According to a case study reported in the Lancet Haematology, clinical and biochemical data of COVID-19 might be partly masked by coexisting chronic lymphocytic leukaemia or compromised immunity.
A 39-year-old male with chronic lymphocytic leukaemia presented to hospital with a four-day history of fever, sore throat, productive cough and dyspnoea. Blood parameters were; a white blood cell count of 91·85 × 109 cells/L, lymphocytes 96%, haemoglobin 85 g/L, platelet count of 79 × 109 cells/L. A chest CT scan showed bilateral ground-glass opacities indicative of COVID-19.
He was treated with oral chlorambucil, nebulised α-interferon, intravenous human immunoglobulin, and intravenous methylprednisolone, and received non-invasive ventilation therapy until dyspnoea subsided (day 8). A follow-up chest CT showed substantial improvement. A repeat COVID-19 test remained positive.
Without the complete travel history, COVID-19 infection was not initially suspected, because his whole blood cell and lymphocyte counts were high. This was due to his chronic lymphocytic leukaemia masking a potential infection. This case is interesting because the estimated incubation period for COVID-19 infection is thought to be no more than 14 days. However, a retrospective review of the patient's condition suggested an incubation period of about 25 days.
Individuals with compromised immune status might be subjected to a longer incubation period.