Primary immunodeficiencies in Tygerberg Hospital and on the national PID Registry, South Africa

Van Velden, Mia (2019-12)

Thesis (MMed)--Stellenbosch University, 2021.

Thesis

Introduction: Little is known about the prevalence of primary immunodeficiencies (PID) in South Africa. The purpose of this study was to describe the profile and spectrum of patients affected by PID referred to the Tygerberg Hospital Immunology Service, situated in the Western Cape province of South Africa, during the past 25 years. Methods: This study entailed a retrospective descriptive analysis of the epidemiological data of patients with suspected PID referred to Tygerberg Hospital Immunology Service between 1 January 1991 and 5 May 2016. Data collected included date of birth, diagnosis, age at diagnosis, geographic origin, ethnicity, referral site, family history of PIDs, presenting features, immunological tests done, and outcome (alive or dead). The diagnosis was classified according to the International Union of Immunological Societies (IUIS) published in April 2014 and the European Society for Immunodeficiency published in July 2016 or listed as ‘other’. Results: The patient cohort included 500 patients between 0 and 60 years with a median age of 5 years (interquartile range=10). The majority of patients (70%) were from the Western Cape and were referred by paediatricians not linked to tertiary institutions (43%). The most common clinical presentation was recurrent respiratory tract infections (60%). The male to female ratio was 1.2:1. The main categories of PID, according to the IUIS criteria, were antibody deficiencies (52,80%), followed by complement deficiencies (19,80%), combined immunodeficiencies (7,12%), combined immunodeficiencies with associated syndromic features (6,25%), autoinflammatory disorders (3,40%), congenital defects of phagocyte number and/or function (4,20%), and defects in innate immunity (1,26%). There were no patients with phenocopies of PID disorders. The majority of patients were Caucasian (59,40%), who had antibody deficiencies (39,00%) as most common diagnosis. This was followed by 24,80% mixed- race patients and 11,60% black African patients, who mostly had complement deficiencies (10,00% and 4,00%, respectively). Conclusion: The median age of diagnosis of PID in this study was older than those in studies in other developing countries, but clinical presentation and types of PID were similar to reports from other developing countries with low rates of consanguinity. However, there was an increased number of patients diagnosed with complement deficiencies (specifically hereditary angioedema) in the Western Cape.

Inleiding: Daar is weinig studies aangaande die voorkoms van primêre immuungebreke (PIG) in Suid- Afrika. Die doel van dié studie was om die profiel en spektrum te bepaal van pasiënte met PIG wat oor die afgelope 25 jaar verwys is na die Tygerberg-immunologiekliniek in die Wes-Kaap. Metodes: Die studie is ’n retrospektiewe beskrywende analise van die epidemiologiese data van pasiënte, vermoedelik met PIG, wat tussen 1 Januarie 1991 en 5 Mei 2016 na Tygerberg Hospitaal verwys is. Die ingesamelde data het die geboortedatum, diagnose, ouderdom ten tye van diagnose, geografiese oorsprong, etnisiteit, verwysingsbron, familiegeskiedenis van PIG, presenterende simptome, of daar immunologiese toetse gedoen is, en die uitkoms (of die pasiënt lewend is/ gesterf het) ingesluit. Die diagnose is geklassifiseer volgens die riglyne van die Internasionale Unie van Immunologiese Gemeenskappe (IUIG), wat in April 2014 gepubliseer is, sowel as dié van die Europese Gemeenskap vir Immuungebrekkigheid, in Julie 2016 gepubliseer, of as ‘ander’ uitgelig. Resultate: Die pasiëntkohort het 500 pasiënte tussen 0 en 60 jaar met ʼn mediane ouderdom van 5 jaar (interkwartiel variasie =10) ingesluit. Die meerderheid (70%) van die pasiënte was van die Wes-Kaap en is deur pediaters verwys wat nie verwant is aan tersiêre hospitale in die Wes-Kaap nie (43%). Die algemeenste presenterende klagte was herhalende respiratoriese infeksies (60%). Die verhouding van mans tot vrouens was 1.2:1. Volgens die IUIG klassifikasie was die hoofkategorieë van PIG antiliggaamdefekte (52,80%), gevolg deur komplementdefekte (19,80%), gekombineerde immuungebrekkigheid (7,12%), gekombineerde immuungebrekkigheid met geassosieerde sindromiese kenmerke (6,25%), outo-inflammatoriese defekte (3,40%), kongenitale defekte van fagosietgetal en/ of -funksie (4,20%), en defekte in aangebore immuniteit (1,26%). Daar was geen pasiënte met fenokopieë van PIG nie. Die meerderheid van pasiënte was van Kaukasiese herkoms (59,40%) met antiliggaam defekte (39,00%) as hoofdiagnose. Dit is gevolg deur 24,80% pasiënte van gemengde herkoms en 11,60% swart pasiënte – albei groepe het komplementdefekte (10% en 4% onderskeidelik) as hoofdiagnose gehad. Gevolgtrekking: Die mediane ouderdom ten tye van diagnose met PIG in hierdie studie was ouer in vergelyking met studies in ander ontwikkelende lande. maar kliniese presentering en PIG-tipes was soortgelyk aan die van ander ontwikkelende lande met ’n lae voorkoms van bloedverwantskap. Daar is egter ’n groter aantal pasiënte met komplimentdefekte (spesifiek oorgeërfde angio-edeem) in die Wes- Kaap gediagnoseer.

Please refer to this item in SUNScholar by using the following persistent URL: http://hdl.handle.net/10019.1/106976
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