@article{Gertjan J. Driessen_Virgil A.S.H. Dalm_P. Martin van Hagen_H. Anne Grashoff_Nico G. Hartwig_Annemarie M. C. van Rossum_Adilia Warris_Esther de Vries_Barbara H. Barendregt_Ingrid Pico_Sandra Posthumus_Menno C. van Zelm_Jacques J.M. van Dongen_Mirjam van der Burg_2013, place={Pavia, Italy}, title={Common variable immunodeficiency and idiopathic primary hypogammaglobulinemia: two different conditions within the same disease spectrum}, volume={98}, url={https://haematologica.org/article/view/6814}, DOI={10.3324/haematol.2013.085076}, abstractNote={Patients with hypogammaglobulinemia who do not fulfill all the classical diagnostic criteria for common variable immunodeficiency (reduction of two immunoglobulin isotypes and a reduced response to vaccination) constitute a diagnostic and therapeutic dilemma, because information concerning the clinical and immunological characteristics of these patients with idiopathic primary hypogammaglobulinemia is not available. In 44 common variable immunodeficiency and 21 idiopathic primary hypogammaglobulinemia patients we determined the clinical phenotypes and performed flow cytometric immunophenotyping to assess the pathophysiological B-cell patterns and memory B-cell subset counts. Age-matched B-cell subset reference values of 130 healthy donors were generated. Severe pneumonia and bronchiectasis occurred at similar frequencies in idiopathic primary hypogammaglobulinemia and common variable immunodeficiency. Although IgG levels were only moderately reduced compared to common variable immunodeficiency, 12 of 21 idiopathic primary hypogammaglobulinemia patients required immunoglobulin replacement. Non-infectious disease-related clinical phenotypes (autoimmune cytopenia, polyclonal lymphocytic proliferation and persistent unexplained enteropathy) were exclusively observed in common variable immunodeficiency and were associated with early peripheral B-cell maturation defects or B-cell survival defects. T-cell dependent memory B-cell formation was more severely affected in common variable immunodeficiency. Furthermore, 14 of 21 idiopathic primary hypogammaglobulinemia patients showed normal peripheral B-cell subset counts, suggestive for a plasma cell defect. In conclusion, idiopathic primary hypogammaglobulinemia patients who do not fulfill all diagnostic criteria of common variable immunodeficiency have moderately decreased immunoglobulin levels and often a normal peripheral B-cell subset distribution, but still suffer from serious infectious complications.}, number={10}, journal={Haematologica}, author={Gertjan J. Driessen and Virgil A.S.H. Dalm and P. Martin van Hagen and H. Anne Grashoff and Nico G. Hartwig and Annemarie M. C. van Rossum and Adilia Warris and Esther de Vries and Barbara H. Barendregt and Ingrid Pico and Sandra Posthumus and Menno C. van Zelm and Jacques J.M. van Dongen and Mirjam van der Burg}, year={2013}, month={Oct.}, pages={1617-1623} }