X-linked severe combined immunodeficiency (X-SCID) with high blood levels of immunoglobulins and Aspergillus pneumonia successfully treated with micafangin followed by unrelated cord blood stem cell transplantation

In this report, we describe a patient with X-linked severe combined immunodeficiency (X-SCID) who had high serum IgG, IgA, and IgM levels. The boy did well until 6 months of age, when he developed interstitial pneumonia caused by Aspergillus species, with a white cell count of 12,840/μL and only 10% lymphocytes; IgG, 991 mg/dL; IgA, 65 mg/dL; IgM, 472 mg/dL. Cell markers showed only 6.3% CD3, 2.1% CD4, 0.7% CD8, but 92% CD19 and 0.1% CD16+CD56+ (NK cells). A mutation was detected within exon 2 (C196 A→C), leading to the substitution of proline for glutamine, which has not been reported previously. The boy was successfully treated with the new antifungal drug, micafangin (MCFG), at 5 mg/kg/day for 89 days. After resolution of the pneumonia, the patient underwent successful hematopoietic stem cell transplantation with completely matched unrelated female cord blood. The CD34 stem cell dose was 3.4×10⁴ cells/kg. In conclusion, MCFG can be a first line agent for Aspergillus pneumonia in immunocompromised hosts.