Chronic neutrophilic leukemia 2016: Update on diagnosis, molecular genetics, prognosis, and management

Defective migration and dysmorphology of neutrophil granulocytes in atypical chronic myeloid leukemia treated with ruxolitinib

BACKGROUND

The identification of pathologically altered neutrophil granulocyte migration patterns bears strong potential for surveillance and prognostic scoring of diseases. We recently identified a strong correlation between impaired neutrophil motility and the disease stage of myelodysplastic syndrome (MDS). Here, we apply this assay to study quantitively increased neutrophils of a patient suffering from a rare leukemia subtype, atypical chronic myeloid leukemia (aCML).

METHODS

A 69-year-old male was analyzed in this study. Besides routine analyses, we purified the patient's neutrophils from peripheral whole blood and studied their migration behavior using time-lapse video microscopy in a standardized assay. These live cell migration analyses also allowed for the quantification of cell morphology. Furthermore, the cells were stained for the markers CD15, CD16, fMLPR, CXCR1 and CXCR2.

RESULTS

Despite cytoreductive therapy with hydroxyurea, the patient's WBC and ANC were poorly controlled and severe dysgranulopoiesis with hypogranularity was observed. Neutrophils displayed strongly impaired migration when compared to healthy controls and migrating cells exhibited a more flattened-out morphology than control neutrophils. Because of a detected CSF3R (p.T618I) mutation and constitutional symptoms treatment with ruxolitinib was initiated. Within 1 week of ruxolitinib treatment, the cell shape normalized and remained indistinguishable from healthy control neutrophils. However, neutrophil migration did not improve over the course of ruxolitinib therapy but was strikingly altered shortly before a sinusitis with fever and bleeding from a gastric ulcer. Molecular work-up revealed that under ruxolitinib treatment, the CSF3R clone was depleted, yet the expansion of a NRAS mutated subclone was promoted.

CONCLUSION

These results demonstrate the usefulness of neutrophil migration analyses to uncover corresponding alterations of neutrophil migration in rare myeloid neoplasms. Furthermore, in addition to monitoring migration the determination of morphological features of live neutrophils might represent a useful tool to monitor the effectiveness of therapeutic approaches.

Efficacy of Ruxolitinib in Patients With Chronic Neutrophilic Leukemia and Atypical Chronic Myeloid Leukemia

PURPOSE

Colony-stimulating factor-3 receptor (CSF3R)-T618I is a recurrent activating mutation in chronic neutrophilic leukemia (CNL) and to a lesser extent in atypical chronic myeloid leukemia (aCML) resulting in constitutive JAK-STAT signaling. We sought to evaluate safety and efficacy of the JAK1/2 inhibitor ruxolitinib in patients with CNL and aCML, irrespective of CSF3R mutation status.

METHODS

We conducted a phase II study of ruxolitinib in 44 patients (21 CNL and 23 aCML). The primary end point was overall hematologic response rate (ORR) by the end of 6 continuous 28-day cycles for the first 25 patients enrolled. We considered a response as either partial (PR) or complete response (CR). We expanded accrual to 44 patients to increase our ability to evaluate secondary end points, including grade ≥ 3 adverse events, spleen volume, symptom assessment, genetic correlates of response, and 2-year survival.

RESULTS

ORR was 32% for the first 25 enrolled patients (8 PR [7 CNL and 1 aCML]). In the larger cohort of 44 patients, 35% had a response (11 PR [9 CNL and 2 aCML] and 4 CR [CNL]), and 50% had oncogenic CSF3R mutations. The mean absolute allele burden reduction of CSF3R-T618I after 6 cycles was greatest in the CR group, compared with the PR and no response groups. The most common cause of death is due to disease progression. Grade ≥ 3 anemia and thrombocytopenia were observed in 34% and 14% of patients, respectively. No serious adverse events attributed to ruxolitinib were observed.

CONCLUSION

Ruxolitinib was well tolerated and demonstrated an estimated response rate of 32%. Patients with a diagnosis of CNL and/or harboring CSF3R-T618I were most likely to respond.

