observed in the organization of BOOP, while in the intaalveolar lesions of M. pneumonia, myofibroblasts were not observed. These results suggest that M. pneumonia with intraalveolar exudates responds well to corticosteroid and its intraalveolar lesions apparently differed from those in BOOP.</p

Current state of therapeutic development for rare cancers in Japan, and proposals for improvement

This article discusses current obstacles to the rapid development of safe and effective treatments for rare cancers, and considers measures required to overcome these challenges. In order to develop novel clinical options for rare cancers, which tend to remain left out of novel therapeutic development because of their paucity, efficient recruitment of eligible patients, who tend to be widely dispersed across the country and treated at different centers, is necessary. For this purpose, it is important to establish rare cancer registries that are linked with clinical studies, to organize a central pathological diagnosis system and biobanks for rare cancers, and to consolidate patients with rare cancers to facilities that can conduct clinical studies meeting international standards. Establishing an all‐Japan cooperative network is essential. Clinical studies of rare cancers have considerable limitations in study design and sample size as a result of paucity of eligible patients and, as a result, the level of confirmation of the efficacy and safety shown by the studies is relatively low. Therefore, measures to alleviate these weaknesses inherent to external conditions need to be explored. It is also important to reform the current research environment in order to develop world‐leading treatment for rare cancers, including promotion of basic research, collaboration between industry and academia, and improvement of the infrastructure for clinical studies. Collaboration among a wide range of stakeholders is required to promote the clinical development of treatment for rare cancers under a nationwide consensus