Zainab Alawi, Saudi Arabia
King Faisal Specialist Hospital & Research center Pediatric Allergy & ImmunologyPresenter of 1 Presentation
A PATIENT WITH PURINE NUCLEOSIDE PHOSPHORYLASE DEFICIENCY PRESENTED LATE WITH SYSTEMIC LUPUS ERYTHEMATOSUS AND COMPLICATED BY EBV-INDUCED CNS LYMPHOMA
Abstract
Background and Aims
Purine nucleoside phosphorylase (PNP) deficiency accounts for about 2% of severe combined immunodeficiency diseases. PNP deficiency is a variable disease with recurrent infections and neurodevelopmental delay; autoimmunity and malignancy which still occur in one third of the patients.
Methods
Case report and genetic diagnosis.
Results
We reported a 9-year-old Saudi female who was apparently healthy, presented at the age of 8 years with confirmed SLE that was poorly controlled with conventional therapy. During that time, she attained frequent sinopulmonary and varicella infections. Preliminary immunological workup showed severe lymphopenia and depressed lymphocyte proliferation assay. Genetic study revealed a homozygous missense mutation c.265 G>A in the NP gene, resulting in a substitution of glutamic acid to lysine at amino acid 89 of the NP protein (E89K). Hematopoietic stem cell transplantation was planned from a matched unrelated donor, however she developed focal seizures with secondary generalization. An EBV and Varicella meningoencephalitis was confirmed and failed to be cleared with appropriate antiviral therapy. Atypical malignant cells suggestive of lymphoma was discovered and was believed to be EBV induced. Suspicious lesions were exhibited on brain MRI and PET scan. Unfortunately, brain biopsy was not performed owing to the severe illness of the patient who subsequently passed away before HSCT at the age of 9 years due to multi-organ failure.
Conclusions
Our report expands the spectrum of clinical presentation of PNP deficiency as SLE being the solely presenting feature. Subtle psychomotor developmental delay and increased predisposition to viral infections in SLE patients may warrant investigating the PNP enzyme activity.