Granular lymphocyte proliferative disorders: a multicenter study of 20 cases

Area of Science:

• Hematology
• Oncology
• Immunology

Background:

• Granular lymphocyte proliferative disorders (GLPD) are rare conditions characterized by persistent granular lymphocytosis.
• Understanding the clinical behavior and biological features of GLPD is crucial for patient management.

Purpose of the Study:

• To report on a series of 20 patients diagnosed with GLPD.
• To analyze the clinical course, laboratory findings, immunophenotype, and cytogenetic abnormalities in GLPD patients.
• To investigate the correlation between clonal proliferation and clinical outcomes.

Main Methods:

• Inclusion criteria: persistent granular lymphocytosis (> or = 6 months) without a causative illness.
• Clinical evaluation, peripheral blood counts, bone marrow aspiration/biopsy, ultrastructural analysis, immunophenotyping (flow cytometry), chromosomal analysis, and T-cell receptor beta-chain gene rearrangement studies.
• In vitro culture of myeloid precursors and virological studies (HTLV-I/II).

Main Results:

• Most patients (17/20) had a nonprogressive course; two developed high-grade NHL, and one had progressive disease.
• 5-year actuarial survival probability was 85%.
• Clonal T-cell receptor beta-chain gene rearrangements were found in 78% of patients, predominantly in CD3+ cases (92%).
• Ultrastructural analysis revealed parallel tubular arrays in all cases.
• Chromosomal abnormalities were observed in 40% of analyzed patients.
• Decreased CFU-GM was noted in 5/6 patients.
• HTLV-I and II were negative.

Conclusions:

• GLPD typically follows an indolent clinical course with good survival rates.
• Clonal proliferation, assessed by T-cell receptor gene rearrangements, is common in GLPD but does not predict clinical outcome.
• The study highlights the heterogeneous lymphoid phenotype and cytogenetic findings in GLPD.