From Pancytopenia to Hyperleukocytosis, an Unexpected Presentation of Immune Reconstitution Inflammatory Syndrome in an Infant with Methylmalonic Acidemia

Bibliographic Data

ID15713628
AuthorsSamuel Sassine (0000-0002-6175-7547, Université de Montréal), Amandine Remy (Centre Hospitalier Universitaire Sainte-Justine), Tanguy Demaret (0000-0001-7605-9031, Université de Montréal), François Proulx (0000-0002-9473-0834, Centre Hospitalier Universitaire Sainte-Justine), Julie Autmizguine (0000-0001-8975-5052, Centre Hospitalier Universitaire Sainte-Justine), Fatima Kakkar (0000-0001-7408-4399, Université de Montréal), Thai Hoa Tran (0000-0002-8712-6233, Université de Montréal), Caroline Laverdière (0000-0002-4917-7152, Centre Hospitalier Universitaire Sainte-Justine), Ellery T Cunan (McGill University), Catalina Maftei (Université de Montréal), Grant A Mitchell (0009-0003-0083-1453, Centre Hospitalier Universitaire Sainte-Justine), Grant Mitchell (CHU Sainte-Justine Research Center, Montreal, QC H3T 1C5, Canada), Hélène Decaluwe (0000-0001-6617-0633, Université de Montréal), Jade Hindié (Université de Montréal, corresponding author)
Year2024
Volume11
Issue8
Pages990-990
Publication date2024-08-14
Peer ReviewedYes
Open AccessYes
TypeARTICLE
VenueChildren (JOURNAL)
Journal identifiersISSN: 2227-9067 • E-ISSN: 2227-9067
PublisherMultidisciplinary Digital Publishing Institute (PUBLISHER • CH)
DOI10.3390/children11080990
PMID39201925
OpenAlexW4401576629
LanguageEN
References cited26

A 2.5-month-old girl admitted for failure to thrive and severe pancytopenia was diagnosed with methylmalonic acidemia (MMA) secondary to transcobalamin II deficiency, an inborn error of vitamin B12 metabolism. Opportunistic Cytomegalovirus and Pneumocystis jirovecii pneumonia led to severe acute respiratory distress syndrome (ARDS) and immune reconstitution inflammatory syndrome (IRIS) after treatment initiation with vitamin B12 supplementation. In children with interstitial pneumonia-related ARDS, normal lymphocyte count should not delay invasive procedures required to document opportunistic infections. MMA can be associated with underlying lymphocyte dysfunction and vitamin B12 supplementation can fully reverse the associated immunodeficiency. IRIS may appear in highly treatment-responsive forms of pancytopenia in children and prompt treatment of dysregulated inflammation with high-dose corticosteroids should be initiated

Immune system · Methylmalonic acidemia · Pancytopenia · Presentation (obstetrics · Blood disorders and treatments · Hematological disorders and diagnostics · Medicine · Pneumocystis jirovecii pneumonia detection and treatment · Immunology · Pediatrics · Surgery