INTRODUCTION:
Secondary immunodeficiencies (SID) are acquired declines of immune cell counts and or/ function. The distinction between Inborn errors of immunity(IEIs) and SID sometimes is a challenge for the immunologist, the latter being more frequently diagnosed than IEIs and can occur as a consequence of malnutrition, metabolic disorders, use of immunosuppressive medications, chronic infections, malignancies and severe trauma among others.
We describe pediatric and adult patients with secondary immunodeficiencies in a single center of Argentina. METHOD: 33 patients (pts) with SID were included in a retrospective analysis of clinical records from our outpatient clinic from 01.2008 until 01.2023. 2pts in the follow up were recategorized with Common variable immunodeficiency and excluded. RESULTS: 21 females and 10 males. The median age was 39yo (range 4-87 yo). The causes of SID were: 11/31pts (35.48%) oncohematological diseases (CLL, Hodgkin’s disease, non-Hodgkin lymphoma), 4/31pts (12.90%) antiepileptic treatment (valproate, lamotrigine and clobazam), 4/31pts (12.90%) protein loss, 2/31pts (6.45% ) rheumatological diseases, 2/31pts (6.45%) immune system immaturity, 1/31pt (3.22%) pos-rituximab,1/31pt (3.22%) with hystiocitosis, and 7/31pts (22.58 %) no cause were identified and IEI was rule out. Diagnosed was based on: hypogammaglobulinemia 24/31pts (77.41%). IgG mean serum level: 510 mg/dl (range 108 mg/dl-1305 mg/dl). Poor Response to vaccines 7/31pts(22,58%), Lymphocytes subsets with B-cell lymphopenia 10/31pts(32.25%). Treatment: 9/31pts (29.03%) were under Immunoglobulin replacement therapy due to severe infections. 8/31pts(25,80%) had prophylactic antibiotics due to mild infections.
CONCLUSION:
Is known that patients with IEIs have an increase of malignancies and autoimmune disorders, highly variable presentation mean that antibody deficiencies initially attributed to SID due to underlying disease and/or therapeutic agents used to treat hematological malignancies and autoimmune disorders, may actually be due to an underlying IEI.
Key words: secondary immunodeficiencies, inborn error of immunity, b cells, Immunoglobulin replacement therapy.