To describe 2 cases of autoimmune neutropenia (AIN) patients infected with Sars-Cov-2.

Two subjects case report.

Case report 1: A girl with primary AIN since 1 year and 10 months old, maintaining severe neutropenia and mild recurrent infections. Presented to the emergency department in June/2020, at 3 years and 8 months old, with flu-like symptoms, afebrile, in good general condition. Physical examination was normal. The absolute neutrophil count (ANC) was 0.279 × 109/L. At hospital admission, Sars-Cov-2 (RT-PCR) tested positive and filgrastim (G-CSF) 5 μg/kg/day was initiated. Chest X-ray was also normal and blood culture resulted negative. She remained in great general condition, afebrile, and was discharged on the 2nd day of hospitalization, with clarithromycin (15 mg/kg/day). After G-CSF, ANC: 0.494 × 109/L (1st dose), 1.431 × 109/L (2nd dose). On outpatient follow-up, she had no long-term complications from Covid-19. Case Report 2: A man with chronic immune thrombocytopenia purpura (ITP) since 2008, autoimmune hemolytic anemia since 2013, evolved with AIN on May/2020, at 42 years old, with ANC lower than 0.5 × 109/L. On 6/1/2020, he had ANC 0.170 × 109/L. On 6/25/2020, he started flu-like symptoms, had ANC of 5.118 × 109/L, and tested positive for Sars-Cov-2 (RT-PCR). He kept high fever (102,2°F) and was hospitalized for 10 days without use of G-CSF. After discharge, on outpatient follow-up, he had no long-term complications from Covid-19, and presented ANC 0.338 × 109/L (Aug/2020).

At beginning of Covid-19 pandemic, severity infection in children was unknown. Today is known that most of them have milder clinical course, regardless of chronic diseases. In adults, in contrast, the inflammatory response tends to exacerbation, with more severe clinical conditions. Furthermore, many case reports of patients infected by SARS-CoV-2 with comorbidities literature are published. However, to date there are no reports on the impact of COVID-19 in AIN patients. Increased neutrophil counts during infectious episodes are common in AIN, which appears to be related to the benign course of most infections. We reported 2 cases of AIN patients diagnosed with Covid-19, both with favorable clinical outcomes despite heterogenic clinical course. On the first case, she presented few symptoms and ANC increased only after using G-CSF. On the second reported patient, there was a spontaneous increase of ANC and greater inflammatory response than the first case. It could suggest a correlation between inflammatory response to COVID-19 and ANC in cases of autoimmune neutropenia.

In the reported cases, clinical course of disease and neutrophil count were different between adult and pediatric patients. It is not possible to state whether this difference is due to age group, individual response to infection or other variables. It is important to assess other cases of AIN infected by COVID 19 to better understand correlation between severity of infection and neutrophil count response.