Acute Effects on the Human Peripheral Blood Transcriptome of Decompression Sickness Secondary to Scuba Diving

Abstract

Decompression sickness (DCS) develops due to inert gas bubble formation in bodily tissues and in the circulation, leading to a wide range of potentially serious clinical manifestations. Its pathophysiology remains incompletely understood. In this study, we aim to explore changes in the human leukocyte transcriptome in divers with DCS compared to closely matched unaffected controls after uneventful diving. Cases (n = 7) were divers developing the typical cutis marmorata rash after diving with a confirmed clinical diagnosis of DCS. Controls (n = 6) were healthy divers who surfaced from a ≥25 msw dive without decompression violation or evidence of DCS. Blood was sampled at two separate time points—within 8 h of dive completion and 40–44 h later. Transcriptome analysis by RNA-Sequencing followed by bioinformatic analysis was carried out to identify differentially expressed genes and relate their function to biological pathways. In DCS cases, we identified enrichment of transcripts involved in acute inflammation, activation of innate immunity and free radical scavenging pathways, with specific upregulation of transcripts related to neutrophil function and degranulation. DCS-induced transcriptomic events were reversed at the second time point following exposure to hyperbaric oxygen. The observed changes are consistent with findings from animal models of DCS and highlight a continuum between the responses elicited by uneventful diving and diving complicated by DCS. This study sheds light on the inflammatory pathophysiology of DCS and the associated immune response. Such data may potentially be valuable in the search for novel treatments targeting this disease.

Varying Oxygen Partial Pressure Elicits Blood-Borne Microparticles Expressing Different Cell-Specific Proteins—Toward a Targeted Use of Oxygen?

“…While the role of MPs in decompression stress is not clear, they seem to play a major role as VGE precursors or as a mediator of inflammation [ 62 ]. To the best of our knowledge, this is the first study describing blood-borne MP responses to different PO 2 .…”

The management of patent foramen ovale in divers: where do we stand?

“…Transcriptome analysis of divers with DCS could also help to the better comprehension of this disease. 57 Regarding the role of PFO closure for secondary prevention of DCI, no randomized controlled study has compared the invasive versus conventional management. In addition, more studies about the risk stratification of divers with PFO should be conducted.…”

“…Transcriptome analysis of divers with DCS could also help to the better comprehension of this disease. 57 Regarding the role of…”

Dissolved gases from pressure changes in the lungs elicit an immune response in human peripheral blood

“…While both in vitro and in vivo models have been used to assess immune responses to pressure changes and nucleated bubbles, they fail to account for the role of dissolved gases in a physiologically relevant manner. 27–29 Thus, we report a model that recapitulates the physiology of the human lungs during compression and decompression using human lung-on-a-chip devices. These devices mimic gas permeation through the alveolar epithelium due to elevated hydrostatic pressures, gas dissolution in whole blood, and interactions between circulating blood and the vascular endothelium (Table 1).…”