Discussion
40 patients followed in our onco-hematology department (Strasbourg University Hospital) were tested by SARS-CoV-2 RT-PCR since March 1, 2020, with six being positive. All of them were asymptomatic or presented a mild disease and none of them needed a specific treatment and/or being hospitalized. The patient we report about is the most immunosuppressed of our infected patients being an HSCT recipient and the only one presenting pulmonary lesions on chest CT scan. Despite being at high potential risk of a severe form of COVID-19 due to the post-allograft immunosuppression, mild dilated cardiomyopathy, GVHD, corticosteroids therapy, severe lymphopenia and despite the pulmonary images found on chest CT scan the patient we report only presented a rhinitis.
There are now several studies describing the kinetics of anti-SARS-CoV-2 IgM and IgG detection, most reporting that IgM are detectable as soon as 5-14 days after first clinical symptoms10,11. However, symptom severity may also affect the rate of seropositivity. A delayed or absent humoral response against SARS-CoV-2 has been reported in some patients 12 and may result in negative serology results13. Surprisingly, despite her immunosuppressed condition and her mild symptoms she developed an immune response with IgM produced at D14 which is consistent with what can be found in the literature for immunocompetent patients 14. IgG only appeared at day 56. Furthermore, the virus was said to remain detectable for up to three weeks 15, but our patient still had a weak positive RT-PCR after 42 days.
Very few data is available on children with cancer but it seems that in this fragile population COVID-19 is largely pauci-symptomatic. In any event, clinical management in this population is a challenge for the clinician because oncologic treatment is essential and cannot be postponed. It creates a number of difficulties regarding the follow-up organization of those infected patients needing weekly consultations.