- Among asymptomatic Diamond Princess cruise passengers who tested positive for SARS-CoV-2, those with higher serum lactate dehydrogenase (LDH) levels were likelier to transition to symptomatic COVID-19, according to findings published in Lancet Infectious Disease.
- A separate report in NEJM, also covering Diamond Princess cruise passengers, found that some patients who are asymptomatic at testing may really be presymptomatic, a likelihood that increases with age.
Why this matters
- High LDH levels may signal risk of transitioning to symptomatic status.
- Age is a risk factor for transitioning to becoming symptomatic.
- Lancet Infectious Disease: retrospective analysis, 104 cruise passengers testing positive for SARS-CoV-2 and hospitalized for observation in Japan.
- NEJM letter: analysis of 96 passengers who were asymptomatic when testing positive for SARS-CoV-2, also hospitalized for observation.
- Funding: None.
- Lancet Infectious Disease study:
- 104 participants; median age, 68 (interquartile range [IQR], 47-75) years; 52% (54) male.
- At admission, 41% (43) were asymptomatic, and 39% (41) had mild COVID-19.
- 23% (10/43) asymptomatic patients developed symptomatic COVID-19.
- Increased LDH concentrations were more common in those who transitioned to being symptomatic: OR, 7.25 (P=.020).
- Overall, 10% (8/84) with asymptomatic or mild COVID-19 progressed to severe illness.
- NJEM report:
- 11/96 asymptomatic patients developed symptoms at a median of 4 (IQR, 3-5) days after a positive SARS-CoV-2 test, and thus were really presymptomatic.
- Age was associated with being presymptomatic:
- OR per year increase in age: 1.08 (95% CI, 1.01-1.16).
- Selection bias.
- Small samples.