Prolidase deficiency, a rare inborn error of immunity, clinical phenotypes, immunological features, and proposed treatments in twins

Bibliographic Details
Title: Prolidase deficiency, a rare inborn error of immunity, clinical phenotypes, immunological features, and proposed treatments in twins
Authors: Nora Alrumayyan, Drew Slauenwhite, Sarah M. McAlpine, Sarah Roberts, Thomas B. Issekutz, Adam M. Huber, Zaiping Liu, Beata Derfalvi
Source: Allergy, Asthma & Clinical Immunology, Vol 18, Iss 1, Pp 1-11 (2022)
Publisher Information: BMC, 2022.
Publication Year: 2022
Collection: LCC:Immunologic diseases. Allergy
Subject Terms: Prolidase deficiency, T cells, Inborn error of immunity, Autoimmunity, Leg ulcers, Immunologic diseases. Allergy, RC581-607
More Details: Abstract Background Prolidase deficiency (PD) is an autosomal recessive inborn multisystemic disease caused by mutations in the PEPD gene encoding the enzyme prolidase D, leading to defects in turnover of proline-containing proteins, such as collagen. PD is categorized as a metabolic disease, but also as an inborn error of immunity. PD presents with a range of findings including dysmorphic features, intellectual disabilities, recurrent infections, intractable skin ulceration, autoimmunity, and splenomegaly. Despite symptoms of immune dysregulation, only very limited immunologic assessments have been reported and standard therapies for PD have not been described. We report twin females with PD, including comprehensive immunologic profiles and treatment modalities used. Case presentation Patient 1 had recurrent infections in childhood. At age 13, she presented with telangiectasia, followed by painful, refractory skin ulcerations on her lower limbs, where skin biopsy excluded vasculitis. She had typical dysmorphic features of PD. Next-generation sequencing revealed pathogenic compound heterozygous mutations (premature stop codons) in the PEPD gene. Patient 2 had the same mutations, typical PD facial features, atopy, and telangiectasias, but no skin ulceration. Both patients had imidodipeptiduria. Lymphocyte subset analysis revealed low-normal frequency of Treg cells and decreased frequency of expression of the checkpoint molecule CTLA-4 in CD4+ TEM cells. Analysis of Th1, Th2, and Th17 profiles revealed increased inflammatory IL-17+ CD8+ TEM cells in both patients and overexpression of the activation marker HLA-DR on CD4+ TEM cells, reflecting a highly activated proinflammatory state. Neither PD patient had specific antibody deficiencies despite low CD4+CXCR5+ Tfh cells and low class-switched memory B cells. Plasma IL-18 levels were exceptionally high. Conclusions Immunologic abnormalities including skewed frequencies of activated inflammatory CD4+ and CD8+ TEM cells, decreased CTLA-4 expression, and defects in memory B cells may be a feature of immune dysregulation associated with PD; however, a larger sample size is required to validate these findings. The high IL-18 plasma levels suggest underlying autoinflammatory processes.
Document Type: article
File Description: electronic resource
Language: English
ISSN: 1710-1492
Relation: https://doaj.org/toc/1710-1492
DOI: 10.1186/s13223-022-00658-2
Access URL: https://doaj.org/article/03ad05a01adb459c9c83d1949a6d70a8
Accession Number: edsdoj.03ad05a01adb459c9c83d1949a6d70a8
Database: Directory of Open Access Journals
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More Details
ISSN:17101492
DOI:10.1186/s13223-022-00658-2
Published in:Allergy, Asthma & Clinical Immunology
Language:English