Medicine & USMLE

Plasma B Cells

B Cells and T Cells
  1. MHC I
  2. MHC II
  3. B Cells - Overview
  4. B Cells - Activation
  5. Plasma B Cells
  6. Memory B Cells
  7. T Cells - Overview
  8. T Cells - Activation
  9. T Cells - Differentation
  10. Cytotoxic (Killer) T Cells
  11. Helper T Cells - Overview
  12. Th1 Cells
  13. Th2 Cells
  14. Th17 Cells
  15. Regulatory T Cells (Tregs)


Plasma B cells are a subset of activated B-lymphocytes. They produce soluble antibodies against specific antigens. On microscopy, plasma B-cells are distinguished by their clock-faced chromatin distribution and eccentric nuclei. Plasma cells are typically found in the bone marrow.

Key Points

  • Plasma B Cells
    • Effector B-cell produced after B-cell Activation
    • Provide humoral immunity by producing antibodies against an antigen
    • “Clock face” nuclear chromatin and eccentric (off-center) nucleus
      • Eccentric nucleus due to large RER/Golgi secondary to robust antibody production
    • Found in bone marrow
      • Activated B-lymphocytes migrate from lymphoid tissue back to marrow
      • Normally do not circulate in peripheral blood