Deep phenotyping of post-infectious myalgic encephalomyelitis/chronic fatigue syndrome.

Post-infectious myalgic encephalomyelitis/chronic fatigue syndrome (PI-ME/CFS) is a disabling disorder, yet the clinical phenotype is poorly defined, the pathophysiology is unknown, and no disease-modifying treatments are available. We used rigorous criteria to recruit PI-ME/CFS participants with matched controls to conduct deep phenotyping. Among the many physical and cognitive complaints, one defining feature of PI-ME/CFS was an alteration of effort preference, rather than physical or central fatigue, due to dysfunction of integrative brain regions potentially associated with central catechol pathway dysregulation, with consequences on autonomic functioning and physical conditioning. Immune profiling suggested chronic antigenic stimulation with increase in naïve and decrease in switched memory B-cells. Alterations in gene expression profiles of peripheral blood mononuclear cells and metabolic pathways were consistent with cellular phenotypic studies and demonstrated differences according to sex. Together these clinical abnormalities and biomarker differences provide unique insight into the underlying pathophysiology of PI-ME/CFS, which may guide future intervention.

A case of spontaneous tumor lysis syndrome in an adolescent with abdominal pain.

Tumor lysis syndrome (TLS) is an acutely life threatening, must-not miss, oncological emergency that infrequently presents to the emergency department (ED). This diagnosis is typically a complication of chemotherapy, however, TLS can also occur spontaneously as the first presentation of malignancy. This case discusses the rare presentation of an otherwise healthy adolescent male who presented to the ED with abdominal pain and lethargy and was subsequently found to be in acute renal failure and pancytopenic with the associated lab derangements of hyperkalemia, hyperphosphatemia, and hypocalcemia. Subsequent investigation revealed profound hyperuricemia, from which the presumptive diagnosis of spontaneous TLS was made. Further workup revealed the diagnosis of pre-B cell acute lymphoblastic leukemia. This case emphasizes the consideration of TLS as a cause of acute renal failure or severe electrolyte derangements in those who may not have a known diagnosis of malignancy or recent chemotherapy.