CD4 T-Cell Subsets and the Pathophysiology of Inflammatory Bowel Disease.

Inflammatory bowel disease (IBD) is an umbrella term for the chronic immune-mediated idiopathic inflammation of the gastrointestinal tract, manifesting as Crohn's disease (CD) or ulcerative colitis (UC). IBD is characterized by exacerbated innate and adaptive immunity in the gut in association with microbiota dysbiosis and the disruption of the intestinal barrier, resulting in increased bacterial exposure. In response to signals from microorganisms and damaged tissue, innate immune cells produce inflammatory cytokines and factors that stimulate T and B cells of the adaptive immune system, and a prominent characteristic of IBD patients is the accumulation of inflammatory T-cells and their proinflammatory-associated cytokines in intestinal tissue. Upon antigen recognition and activation, CD4 T-cells differentiate towards a range of distinct phenotypes: T helper(h)1, Th2, Th9, Th17, Th22, T follicular helper (Tfh), and several types of T-regulatory cells (Treg). T-cells are generated according to and adapt to microenvironmental conditions and participate in a complex network of interactions among other immune cells that modulate the further progression of IBD. This review examines the role of the CD4 T-cells most relevant to IBD, highlighting how these cells adapt to the environment and interact with other cell populations to promote or inhibit the development of IBD.

Pathophysiology of Inflammatory Bowel Disease: Innate Immune System.

Inflammatory bowel disease (IBD), comprising Crohn's disease (CD) and ulcerative colitis (UC), is a heterogeneous state of chronic intestinal inflammation with no exact known cause. Intestinal innate immunity is enacted by neutrophils, monocytes, macrophages, and dendritic cells (DCs), and innate lymphoid cells and NK cells, characterized by their capacity to produce a rapid and nonspecific reaction as a first-line response. Innate immune cells (IIC) defend against pathogens and excessive entry of intestinal microorganisms, while preserving immune tolerance to resident intestinal microbiota. Changes to this equilibrium are linked to intestinal inflammation in the gut and IBD. IICs mediate host defense responses, inflammation, and tissue healing by producing cytokines and chemokines, activating the complement cascade and phagocytosis, or presenting antigens to activate the adaptive immune response. IICs exert important functions that promote or ameliorate the cellular and molecular mechanisms that underlie and sustain IBD. A comprehensive understanding of the mechanisms underlying these clinical manifestations will be important for developing therapies targeting the innate immune system in IBD patients. This review examines the complex roles of and interactions among IICs, and their interactions with other immune and non-immune cells in homeostasis and pathological conditions.

[Pallister-Killian syndrome. Case report]. / Síndrome de Pallister-Killian. Comunicación de un caso.

BACKGROUND: Pallister-Killian syndrome is a rare sporadic genetic disorder with a tissue-specific mosaic distribution of an additional isochromosome 12p [i(12p)]. Due to the low risk of recurrence, prenatal diagnosis of this syndrome is important for the genetic counseling. OBJECTIVE: To report the first prenatal diagnosis case of Pallister-Killian syndrome in Mexico (lethal neonatal presentation associated with hypoplastic left heart). METHODS/RESULTS: We admitted to our hospital a third-trimester, 31-year-old-pregnant woman; the level II sonographic examination showed: polyhydramnios, micromelia, hypoplastic left heart and a fetal facial profile characterized by small nose, thin upper lip and protruding lower lip. We confirmed the diagnosis with cultured amniotic cells. Standard G banding techniques showed a male karyotype with an extra chromosome i(12p) in the 100% of metaphase cells: 47,XY, + i(12p).

[Intrauterine necrosis in closed gastroschisis]. / Necrosis intestinal in utero por gastrosquisis.

INTRODUCTION: Strangulation of the intestine as the result of compression of its blood supply in a tightly closed gastroschisis defect is a very rare occurrence. CLINICAL CASES: We present the cases of two newborn patients who had extra-abdominal infarcted bowel and intra-abdominal jejunal atresia due to vascular compression for gastroschisis defect. One was associated with colonic, probably acquired aganglionosis. Both had similar clinical courses. CONCLUSIONS: This association is very uncommon. Prognosis of this complex is very poor.