Ulcerative colitis masked by giant urticaria

Common autoimmune diseases and urticaria: the causal relationship from a bidirectional two-sample mendelian randomization study

Objective

The immune response assumes a pivotal role in the underlying mechanisms of urticaria pathogenesis. The present study delves into an investigation of the genetic causal connections between urticaria and prevalent autoimmune afflictions, notably rheumatoid arthritis (RA), systemic lupus erythematosus (SLE), ulcerative colitis (UC), and Crohn's disease (CD).

Methods

A bidirectional two-sample Mendelian randomization (MR) analysis was conducted to investigate the causal relationships involving four autoimmune diseases and urticaria. The genome-wide association study (GWAS) summary data of four autoimmune disease were sourced from the IEU OpenGWAS database. The GWAS summary data for urticaria were derived from the Finnish consortium dataset. The principal analytical approach employed in this study was the random-effects inverse variance weighted (IVW) method. Subsequently, a series of sensitivity analyses were performed, encompassing assessments of heterogeneity, horizontal pleiotropy, outliers, "Leave-one-out" analyses, and tests for adherence to the assumption of normal distribution.

Results

The random-effects IVW analysis indicate a positive genetic causal association between RA and urticaria (P < 0.001, OR 95% CI = 1.091 [1.051-1.133]). Conversely, SLE, UC, and CD do not exhibit a significant genetic causal relationship with urticaria. The reverse MR analysis reveals a positive genetic causal linkage between urticaria and SLE (P = 0.026, OR 95% CI = 1.289 [1.031-1.612]). However, the analysis demonstrates no substantial genetic causal relationship between urticaria and RA, UC, or CD. Importantly, the genetic causal assessment absence of heterogeneity, horizontal pleiotropy, and outliers. Furthermore, it remains unaffected by any individual single nucleotide polymorphism (SNP), demonstrating adherence to a normal distribution.

Conclusion

This investigation establishing RA as a predisposing factor for urticaria. Moreover, urticaria as a plausible risk determinant for SLE. Heightened vigilance is recommended among RA patients to monitor the manifestation of urticaria within clinical settings. Similarly, individuals afflicted by urticaria should duly acknowledge the prospective susceptibility to SLE.

Chronic urticaria as a presenting symptom of Crohn's disease

Clinical presentation of Crohn's disease (CD) may be variable according to the location and the intensity of the inflammation. Some patients may have atypical symptoms which could delay the diagnosis. We report the first case of chronic urticaria related to a subclinical, complicated CD. Although the pathologic mechanism of this association was unclear in our patient, this case suggests that in patients with unexplained chronic urticaria it is opportune to investigate for a possible CD, even if there are no or few specific symptoms of intestinal inflammatory disease.

Chronic urticaria as a presenting symptom of Crohn's disease

Clinical presentation of Crohn's disease (CD) may be variable according to the location and the intensity of the inflammation. Some patients may have atypical symptoms which could delay the diagnosis. We report the first case of chronic urticaria related to a subclinical, complicated CD. Although the pathologic mechanism of this association was unclear in our patient, this case suggests that in patients with unexplained chronic urticaria it is opportune to investigate for a possible CD, even if there are no or few specific symptoms of intestinal inflammatory disease.

Impact of Porcine Orexin a on Glucagon Plasma Concentrations in Pigs

In 1998, Orexin A was added to the long list of orexigenic neuropeptides of the brain's physiology. Orexin A is involved in the central control of appetite and in energy homeostasis, as well as in the regulation of many other physiological functions. It is produced by a small cluster of the brain's neurons, located mainly in and around the lateral hypothalamic area. This site is known to be involved in regulating feeding in mammals. An intracerebroventricular injection of Orexin A into the rat's brain causes an impressive increase in the consumption of food, while an intravenous injection induces changes on glucagon plasma concentrations in rats. In addition, there are signs of changes on glucagon plasma concentrations when Orexin A acts on individual pancreatic islets of rats. In this study, we investigated the potential effects of the central administration of porcine Orexin A on glucagon plasma concentrations in pigs, and examined whether these changes are associated with the possible effect of the neuropeptide on the enteroinsular axis.