What Does Atypical Chronic Lymphocytic Leukemia Really Mean? A Retrospective Morphological and Immunophenotypic Study

Atypical chronic lymphocytic leukemia (CLL) is still defined according to morphological criteria. However, deviance from the typical surface immunological profile suggests an atypical immunological-based CLL. A large cohort of patients with CLL was retrospectively evaluated aiming at assessing morphological (FAB criteria), immunophenotypical (two or more discordances from the typical profile), and clinical-biological features of atypical CLL. Compared to typical cases, morphologically atypical CLL showed a greater percentage of unmutated IgVH and CD38 positivity, and a higher expression of CD20. Immunophenotypically atypical CLL was characterized by more advanced clinical stages, higher expression of CD20, higher rate of FMC7, CD79b and CD49d positivity, and by an intermediate-high expression of membrane surface immunoglobulin, compared to typical cases. When patients were categorized based on immunophenotypic and morphologic concordance or discordance, no difference emerged. Finally, morphological features better discriminated patients' prognosis in terms of time-to-first treatment, while concordant atypical cases showed overall a worse prognosis. Discordant cases by immunophenotype and/or morphology did not identify specific prognostic groups. Whether-in the era of molecular markers used as prognostic indicators-it does make sense to focus on morphology and immunophenotype features in CLL is still matter of debate needing further research.

Measurable residual disease in chronic lymphocytic leukemia

Measurable residual disease (MRD) is defined as the presence of residual cancer cells after treatment in patients with clinically undetectable disease, who would otherwise be considered in complete remission. It is a highly sensitive parameter which indicates the disease burden and predicts survival in this setting of patients. In recent years, MRD has gained a role in many hematological malignancies as a surrogate endpoint for clinical trials: undetectable MRD has been correlated to longer progression free survival (PFS) and overall survival (OS). New drugs and combinations have been developed with the aim to achieve MRD negativity, which would indicate favorable prognosis. Different methods to measure MRD have also been devised, which include flow cytometry, polymerase chain reaction (PCR) and next generation sequencing (NGS), with different sensitivity and accuracy in evaluating deep remission after treatment. In this review, we will analyze the current recommendations for the detection of MRD, with particular focus on its role in Chronic Lymphocytic Leukemia (CLL), as well as the different detection methods. Moreover, we will discuss the results of clinical trials and the role of MRD in new therapeutic schemes with inhibitors and monoclonal antibodies. MRD is not currently used in the clinical practice to evaluate response to treatment, due to technical and economical limitations, but it's gaining more and more interest in trials settings, especially since the introduction of venetoclax. The use of MRD in trials will likely be followed by a broader practical application in the future. The aim of this work is to provide a reader-friendly summary of the state of art in the field, as MRD will soon become an accessible tool to evaluate our patients, predict their survival and guide physician's therapeutic choices and preferences.

Case report: Hematologic malignancies concomitant diagnosis of hairy cell leukemia and chronic lymphocytic leukemia: A rare association

A case of concomitant hairy cell leukemia (HCL) and chronic lymphocytic leukemia (CLL) in a 50- year-old man was reported. Flow cytometry and droplet digital PCR (ddPCR) were used to detect the B-Raf proto-oncogene (BRAF) V600E mutation. The HCL population was the predominant component. The patient was first treated with cladribine and then with rituximab and achieved HCL partial remission. Importantly, the high sensitivity of our flow cytometric approach allowed the detection of a small population "P3," in addition to the typical HCL and CLL clones. The P3 clone changed over time, from an HCL-like to a CLL-like immunophenotype. This case is added to the few other cases of synchronous HCL and CLL already reported in the literature and underlines the importance of analyzing chronic lymphoproliferative disorders by highly sensitive diagnostic techniques, like the multicolor flow cytometry and ddPCR, to evaluate the possible association between HCL and CLL at diagnosis.

