In order to be enrolled, participants must be 18 years or older, able to understand study procedures, provide written informed consent (Biobank informed consent and study specific informed consent), and meet one of the following inclusion criteria: 1. Noninfectious immunocompetent participants (i.e., healthy participants) as determined by medical history and clinical judgement. or 2. Patients with primary immunodeficiencies or 3. Patients with B-cell depleting therapy due autoimmune disease or 4. Patients with benign and malignant hematological diseases receiving specific treatments with known immunosuppressive effects including cytotoxic agents, systemic corticosteroids, monoclonal antibodies and targeted therapies. or 5. Patients with active hematological diseases and secondary immunoglobulin deficiency (e.g. CLL, MM) currently not receiving specific treatment. or 6. Patients >3 months but <12 months after autologous HSCT. or 7. Patients >3 months but <12 months after allogeneic HSCT. or 8. Recipients of HSCT >12 months after allogeneic HSCT but under immunosuppressive therapy. or 9. Patients with chronic GvHD and persistent immunodeficiency.

In order to be enrolled, participants must be 18 years or older, able to understand study procedures, provide written informed consent (Biobank informed consent and study specific informed consent), and meet one of the following inclusion criteria: 1. Noninfectious immunocompetent participants (i.e., healthy participants) as determined by medical history and clinical judgement. or 2. Patients with primary immunodeficiencies or 3. Patients with B-cell depleting therapy due autoimmune disease or 4. Patients with benign and malignant hematological diseases receiving specific treatments with known immunosuppressive effects including cytotoxic agents, systemic corticosteroids, monoclonal antibodies and targeted therapies. or 5. Patients with active hematological diseases and secondary immunoglobulin deficiency (e.g. CLL, MM) currently not receiving specific treatment. or 6. Patients >3 months but <12 months after autologous HSCT. or 7. Patients >3 months but <12 months after allogeneic HSCT. or 8. Recipients of HSCT >12 months after allogeneic HSCT but under immunosuppressive therapy. or 9. Patients with chronic GvHD and persistent immunodeficiency.