Related Experiment Video
Updated: Sep 26, 2026

Establishment of Epstein-Barr Virus Growth-transformed Lymphoblastoid Cell Lines
Published on: November 8, 2011
[Persistent polyclonal B-cell lymphocytosis]
U Schönermarck1, H Diem, P Lohse
1Schwerpunkt Nephrologie, Medizinische Klinik und Poliklinik I, Klinikum der udwig-Maximilians-Universität München, Munich.
History And Clinical Findings:
A 54-year-old woman was referred for ambulant checkup after an episode of acute renal failure due to severe gastroenteritis and recurrent arthralgias. Physical examination was unremarkable except for the presence of palpable small cervical lymph nodes.
Investigations:
Serum IgM levels showed a polyclonal increase. All the other routinely examined parameters were within normal limits. Microscopical blood smear examination revealed binucleated lymphocytes. Immunophenotyping of peripheral blood showed a polyclonal B-cell lymphocytosis despite normal numbers of leukocytes and lymphocytes. PCR analysis identified cells with a t(14;18) translocation (bcl-2/IgH rearrangement).
Diagnosis:
A routine medical checkup disclosed the diagnosis of persistent polyclonal B-cell lymphocytosis. This rare benign lymphoproliferative disorder is characterized by binucleated lymphocytes, polyclonal expansion of B-cells, and a polyclonal increase in serum IgM. The diagnosis was established despite the lack of leukocytosis or lymphocytosis in the peripheral blood.
Conclusions:
Because of its benign and indolent course without the need for chemotherapy, it is important to discriminate the disorder of persistent polyclonal B-cell lymphocytosis from other malignant lymphoproliferative diseases.
Related Concept Videos
Cells of the Adaptive Immune Response
B Cell Activation and Differentiation
When naive B cells encounter a specific antigen that can bind to the B cell receptor (BCR) on their surface, they undergo sensitization to respond to the antigen's presence. Sensitization begins with...
Disorders of Leukocytes
Leukopenia may result from bone marrow disorders, autoimmune diseases, and infectious diseases. For example, conditions such as multiple myeloma and aplastic anemia can impair the bone marrow's ability to produce adequate leukocytes. Similarly, autoimmune diseases like lupus and viral infections such as HIV can prompt the immune system...
Primary Lymphoid Organs
The red bone marrow is a soft, spongy tissue nestled in the interior of long bones such as the humerus and femur. It is the site...
T Cell Activation and Clonal Selection
Naive T cells that have not yet encountered an antigen express two primary CD...
Lymphoid Cells and Tissues
Lymphoid cells consist of various types of immune system cells. These include B and T lymphocytes, which are responsible for producing antibodies and killing infected cells, respectively. Dendritic cells act as messengers between the innate and adaptive...
