Case Description
We present a previously healthy 11-year-old male presented with fevers, dizziness, loss of appetite and new onset petechial rash on his lower legs with prolonged epistaxis of one-week duration. The family history was notable for his mother having died due to lupus nephritis. Both his father and paternal grandfather were symptomatically positive for COVID-19 infection three weeks prior to his presentation. Initial laboratory tests were remarkable for anemia and thrombocytopenia. [Table 1] A review of the peripheral blood smear shown in Figure 1 A. He also exhibited marked abnormalities in hemolysis markers. [Table 1] Direct antiglobulin (DAT) was positive with normal immune globulins. [Table 1]
A nasopharyngeal swab showed he was COVID-19 positive by RT-PCR, with elevated SARS-COV-2 IgG antibodies. Inflammatory markers and cytokines were normal. [Table 1] His troponin I and Brain natrutic peptide were both highly elevated. [Table 1] A 2D-echocardiogram was obtained which was significant for ectasia of left main coronary artery (LMCA) with uniform dilation with a moderately decreased left ventricular (LV) function.
We therefore suspected him to have MIS-C with likely TTP or Evan’s syndrome. Due to the family history of SLE and hematuria and proteinuria on presentation, we investigated for an underlying rheumatologic disease. The resultant laboratory tests revealed strong positive SLE serology [Table 1]
Patient was given Intravenous immune globulin (IVIG) for the treatment of Evan’s syndrome and followed by pulse methylprednisolone. After 48hrs following IVIG and methylprednisolone with no clinical or laboratory improvement and also with new neurological symptoms of drowsiness and headache as well as right upper quadrant (RUQ) pain, we increasingly considered TTP. Low ADAMTS13 activity and a high inhibitor titer confirmed the diagnosis. Thereafter patient was immediately started on plasma exchange (PE), and promptly exhibited an impressive clinical improvement in under 24 hours. Following 7 sessions of PE, his platelets count normalized and anemia gradually improved with complete resolution of hemolysis markers, proteinuria and hematuria. [Table 1] and [Figure 1B] A repeat DAT following PE was negative. His echocardiogram also showed normalization of his LV size and function, resolution of LMCA dilation and now dilation of the right coronary artery without evidence of aneurysm for which he was started on low dose aspirin. Patient was transitioned to prednisone and started on mycophenoloate mofetil and hydroxychloroquine sulfate for SLE control. Genetic testing was negative for inherited TTP.