Interstitial pneumonia as the initial presentation in an infant with a novel mutation of CD40 ligand-associated X-linked hyper-IgM syndrome: A case report.Medicine (Baltimore). 2020 Jun 12; 99(24):e20505.M
X-linked hyper-IgM syndrome is a type of primary combined immunodeficiency disorder caused by mutations in CD40 ligand. Opportunistic infections caused by P jirovecii, cytomegalovirus (CMV), or fungi are frequently the first presenting symptom of the patients with X-linked hyper-IgM syndrome.
Here, we report a 10-month-old infant who presented with cyanosis and shortness of breath. The infant exhibited no medical or birth history indicating a primary immune deficiency and was first diagnosed with interstitial pneumonia and acute respiratory failure on admission.
The infant was diagnosed with Pneumocystis jirovecii pneumonia combined with CMV and fungal infection through gene sequencing by nasopharyngeal swab and G-test. Whole-exome sequencing from a blood sample was performed and identified a functional mutation across the CD40 ligand gene (NM_000074;exon1;C.86_87del) resulting in an amino acid change (P.T29Sfl*18) attributed to X-linked hyper IgM syndrome.
The infant received continuous positive airway pressure ventilation treatment combined with trimethoprim-sulfamethoxazole for Pneumocystis jirovecii pneumonia, ganciclovir for CMV, voriconazole for fungal infection and substitution of high-dose immunoglobulin.
Six months after discharge from our hospital, the infant remained well.
Opportunistic infections should be suspected in infants presenting with severe interstitial pneumonia. Primary immune deficiency diseases should also be considered in infants diagnosed with opportunistic infections.