NPPB and lymphopenia: Paraclinically, both long-term COVID-19 syndrome and MIS are characterized by elevated C-reactive protein, ESR, fibrinogen, ferritin, procalcitonic, leukocytosis or lymphopenia, and increased NT-proBNP, while leukopenia with lymphopenia was the most common change reported in patients with MIS-C [15,22,71].