AUTHOR=Abolhassani Hassan , Avcin Tadej , Bahceciler Nerin , Balashov Dmitry , Bata Zsuzsanna , Bataneant Mihaela , Belevtsev Mikhail , Bernatowska Ewa , Bidló Judit , Blazsó Péter , Boisson Bertrand , Bolkov Mikhail , Bondarenko Anastasia , Boyarchuk Oksana , Bundschu Anna , Casanova Jean-Laurent , Chernishova Liudmyla , Ciznar Peter , Csürke Ildikó , Erdős Melinda , Farkas Henriette , Fomina Daria S. , Galal Nermeen , Goda Vera , Guner Sukru Nail , Hauser Péter , Ilyina Natalya I. , Iremadze Teona , Iritsyan Sevan , Ismaili-Jaha Vlora , Jesenak Milos , Kelecic Jadranka , Keles Sevgi , Kindle Gerhard , Kondratenko Irina V. , Kostyuchenko Larysa , Kovzel Elena , Kriván Gergely , Kuli-Lito Georgina , Kumánovics Gábor , Kurjane Natalja , Latysheva Elena A. , Latysheva Tatiana V. , Lázár István , Markelj Gasper , Markovic Maja , Maródi László , Mammadova Vafa , Medvecz Márta , Miltner Noémi , Mironska Kristina , Modell Fred , Modell Vicki , Mosdósi Bernadett , Mukhina Anna A. , Murdjeva Marianna , Műzes Györgyi , Nabieva Umida , Nasrullayeva Gulnara , Naumova Elissaveta , Nagy Kálmán , Onozó Beáta , Orozbekova Bubusaira , Pac Malgorzata , Pagava Karaman , Pampura Alexander N. , Pasic Srdjan , Petrosyan Mery , Petrovic Gordana , Pocek Lidija , Prodeus Andrei P. , Reisli Ismail , Ress Krista , Rezaei Nima , Rodina Yulia A. , Rumyantsev Alexander G. , Sciuca Svetlana , Sediva Anna , Serban Margit , Sharapova Svetlana , Shcherbina Anna , Sitkauskiene Brigita , Snimshchikova Irina , Spahiu-Konjusha Shqipe , Szolnoky Miklós , Szűcs Gabriella , Toplak Natasa , Tóth Beáta , Tsyvkina Galina , Tuzankina Irina , Vlasova Elena , Volokha Alla TITLE=Care of patients with inborn errors of immunity in thirty J Project countries between 2004 and 2021 JOURNAL=Frontiers in Immunology VOLUME=Volume 13 - 2022 YEAR=2022 URL=https://www.frontiersin.org/journals/immunology/articles/10.3389/fimmu.2022.1032358 DOI=10.3389/fimmu.2022.1032358 ISSN=1664-3224 ABSTRACT=In this study, meeting profiles and major diagnostic and treatment parameters of the J Project (JP) were studied. JP center leaders reported patients’ data from 30 countries representing a total population of 506 567 565. The number of JP meetings increased from 6 per year in 2004 and 2005 to 44 and 63 in 2020 and 2021, respectively. The cumulative number of meetings per country varied from 1 to 59 in various countries reflecting partly but not entirely the population of the respective countries. Altogether, 24,862 patients were reported giving an average prevalence of 4.9. Most of the patients had predominantly antibody deficiency (46.29 %) followed by patients with combined immunodeficiencies (14.3%). The percentages of patients with bone marrow failure and phenocopies of IEI were less than 1 each. The number of patients was remarkably higher that those reported to the ESID Registry in 13 countries. Immunoglobulin (IgG) substitution was provided to 7,572 patients (5,693 intravenously) and 1,468 patients received hematopoietic stem cell therapy (HSCT). Searching for basic diagnostic parameters revealed the availability of both immunochemistry and flow cytometry in 26 countries, and targeted gene sequencing and new generation sequencing was available in 16 countries. The number of IEI centers and experts in the field were 260 and 690, respectively. We found high correlation between the number of IEI centers and patients treated with intravenous IgG (IVIG) (correlation coefficient, cc, 0.994) and with those who were treated with HSCT (cc, 0.868). Similar correlation was found when the number of experts was compared with these two parameters. However, the number of patients treated with subcutaneous Ig only slightly correlated with the number of experts (cc, 0.526) and no correlation was found between the number of centers and patients on SCIG (cc, 0.105).