Leukemia Cutis in Chronic Neutrophilic Leukemia Associated with Colony Stimulating Factor 3 Receptor Mutation: Clinical Severity Paralleled with Hematologic Abnormality

Cutaneous lesions of leukemia cutis (LC) by chronic neutrophilic leukemia (CNL) have been merely reported due to the rare occurrences of CNL. Furthermore cutaneous lesions in relation to clinical severity have been far less studied. A 70-year-old man presented with multiple violaceous papules and excoriations on both lower extremities. The diagnosis was LC based on histologic and laboratory evaluation and the origin was elaborated as CNL with the confirmation of colony stimulating factor 3 receptor (CSF3R) mutation. Interestingly, the patient presented clinical severity in a parallel manner to the hematologic abnormality. To the best of our knowledge, there has been no reported case of CSF3R confirmed LC in CNL featuring explicit skin eruption in relation to laboratory findings.

Septic Shock Predisposed by an Underlying Chronic Neutrophilic Leukemia with an Atypical Presentation; A Case Report

Background

Chronic neutrophilic leukemia (CNL) is an extremely rare myeloproliferative neoplasm (MPN). Due to the difficulty in its diagnosis, the diagnostic criterion was just recently revised in 2016. CNL is defined as: A clonal disorder with sustained primary neutrophilia, with normal neutrophil maturation, that does not meet other MPN criteria, as well as no identifiable mutations of the PDGFRA, PDGFRB or FGFR1 or PCM1-JAK2 genes, and, either, the presence of a CSF3R mutation, or if absent, the presence of sustained neutrophilia (> 3 months), splenomegaly and no other identifiable cause of reactive neutrophilia including the absence of a plasma cell neoplasm, or, if present, demonstration of myeloid cell clonality by cytogenetics. Only about 200 cases have been reported.

Case Presentation

We report a 61-year-old Caucasian male patient who initially presented with unexplained leukocytosis. An outpatient work-up was planned to rule out a myeloproliferative disorder but the patient was acutely admitted for MRSA septic shock. The patient was stabilized prior bone marrow work-up and was then diagnosed with an atypical type of CNL (JAK2 positive, CSF3R negative). The patient refused further treatment due to social circumstances and requested palliative care instead.

Conclusion

This case aims to present atypical findings of an extremely rare MPN. Even though a recent revision has been made to help in its diagnosis, atypical findings must still be considered. This, in turn, will help to further improve the current CNL diagnostic criteria.

Coexisting of bone marrow fibrosis, dysplasia and an X chromosomal abnormality in chronic neutrophilic leukemia with CSF3R mutation: a case report and literature review

Background

Chronic neutrophilic leukemia (CNL) is a rare myeloproliferative neoplasm (MPN) with less than 40 cases of patients being reported or clinically suspected meeting with 2008 World Health Organization (“WHO”) diagnostic criteria. The current diagnosis of CNL remains to exclude other diseases. Recently, a new biomarker of CSF3R mutations that is almost invariably present in CNL has been identified. There is no effective treatment for CNL, therefore prognosis of the disease is poor, but it may be attributed to the presence of both SETBP1 and CSF3R gene mutations. The presence or absence of CSF3R mutation did not affect survival, whereas a trend for shortened survival was observed among patients with SETBP1-mutation.

Case presentation

Here we report a 65-year old woman patient who presented with leukocytosis without sign of fever and tumors. Bone marrow aspirates showed a markedly hypercellular feature with 76%–92% myeloid and the dysplastic changes were found in about 7% of neutrophils cells. The bone marrow biopsy demonstrated marrow fibrosis with Gomori staining positive (+++~++++). Cytogenetic analysis showed 46,X,del (X) (q22). No molecular markers of BCR/ABL1 rearrangement (P210, P230, P190 and variably), JAK2V617F, FIP1L1-PDGFRA, TEL-PDGFRB, ZNF198-FGFR1 and SETBP1 mutations were identified, however, the CSF3R gene membrane proximal mutation (c.1853C > T/p.T618I sites) was detected by PCR techniques. The patient was diagnosed with CNL and died in about 2 months after disease diagnosis.

Conclusion

In clinical course, the CNL concurrently with severe bone marrow fibrosis and dysplastic features as well as X chromosomal abnormality may predict a worsening prognosis regardless of SETBP1 mutation status.

