Late onset combined immune deficiency (LOCID) is recently described in patients with previous infection indicative of a severe defect in cell-mediated immunity and/or low CD4+ cell counts. This disease can occur at any age and it is extremely heterogeneous. Authors present here two new observations.
We describe the diagnosis of LOCID in two patients followed in the pediatric immune-hematology unit.
Case1: A 59-year-old woman with a history of B lymphoma diagnosed after two episodes of deep vein thrombosis and lower respiratory tract infections leading to bronchiectasis and postinfectious obliterating bronchopathy. The diagnosis of LOCID was retained in front of hypogammaglobulinemia (IgG=0.17g/L, IgA=0.02g/L , IgM=0.1g/L), B-lymphocytes at 1% and criteria of profound T cell deficiency (Lymphocytes=1000/mm3, CD4+ at 15.5% and CD4 naive at 4%).
Case2: A 22-year-old girl, from non-consanguineous parents, with family history of early death. In her past medical history, the patient had celiac disease with Evans syndrome at 12 years old. LOCID was suspected in front of the association of infectious episodes: oral candidiasis, recurrent upper and lower respiratory tract infections with bronchiectasis, hemi-corporal zona with severe retinal zoster and splenomegaly. Immunity exploration found hypogammaglobulinemia (IgG=3.4g/L, IgA=0.15g/L, IgM=0.2g/L) and 1%B lymphocyte count, decreased switched memory B cells , CD4+ at 25% (440/mm3).
Both patients responded to polyvalent immunoglobulin and anti-infectious prophylaxis (1 and 6 years follow-up, respectively) without evidence of immune reconstitution.
LOCID is still underdiagnosed. The main differential diagnosis is common variable immunodeficiency(CIVD). Systematic T cell phenotype may help to discriminate such patients from those with CVID.