{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,8,20]],"date-time":"2026-08-20T15:53:15Z","timestamp":1787241195106,"version":"build-2736575974"},"reference-count":34,"publisher":"MDPI AG","issue":"15","license":[{"start":{"date-parts":[[2024,7,24]],"date-time":"2024-07-24T00:00:00Z","timestamp":1721779200000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"name":"Project \u201cItalian Network for Advanced Diagnosis and Treatment of IEIs\u201d","award":["PNRRMR1-2022-12376594"],"award-info":[{"award-number":["PNRRMR1-2022-12376594"]}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["JCM"],"abstract":"<jats:p>Background: An unclassified primary antibody deficiency (unPAD) is a widely heterogeneous clinical entity, recently identified within the spectrum of Inborn Errors of Immunity (IEIs). Since unPAD has been traditionally considered as a mild condition, it has incorrectly received little attention, resulting in the paucity of extensive and comparable studies describing its natural history. To address the gaps in characterizing, understanding, and managing pediatric unPAD patients, the Italian Primary Immunodeficiency Network (IPINet) Ped-unPAD study has recently been launched. Methods: Seventeen IPINeT Centers have expressed interest to participate, and data collection is still on-going. Hereby, we anticipate preliminary key issues emerging from the first 110 enrolled patients, attending three IPINet Centers. Results: A proportion of unPAD patients have experienced a severe infectious phenotype, which required hospitalization in a quarter of patients and antibiotic prophylaxis or Immunoglobulin Replacement Therapy in approximately 10% of patients. In this partial cohort, a mean follow-up (FU) of 5 years confirmed unPAD diagnosis in fifty percent of cases, with the remaining being reclassified as the Transient Hypogammaglobulinemia of Infancy (25%) and other IEIs (25%), such as a Common Variable Immunodeficiency, Selective IgA deficiency, Selective IgM deficiency, and IgG3 subclass deficiency. Conclusions: Despite a phenotype overlap at diagnosis, clinicians should be aware that unPAD is a mutable condition that deserves comprehensive evaluation and long-term monitoring to dissect the final diagnosis for optimal treatment.<\/jats:p>","DOI":"10.3390\/jcm13154321","type":"journal-article","created":{"date-parts":[[2024,7,24]],"date-time":"2024-07-24T14:55:47Z","timestamp":1721832947000},"page":"4321","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":2,"title":["IPINeT Ped-unPAD Study: Goals, Design, and Preliminary Results"],"prefix":"10.3390","volume":"13","author":[{"ORCID":"https:\/\/orcid.org\/0000-0002-7493-5226","authenticated-orcid":false,"given":"Mayla","family":"Sgrulletti","sequence":"first","affiliation":[{"name":"Pediatric Immunopathology and Allergology Unit, Policlinico Tor Vergata, University of Rome Tor Vergata, 00133 Rome, Italy"},{"name":"PhD Program in Immunology, Molecular Medicine and Applied Biotechnology, University of Rome Tor Vergata, 00133 Rome, Italy"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Lucia Augusta","family":"Baselli","sequence":"additional","affiliation":[{"name":"Pediatric Immunorheumatology Unit, Fondazione IRCCS Ca\u2019 Granda Ospedale Maggiore Policlinico, 20122 Milan, Italy"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-0029-9383","authenticated-orcid":false,"given":"Riccardo","family":"Castagnoli","sequence":"additional","affiliation":[{"name":"Pediatric Unit, Department of Clinical, Surgical, Diagnostic, and Pediatric Sciences, University of Pavia, 27100 Pavia, Italy"},{"name":"Pediatric Clinic, Fondazione IRCCS Policlinico San Matteo, 27100 Pavia, Italy"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Elisabetta","family":"Del Duca","sequence":"additional","affiliation":[{"name":"Pediatric Immunopathology and Allergology Unit, Policlinico Tor Vergata, University of Rome Tor Vergata, 00133 Rome, Italy"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Simona","family":"Graziani","sequence":"additional","affiliation":[{"name":"Pediatric Immunopathology and Allergology Unit, Policlinico Tor Vergata, University of Rome Tor Vergata, 00133 Rome, Italy"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Giusella Maria Francesca","family":"Moscato","sequence":"additional","affiliation":[{"name":"Pediatric Immunopathology and Allergology Unit, Policlinico Tor Vergata, University of Rome Tor Vergata, 00133 Rome, Italy"},{"name":"Department of System Medicine, University of Rome Tor Vergata, 00133 Rome, Italy"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-9912-7997","authenticated-orcid":false,"given":"Silvia","family":"Di Cesare","sequence":"additional","affiliation":[{"name":"Unit of Clinical Immunology and Vaccinology, IRCCS Bambino Ges\u00f9 Children\u2019s Hospital, 00165 Rome, Italy"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Gigliola","family":"Di Matteo","sequence":"additional","affiliation":[{"name":"Department of System Medicine, University of Rome Tor Vergata, 00133 Rome, Italy"},{"name":"Primary Immunodeficiency Research Unit, IRCCS Bambino Ges\u00f9 Children\u2019s Hospital, 00165 Rome, Italy"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Cristina","family":"Cifaldi","sequence":"additional","affiliation":[{"name":"Department of System Medicine, University of Rome Tor Vergata, 00133 Rome, Italy"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Martina","family":"Rossano","sequence":"additional","affiliation":[{"name":"Pediatric Immunorheumatology Unit, Fondazione IRCCS Ca\u2019 Granda Ospedale Maggiore Policlinico, 20122 Milan, Italy"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-4849-0390","authenticated-orcid":false,"given":"Claudia","family":"Ballerini","sequence":"additional","affiliation":[{"name":"Universit\u00e0 degli Studi di Milano, 20122 Milan, Italy"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-8648-885X","authenticated-orcid":false,"given":"Alfonso","family":"Piciocchi","sequence":"additional","affiliation":[{"name":"GIMEMA Data Center, Fondazione GIMEMA Franco Mandelli Onlus, 00182 Rome, Italy"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-1773-6482","authenticated-orcid":false,"given":"Amelia","family":"Licari","sequence":"additional","affiliation":[{"name":"Pediatric Unit, Department of Clinical, Surgical, Diagnostic, and Pediatric Sciences, University of Pavia, 27100 Pavia, Italy"},{"name":"Pediatric Clinic, Fondazione IRCCS Policlinico San Matteo, 27100 Pavia, Italy"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Gian Luigi","family":"Marseglia","sequence":"additional","affiliation":[{"name":"Pediatric Unit, Department of Clinical, Surgical, Diagnostic, and Pediatric Sciences, University of Pavia, 27100 Pavia, Italy"},{"name":"Pediatric Clinic, Fondazione IRCCS Policlinico San Matteo, 27100 Pavia, Italy"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-5968-1945","authenticated-orcid":false,"given":"Rita","family":"Consolini","sequence":"additional","affiliation":[{"name":"Section of Clinical and Laboratory Immunology, Pediatrics Unit, Department of Clinical and Experimental Medicine, University of Pisa, 56126 Pisa, Italy"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Viviana","family":"Moschese","sequence":"additional","affiliation":[{"name":"Pediatric Immunopathology and Allergology Unit, Policlinico Tor Vergata, University of Rome Tor Vergata, 00133 Rome, Italy"},{"name":"Department of System Medicine, University of Rome Tor Vergata, 00133 Rome, Italy"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1968","published-online":{"date-parts":[[2024,7,24]]},"reference":[{"key":"ref_1","unstructured":"(2024, May 01). 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