Recent Progress in Chronic Neutrophilic Leukemia and Atypical Chronic Myeloid Leukemia

PURPOSE OF REVIEW

We reviewed recent diagnostic and therapeutic progress in chronic neutrophilic leukemia (CNL) and atypical chronic myeloid leukemia (aCML). We summarized recent genetic data that may guide future efforts towards implementing risk-adapted therapy based on mutational profile and improving disease control and survival of affected patients.

RECENT FINDINGS

Recent genetic data in CNL and aCML prompted modifications to the World Health Organization (WHO) diagnostic criteria, which have improved our understanding of how CNL and aCML are different diseases despite sharing common findings of peripheral granulocytosis and marrow myeloid hyperplasia. The overlap of recurrently mutated genes between aCML and CMML support considering CSF3R-T618I mutated cases as a distinct entity, either as CNL or CNL with dysplasia. Ongoing preclinical and clinical studies will help to further inform the therapeutic approach to these diseases. Our understanding of CNL and aCML has greatly advanced over the last few years. This will improve clarity for the diagnosis of these diseases, provide a strategy for risk stratification, and guide risk-adapted therapy.

p53 Gene (NY-CO-13) Levels in Patients with Chronic Myeloid Leukemia: The Role of Imatinib and Nilotinib

The p53 gene is also known as tumor suppressor p53. The main functions of the p53 gene are an anticancer effect and cellular genomic stability via various pathways including activation of DNA repair, induction of apoptosis, and arresting of cell growth at the G1/S phase. Normally, the p53 gene is inactivated by mouse double minute 2 proteins (mdm2), but it is activated in chronic myeloid leukemia (CML). Tyrosine kinase inhibitors are effective chemotherapeutic agents in the management of CML. The purpose of the present study was to evaluate the differential effect of imatinib and nilotinib on p53 gene serum levels in patients with CML. A total number of 60 patients with chronic myeloid leukemia with ages ranging from 47 to 59 years were recruited from the Iraqi Hematology Center. They started with tyrosine kinase inhibitors as first-line chemotherapy. They were divided into two groups—Group A, 29 patients treated with imatinib and Group B, 31 patients treated with nilotinib—and compared with 28 healthy subjects for evaluation p53 serum levels regarding the selective effect of either imatinib or nilotinib. There were significantly (p < 0.01) high p53 gene serum levels in patients with CML (2.135 ± 1.44 ng/mL) compared to the control (0.142 ± 0.11 ng/mL). Patients with CML that were treated with either imatinib or nilotinib showed insignificant differences in most of the hematological profile (p > 0.05) whereas, p53 serum levels were high (3.22 ± 1.99 ng/mL) in nilotinib-treated patients and relatively low (1.18 ± 0.19 ng/mL) in imatinib-treated patients (p = 0.0001). Conclusions: Nilotinib is more effective than imatinib in raising p53 serum levels in patients with chronic myeloid leukemia.

Non-Classic Myeloproliferative Neoplasms: Are We Really Aware of These Rare Diseases in Daily Practice?

Chronic neutrophilic leukaemia (CNL), chronic eosinophilic leukaemia-not otherwise specified (CEL-NOS), and myeloproliferative neoplasm (MPN), unclassifiable are rare clonal diseases, known as ‘non-classic myeloproliferative neoplasms’. They are diagnosed largely based on exclusion of underlying reactive causes by patient history, physical examination, serological tests, and imaging studies. As well as peripheral blood testing, bone marrow examination is mandatory to exclude bone marrow infiltrating conditions such as multiple myeloma, acute leukaemias, etc. Today, molecular genetic classification should be undertaken to establish accurate diagnosis, in addition to the traditional morphological classification of MPN. Therefore, molecular genetic testing should take part in the diagnostic work-up of suspected patients with rare MPN. Of CNL patients, 90% (and in some datasets 100%) have mutations in CSF3R, which has led to the addition of this finding to the diagnostic criteria for CNL. The absence of rearrangements of FIP1L1/PDGFRA, PDGFRA, PDGFRB, FGFR1, and PCM1-JAK2 fusions should prompt consideration of a diagnosis of chronic eosinophilic leukaemia-not otherwise specified. MPN, unclassifiable, the least frequent type, is considered when an MPN has definite MPN features but does not meet diagnostic criteria for either the classic or the other non-classic MPN. They all share common symptoms and findings. Transformation to acute leukaemia is still a major clinical problem. Since no standard of care exists, the treatment approach is still symptomatic for all. This is an indicator that we really need disease-modifying drugs against initial diagnostic molecular markers, such as CSF3R inhibitors, which might change the natural history of these disorders. Therefore, participation in clinical trials is mandatory for this extremely rare patient population.