SUBCUTANEOUS IMMUNOGLOBULINS IN CHRONIC LYMPHOCYTIC LEUKAEMIA WITH SECONDARY ANTIBODY DEFICIENCY. A MONOCENTRIC EXPERIENCE DURING COVID‐19 PANDEMICS

Secondary antibody deficiency (SAD) is a frequent manifestation of chronic lymphocytic leukemia (CLL) that increases the risk of infections. However, no formal guideline are available regarding the eligibility for prophylaxis or the delivery method, dosage, frequency of administration and duration of immunoglobulin replacement therapy (IgRT). The aim of this study was to assess the efficacy and safety of subcutaneous IgRT (SCIg) and its impact on quality of life (QoL) of CLL pts in the Covid‐19 era. Ten CLL pts with SAD were treated with subcutaneous IgRT (SCIg) at our institution between October 2019 and December 2020. Median age was 66 years and five patients had comorbidities. Seven patients were receiving therapy for CLL when treatment with SCIg was initiated. All pts received 10 g total dose hyaluronidase‐free SCIg independently from body weight. The IgG level and CD4/CD8, CD19 and CD16/56 lymphocytes subset were recorded at baseline and every 3 months. No patient experienced infectious events nor Covid‐19 mediated interstitial pneumonia while on SCIg therapy. All patients tolerated well the therapy and experienced an increase of IgG levels, which was then stable in time. We conclude that SCIg administration in CLL pts with SAD is efficacious and safe as infectious prophylaxis. This route of administration appears particularly advantageous in the Covid‐19 era, because of the self‐administration at home which results in improvement in the QoL and reduced treatment expenditures.

Monoclonal B-cell lymphocytosis and prostate cancer: incidence and effects of radiotherapy

Monoclonal B-cells lymphocytosis (MBL) is a benign condition that may precede chronic lymphocytic leukemia (CLL), not rarely present in peripheral blood of healthy elderly people, among which there is also a male prevalence. Though CLL has been associated with various types of solid tumors, including prostate cancer (PC), no data exist about the relationship between PC and MBL. We studied the frequency of CLL-like MBL clones in a group of 48 patients affected by PC and followed them during and after whole-pelvis radiotherapy (WPRT) treatment. We found four MBL clones (8.3%), two of which (4.2%) had a B-cell clonal count >1000 cells/µL (‘clinical MBL’). A single case (1.8%) of ‘low-count’ MBL occurred in a control group of 54 healthy males. Notably, normal B-lymphocytes were consistently affected by WPRT, while MBL clones were less radiosensitive. Our results suggest a possible association between ‘clinical’ MBL and PC and show a different impact of the radiation on monoclonal respect to normal B-cells, which could also imply a greater risk of clonal transformation.

Metabolic Syndrome, Insulin Resistance, Circadian Disruption, Antioxidants and Pancreatic Carcinoma: an Overview

The incidence and number of deaths caused by pancreatic tumours have been gradually rising, while the incidence and mortality of other common cancers have been declining. Risk factors for this malignant disease include cigarette smoking, family history of chronic pancreatitis, advancing age, male sex, diabetes mellitus, obesity, non-0 blood group, a high-fat diet, alcohol consumption and possibly Helicobacter pylori and hepatitis B virus infections. Metabolic diseases have become the leading cause of death in many countries. Our paper serves as a focused and updated discussion about the development of novel preventive strategies for this deadly disease. Abbreviations. ARE: antioxidant response element; COX-2: cyclooxygenase-2; IGFs: insulin-like growthfactors; IGF1R: IGF-1 receptor; MetS: metabolic syndrome; NAFLD: non-alcoholic fatty liver disease;NAFPD: non-alcoholic fatty pancreas disease; NASH: non-alcoholic steatohepatitis; NASP: non-alcoholic steatopancreatitis; PPARγ : peroxisome proliferator-activated receptor γ; PPARs: peroxisome proliferatoractivated receptors.

