Pulmonary involvement in Crohn's disease

Pulmonary Crohn's Disease or Crohn's Disease with Lung Sarcoidosis? A Case Report and Literature Review

BACKGROUND

Crohn's disease and ulcerative hemorrhagic colitis are forms of granulomatous inflammatory intestinal disease, which usually affects the gastrointestinal tract. There are also reported rare localizations at the skin, kidney, joints, liver and eye level. Pulmonary involvement is relatively rare, and it is most commonly reported in suppuration with bronchiectasis. On the other hand, sarcoidosis is, in principle, a thoracic localization of a granulomatosis disease, although bowel, skin and intestinal disorders are described. There is not a clear line to separate Crohn's disease from sarcoidosis with, possibly because they are, in fact, considered to have the same inflammatory granulomatosis disease pathology. The diagnoses of the two entities, sarcoidosis and Crohn's disease, are based on non-pathognomonic, inclusive clinical and paraclinical criteria, without elements of the mutual exclusion of typical locations.

CASE REPORT

We present a very rare case of a young male, already diagnosed with small-bowel Crohn's disease. Granulomatous lung disease with major hemoptysis requires emergency surgery. An intraoperative assessment revealed a necrotic hemorrhagic lesion located in the left lower lobe and a lobectomy was performed. The final pathological report showed the presence of non-caseous granulomatous inflammation, with the identification of specific multinucleated giant cells.

CONCLUSIONS

The identical diagnostic principles of Crohn's disease and sarcoidosis, Crohn's disease as a predecessor to pulmonary lesions, the clinical picture and the necrotico-hemorrhagic appearance of the unilateral pulmonary lesion, which are similar to aggressive necrotico-hemorrhagic or perforating intestinal forms, are arguments in favor of the diagnosis of pulmonary Crohn's disease and not pulmonary sarcoidosis. At the same time, in general, the two diseases have overlapping elements, suggesting they are, in fact, not the same disease with different facets.

Inborn Errors in the LRR Domain of Nod2 and Their Potential Consequences on the Function of the Receptor

The innate immune system plays a critical role in the early detection of pathogens, primarily by relying on pattern-recognition receptor (PRR) signaling molecules. Nucleotide-binding oligomerization domain 2 (NOD2) is a cytoplasmic receptor that recognizes invading molecules and danger signals inside the cells. Recent studies highlight the importance of NOD2′s function in maintaining the homeostasis of human body microbiota and innate immune responses, including induction of proinflammatory cytokines, regulation of autophagy, modulation of endoplasmic reticulum (ER) stress, etc. In addition, there is extensive cross-talk between NOD2 and the Toll-like receptors that are so important in the induction and tuning of adaptive immunity. Polymorphisms of NOD2′s encoding gene are associated with several pathological conditions, highlighting NOD2′s functional importance. In this study, we summarize NOD2′s role in cellular signaling pathways and take a look at the possible consequences of common NOD2 polymorphisms on the structure and function of this receptor.