Targeted next-generation sequencing identifies clinically relevant mutations in patients with chronic neutrophilic leukemia at diagnosis and blast crisis

PURPOSE

Chronic neutrophilic leukemia is a rare form of myeloproliferative neoplasm characterized by mature neutrophil hyperleukocytosis. The majority of patients harbor somatic mutations of CSF3R gene and are potentially amenable to targeted therapy with JAK inhibitors. The incidence and clinical significance of additional mutations requires clarification.

MATERIALS AND METHODS

A next-generation sequencing approach for myeloid malignancy-associated mutations was applied to diagnostic and matched blast crisis samples from four chronic neutrophilic leukemia patients.

RESULTS

Next-generation sequencing confirmed the CSF3R T618I in all patients with identification of concurrent SRSF2, SETBP1, NRAS and CBL mutations at diagnosis. At blast crisis, clonal evolution was evidenced by an increased CSF3R T618I allele frequency and by loss or acquisition of CBL and NRAS mutations.

CONCLUSION

The diagnostic utility of a targeted next-generation sequencing approach was clearly demonstrated with the identification of additional mutations providing the potential for therapeutic stratification of chronic neutrophilic leukemia patients.

Genomics of Myeloproliferative Neoplasms

Myeloproliferative neoplasms (MPNs) are a group of related clonal hematologic disorders characterized by excess accumulation of one or more myeloid cell lineages and a tendency to transform to acute myeloid leukemia. Deregulated JAK2 signaling has emerged as the central phenotypic driver of BCR -ABL1-negative MPNs and a unifying therapeutic target. In addition, MPNs show unexpected layers of genetic complexity, with multiple abnormalities associated with disease progression, interactions between inherited factors and phenotype driver mutations, and effects related to the order in which mutations are acquired. Although morphology and clinical laboratory analysis continue to play an important role in defining these conditions, genomic analysis is providing a platform for better disease definition, more accurate diagnosis, direction of therapy, and refined prognostication. There is an emerging consensus with regard to many prognostic factors, but there is a clear need to synthesize genomic findings into robust, clinically actionable and widely accepted scoring systems as well as the need to standardize the laboratory methodologies that are used.

Genomics of chronic neutrophilic leukemia

Chronic neutrophilic leukemia (CNL) is a distinct myeloproliferative neoplasm with a high prevalence (>80%) of mutations in the colony-stimulating factor 3 receptor (CSF3R). These mutations activate the receptor, leading to the proliferation of neutrophils that are a hallmark of CNL. Recently, the World Health Organization guidelines have been updated to include CSF3R mutations as part of the diagnostic criteria for CNL. Because of the high prevalence of CSF3R mutations in CNL, it is tempting to think of this disease as being solely driven by this genetic lesion. However, recent additional genomic characterization demonstrates that CNL has much in common with other chronic myeloid malignancies at the genetic level, such as the clinically related diagnosis atypical chronic myeloid leukemia. These commonalities include mutations in SETBP1, spliceosome proteins (SRSF2, U2AF1), and epigenetic modifiers (TET2, ASXL1). Some of these same mutations also have been characterized as frequent events in clonal hematopoiesis of indeterminate potential, suggesting a more complex disease evolution than was previously understood and raising the possibility that an age-related clonal process of preleukemic cells could precede the development of CNL. The order of acquisition of CSF3R mutations relative to mutations in SETBP1, epigenetic modifiers, or the spliceosome has been determined only in isolated case reports; thus, further work is needed to understand the impact of mutation chronology on the clonal evolution and progression of CNL. Understanding the complete landscape and chronology of genomic events in CNL will help in the development of improved therapeutic strategies for this patient population.