Therapeutic effect of mizoribine on pemphigus vulgaris and pemphigus foliaceus

Clinical course and outcomes of pemphigus vulgaris and foliaceus: A retrospective study using a nationwide database in Japan

Pemphigus is a life-threatening autoimmune blistering disease. Patient characteristics, treatment courses, and outcomes remain unclear owing to its rarity. To describe the background, treatment, and outcomes of pemphigus, we identified 2598 patients with pemphigus vulgaris and 1186 patients with pemphigus foliaceus from a nationwide inpatient database in Japan. Patients with pemphigus vulgaris were younger (62 vs 72 years, P < 0.001), had fewer comorbidities, and were more likely to be admitted to high-volume hospitals (38% vs 30%, P < 0.001) than those with pemphigus foliaceus. Patients with pemphigus vulgaris had undergone more aggressive treatment, including steroid pulse therapy, intravenous immunoglobulin, or plasmapheresis, compared with those with pemphigus foliaceus (48% vs 42%, P = 0.001); specifically, in patients aged <70 years, the pemphigus vulgaris group was more likely to undergo aggressive treatment than the pemphigus foliaceus group (52% vs 45%), whereas there was no significant difference in patients aged ≥70 years (40% vs 40%). Immunosuppressive agents (30% vs 26%, P = 0.015) and analgesics, including opioids (45% vs 36%, P < 0.001), were used more frequently, whereas topical corticosteroids were used less frequently (32% vs 48%, P < 0.001) in patients with pemphigus vulgaris compared with those with pemphigus foliaceus. In-hospital mortality was lower in patients with pemphigus vulgaris than in those with pemphigus foliaceus (2.2% vs 4.0%, P = 0.002); in the comparison stratified by age, the mortality was equivalent among the two groups (0.6% in patients aged <70 years and 6.1% in those aged ≥70 years). Overall, patients with pemphigus vulgaris had a 10-day longer hospitalization period and higher hospitalization costs than those with pemphigus foliaceus. Our findings provide useful information for understanding the current trends in the management of pemphigus in Japan.

Anti-Tumor Potential of IMP Dehydrogenase Inhibitors: A Century-Long Story

The purine nucleotides ATP and GTP are essential precursors to DNA and RNA synthesis and fundamental for energy metabolism. Although de novo purine nucleotide biosynthesis is increased in highly proliferating cells, such as malignant tumors, it is not clear if this is merely a secondary manifestation of increased cell proliferation. Suggestive of a direct causative effect includes evidence that, in some cancer types, the rate-limiting enzyme in de novo GTP biosynthesis, inosine monophosphate dehydrogenase (IMPDH), is upregulated and that the IMPDH inhibitor, mycophenolic acid (MPA), possesses anti-tumor activity. However, historically, enthusiasm for employing IMPDH inhibitors in cancer treatment has been mitigated by their adverse effects at high treatment doses and variable response. Recent advances in our understanding of the mechanistic role of IMPDH in tumorigenesis and cancer progression, as well as the development of IMPDH inhibitors with selective actions on GTP synthesis, have prompted a reappraisal of targeting this enzyme for anti-cancer treatment. In this review, we summarize the history of IMPDH inhibitors, the development of new inhibitors as anti-cancer drugs, and future directions and strategies to overcome existing challenges.