Case 2
A 5-month-old girl developed five days before admission high fever,
pallor, irritability, nausea, vomiting, diarrhea and a perianal
dermatosis. Clinically she was lethargic, dehydrated, with generalized
pallor, tachypnea and bilateral rales, cervical, axillar and inguinal
lymphadenopathies, hepatosplenomegaly and week peripheral pulses.
Laboratory tests showed WBC 14,930/mm3 (PMN 5%,
lymphocytes 55%, monocytes 40%), Hb 3.7g/dL, platelet count
8,000/mm3, albumin 2.3 g/dL, total bilirubin 1.1
mg/dL, CRP 37.1mg/dL, procalcitonin 11 ng/mL, ferritin 2,290 ng/mL and
fibrinogen 398 mg/dL. Treatment was initiated with cefotaxime and
vancomycin, a chest CT was performed with findings suggestive of
COVID-19 infection, with interstitial infiltrates, ground-glass
opacities bronchoalveolar thickening and left subsegmental atelectasis
(Fig 1B). Laboratory tests showed a D-dimer 6.52 µg/mL, NT-proBNP 207
pg/mL, Troponin I <10 pg/ with positive immunoglobulin IgG
serology and negative RT-PCR for SARS-CoV-2; the echocardiogram reported
LVEF 48%. The diagnosis of MIS-C was made and received treatment with
IVIG (2g/kg), three boluses of methylprednisolone (30 mg/kg/dose) and
enoxaparin (1 mg/kg/dose).
She had persistent fever, bicytopenia with anemia and thrombocytopenia,
albumin 2.9g/dL, total bilirubin 0.67 mg/dL, CRP 1.6 mg/dL,
procalcitonin 0.53 ng/mL, D-dimer 6.14 mcg/mL, ferritin 1000 ng/mL,
NT-proBNP 428 pg/mL triglycerides 531 mg/dL, fibrinogen 159 mg/dL, IL-6
levels in 4.52 pg/mL (<9.7); she developed multi-organ failure
despite treatment and had significant hepatosplenomegaly. A bone marrow
aspiration was performed with hemophagocytosis (Figure 3); HScore was
224. A second dose of IVIG was administrated and had induction treatment
according to HLH 2004 Protocol with low dose etoposide and
dexamethasone. Blood cultures grew Serratia marcescens was
treated with meropenem. Clinical improvement was seen after 72 hours and
the patient had a favorable response after six weeks of chemotherapy
with normalization of CBC; follow-up, all medications were stopped and a
new bone marrow biopsy showed normal findings (Figure 3C). Primary
Hemophagocytic lymphohistiocytosis (HLH) was ruled out with
next-generation sequencing.