de novo interstitial deletions at the 11q23.3-q24.2 region

Patients with Chromosome 11q Deletions Are Characterized by Inborn Errors of Immunity Involving both B and T Lymphocytes

Disorders of the long arm of chromosome 11 (11q) are rare and involve various chromosomal regions. Patients with 11q disorders, including Jacobsen syndrome, often present with a susceptibility for bacterial and prolonged viral and fungal infections partially explained by hypogammaglobulinemia. Additional T lymphocyte or granular neutrophil dysfunction may also be present. In order to evaluate infectious burden and immunological function in patients with 11q disorders, we studied a cohort of 14 patients with 11q deletions and duplications. Clinically, 12 patients exhibited prolonged and repetitive respiratory tract infections, frequently requiring (prophylactic) antibiotic treatment (n = 7), ear-tube placement (n = 9), or use of inhalers (n = 5). Complicated varicella infections (n = 5), chronic eczema (n = 6), warts (n = 2), and chronic fungal infections (n = 4) were reported. Six patients were on immunoglobulin replacement therapy. We observed a high prevalence of low B lymphocyte counts (n = 8), decreased T lymphocyte counts (n = 5) and abnormal T lymphocyte function (n = 12). Granulocyte function was abnormal in 29% without a clinical phenotype. Immunodeficiency was found in patients with terminal and interstitial 11q deletions and in one patient with terminal 11q duplication. Genetically, FLI1 and ETS1 are seen as causative for the immunodeficiency, but these genes were deleted nor duplicated in 4 of our 14 patients. Alternative candidate genes on 11q may have a role in immune dysregulation. In conclusion, we present evidence that inborn errors of immunity are present in patients with 11q disorders leading to clinically relevant infections. Therefore, broad immunological screening and necessary treatment is of importance in this patient group.

Prognostic Significance of Mixed-Lineage Leukemia (MLL) Gene Detected by Real-Time Fluorescence Quantitative PCR Assay in Acute Myeloid Leukemia

Background

The overall prognosis of acute myeloid leukemia (AML) patients with mixed-lineage leukemia (MLL) gene-positivity is unfavorable. In this study, we evaluated the expression levels of the MLL gene in AML patients.

Material/Methods

We enrolled 68 MLL gene-positive patients out of 433 newly diagnosed AML patients, and 216 bone marrow samples were collected. Real-time fluorescence quantitative PCR (RQ-PCR) was used to precisely detect the expression levels of the MLL gene.

Results

We divided 41 patients into 2 groups according to the variation of MRD (minimal residual disease) level of the MLL gene. Group 1 (n=22) had a rapid reduction of MRD level to ≤10⁻⁴ in all samples collected in the first 3 chemotherapy cycles, while group 2 (n=19) had MRD levels constantly >10⁻⁴ in all samples collected in the first 3 chemotherapy cycles. Group 1 had a significantly better overall survival (p=0.001) and event-free survival (p=0.001) compared to group 2. Moreover, the patients with >10⁻⁴ MRD level before the start of HSCT (hematopoietic stem cell transplantation) had worse prognosis and higher risk of relapse compared to patients with ≤10⁻⁴ before the start of HSCT.

Conclusions

We found that a rapid reduction of MRD level to ≤10⁻⁴ appears to be a prerequisite for better overall survival and event-free survival during the treatment of AML. The MRD levels detected by RQ-PCR were basically in line with the clinical outcome and may be of great importance in guiding early allogeneic HSCT (allo-HSCT) treatment.