A Curious Case of Autoimmunity, Pancytopenia, and Disseminated Intravascular Coagulation.

HISTORY AND EXAMINATION: A 21-year-old female patient presented to us with severe low back pain for 4 months. On examination, patient was afebrile, with severe pallor, and tenderness in both sacroiliac (SI) joints. Patient was being admitted and evaluated, and during the course of evaluation, developed severe headache, which was severe in intensity and associated with nausea and projectile vomiting. Initial investigations: An X-ray of the bilateral SI joints revealed inflammation, and the antinuclear antibody (ANA) turned out to be 4+ with pancytopenia and raised lactate dehydrogenase (LDH), but the liver function tests were normal. Rest of the rheumatological profile was unremarkable. During the course of the evaluation, she developed a severe headache, which, on imaging, showed presence of cerebral edema with chronic subdural hematoma, and a concomitant coagulopathy workup revealed evidence of disseminated intravascular coagulation (DIC). DISCUSSION: Taking the whole picture into consideration, a malignant process in the body was suspected, and serum tumor markers carcinoembryonic antigen (CEA), carbohydrate antigen 19-9 (CA19-9), and cancer antigen 125 (CA-125) were sent, all of which were raised. Validating the clinical clue was the bone marrow biopsy done for pancytopenia, which revealed malignant epithelial infiltration. A contrast-enhanced computed tomography (CECT) thorax and whole abdomen were done to find out the primary, which showed a neoplastic mass at the gastroesophageal junction along with bony metastases in the vertebrae and left adrenal. Tissue from the primary lesion was taken for histopathological examination (HPE) through upper gastrointestinal endoscopy. Although HPE revealed grade III poorly differentiated stomach adenocarcinoma, the patient had succumbed to the disease process by the time the diagnosis came to light. CONCLUSION: In short, this case perfectly illustrates how solid organ malignancies might be a mimicker of multisystem disorders, thereby delaying diagnosis and worsening the prognosis even further.

Endoplasmic reticulum stress impedes regulated secretion by governing key exocytotic and granulogenic molecular switches.

Dense core vesicles (DCVs) and synaptic vesicles are specialised secretory vesicles in neurons and neuroendocrine cells, and abnormal release of their cargo is associated with various pathophysiologies. Endoplasmic reticulum (ER) stress and inter-organellar communication are also associated with disease biology. To investigate the functional status of regulated exocytosis arising from the crosstalk of a stressed ER and DCVs, ER stress was modelled in PC12 neuroendocrine cells using thapsigargin. DCV exocytosis was severely compromised in ER-stressed PC12 cells and was reversed to varying magnitudes by ER stress attenuators. Experiments with tunicamycin, an independent ER stressor, yielded similar results. Concurrently, ER stress also caused impaired DCV exocytosis in insulin-secreting INS-1 cells. Molecular analysis revealed blunted SNAP25 expression, potentially attributed to augmented levels of ATF4, an inhibitor of CREB that binds to the CREB-binding site. The effects of loss of function of ATF4 in ER-stressed cells substantiated this attribution. Our studies revealed severe defects in DCV exocytosis in ER-stressed cells for the first time, mediated by reduced levels of key exocytotic and granulogenic switches regulated via the eIF2α (EIF2A)-ATF4 axis.