Persistent polyclonal B-cell lymphocytosis

Persistent polyclonal B-cell lymphocytosis (PPBL) is an anomaly of the human immune system characterized by mildly elevated levels of white blood cells (called leukocytosis), chronic, stable absolute polyclonal B-cell lymphocytosis, elevated polyclonal IgM and binucleated cells. Although cases of non-smoking women or men have been reported, patients are predominantly young smoking women.

Signs and symptoms

Ten percent of patients present with splenomegaly and lymphadenopathy. Some patients report a varying degree of fatigue, consistent with a chronic fatigue syndrome,^[1] or postviral fatigue as seen in EBV infections while others remain asymptomatic.^[2]

Genetics

Genetically, PPBL has been associated with a few unusual genetic characteristics. Among them, it is associated with a particular genetic variant of the human leukocyte antigen called HLA-DR7. This variant is normally present in 26% in the Caucasian population. Chromosome analysis has detected an isochromosome +i(3q), with or without premature chromosome condensation. Also, a t(14;18)(q22;21) bcl-2/IgH rearrangement has been described, as usually seen in follicular lymphoma. Immunologically, peripheral B-cells show more functional IgD+ positive CD27 cells than usual.^{[citation needed]}

Prognosis

In the followup of 111 patients, most remained stable and event free. However, two patients developed IgM gammopathy 2 lung cancer; one developed cervical cancer and three developed non-Hodgkin's lymphoma. The possibility of developing a clonal proliferation, malignant lymphoma or secondary solid cancer led the authors to conclude not to classify PPBL as a benign pathology, as has been previously postulated but rather to recommend a careful and continued clinical and biological longterm follow-up.^[3]

References

1. Mitterer, M; Pescosta; et al. (July 1995). "Chronic active Epstein-Barr virus disease in a case of persistent polyclonal B-cell lymphocytosis". Br J Haematol. 90 (3): 526–31. doi:10.1111/j.1365-2141.1995.tb05579.x. PMID 7646989. S2CID 20485324.
2. Tonelli, S; Petronilla; et al. (October 2000). "Persistent polyclonal B lymphocytosis: morphological, immunological, cytogenetic and molecular analysis of an Italian case". Leuk. Res. 24 (10): 877–9. doi:10.1016/S0145-2126(00)00069-2. PMID 10996207.
3. Cornet, E; Lesesve JF; et al. (February 2009). "Long-term follow-up of 111 patients with persistent polyclonal B-cell lymphocytosis with binucleated lymphocytes". Leukemia. 23 (2): 419–22. doi:10.1038/leu.2008.208. PMC 2685812. PMID 18668130.