Monoclonal B-cell lymphocytosis

Monoclonal B-cell lymphocytosis (MBL) is an asymptomatic hematologic condition defined by the presence of a small (<5 x 10(9)/L) clonal B-cell population in the peripheral blood in the absence of lymph-node enlargement, cytopenias or autoimmune diseases. It is found in approximately 3-12% of normal persons depending on the accuracy of analytical techniques applied. According to the immunophenotypic profile of clonal B-cells, the majority of MBL cases (75%) are classified as chronic lymphocytic leukemia (CLL)-like. This form may progress into CLL at a rate of 1-2% per year. It is thought that CLL is always preceded by MBL. The remaining MBL cases are defined as atypical CLL-like (CD5+/CD20(bright)) and CD5(-) MBL. The MBL clone size is quite heterogenous. Accordingly, two forms of MBL are identified: i) high-count, or 'clinical' MBL, in which an evidence of lymphocytosis (<5 x 10(9)/L clonal B-cells) is seen, and ii) a low-count MBL, in which a normal leukocyte count is found and that is identified only in population-screening studies. Both forms of MBL may carry the cytogenetic abnormalities that are the hallmark of CLL, including 13q-, 17p- and trisomy 12. Consistent with the indolent phenotype of this condition, genetic lesions, such as TP53, ATM, NOTCH1 and SF3B1 mutations, usually associated with high-risk CLL, are rarely seen. Overall, no prognostic indicator of evolution of MBL to overt CLL has been found at present time. However, taking into account this possibility, a clinical and lab monitoring (at least annually), is recommended.

Fournier's Gangrene Complicating Hematologic Malignancies: a Case Report and Review of Licterature

Fournier's gangrene (FG) is a rare but severe necrotizing fasciitis of the external genitalia that may complicate the clinical course of hematologic malignancies and sometimes may be the first sign of the disease. The clinical course of FG is very aggressive and the mortality is still high despite the improvement in its management. Early recognition of FG and prompt appropriate treatment with surgical debridement and administration of antibiotics are the cornerstone of the management of this very severe disease. A review of the scientific literature focusing on the topic of FG complicating hematologic disorders is reported.

Regulatory T-cells in chronic lymphocytic leukemia: actor or innocent bystander?

Regulatory T (Treg) cells are now under extensive investigation in chronic lymphocytic leukemia (CLL). This small subset of T-cells has been, in fact, considered to be involved in the pathogenesis and progression of CLL. However, whether Treg dysregulation in CLL plays a key role or it rather represents a simple epiphenomenon is still matter of debate. In the former case, Treg cells could be appealing for targeting therapies. Finally, Treg cells have also been proposed as a prognostic indicator of the disease clinical course.

Response to SDF-1 defines a subset of CD38+/ZAP-70+ CLL patients with a common genetic signature and aggressive behavior (96.23)

Chronic lymphocytic leukemia (CLL), traditionally considered a disease of failed apoptosis, is now seen as characterized by a different propensity to grow according to microenvironmental signals. CD38 (surface receptor) and ZAP-70 (cytoplasmic molecule) independently predict unfavorable outcome in CLL patients. We reported that CD38 is a receptor mediating interactions with nurse-like cells (NLC) and transducing proliferation signals. The production by NLC of the attractant SDF-1α and the presence of ZAP-70 in CXCR4 pathway suggested that CD38 and ZAP-70 control CLL cell migration. We show that CD38+/ZAP-70+ patients feature enhanced ability to respond to SDF-1α. The functional link between the two molecules was confirmed by showing that i) CD38 engagement leads to ZAP-70 phosphorylation in CLL cells and in ad hoc modified B line expressing a ZAP-70-myc construct. Further, ii) CD38 signals are effective only in presence of ZAP-70, as seen in 22 molecularly characterized patients.

Lastly, a separation of the patient cohort based on migration, brought to the identification of 23 differentially expressed genes: 12 are involved in cell motility, migration and neoplastic transformation.

This work provides biological evidence explaining why the combination of CD38 and ZAP-70 in routine clinics results in a more efficient identification of CLL patients with aggressive disease.

Sponsors: CLL-GRF, AIRC, FIRMS.