Final results of a multicenter trial addressing role of CSF flow cytometric analysis in NHL patients at high risk for CNS dissemination

Ongoing challenge of optimal patient selection for CNS prophylaxis in patients with non-Hodgkin lymphoma

SUMMARY 

CNS relapse is a devastating and frequently lethal complication in patients with lymphoma, and selecting patients to receive CNS-directed prophylaxis is a common and frequently challenging decision for the clinician. Histologic subtype, anatomic location, molecular and clinical risk factors may all be used to stratify patients for CNS risk. In this paper we focus on these issues and attempt to provide practical guidance for the clinician in selecting which patients with lymphoma may benefit from CNS prophylaxis.

Detection of malignant B lymphocytes by PCR clonality assay using direct lysis of cerebrospinal fluid and low volume specimens

INTRODUCTION

The diagnosis of lymphoid malignancies is often challenging in paucicellular specimens. PCR may also be limited by insufficient cells for DNA isolation and incomplete coverage of gene rearrangements. This study aims to evaluate a PCR method for IgH clonality using direct cell lysates.

METHODS

PCR amplification used cell lysate from detergent-based lysis and BIOMED-2 primers. CSF specimens were tested for 20 patients with primary CNS lymphoma or systemic lymphoma suspected for CNS involvement. Cytology and flow cytometry analysis was performed in parallel with PCR.

RESULTS

Direct lysis produced a better yield than the column-based method for DNA isolation. PCR using lysate showed an efficiency of clonality detection from a minimum of 20 tumor cells. PCR clonality was found in nine of the 20 CSFs, and positive PCR was concordant with both cytology and flow cytometry in seven cases. There were two cases positive for PCR, but indeterminate for flow cytometry because of insufficient cell events. Of the eleven PCR-negative cases, two were considered as false negative, as flow cytometry showed positive for malignant cells. The PCR was also performed successfully with a specimen from the anterior chamber of the eye.

CONCLUSION

PCR clonality with direct cell lysis of CSF is feasible, and it may overcome the limitation of DNA isolation. This PCR method may be particularly useful for small volume and low cell CSF when flow cytometry is inconclusive.

Detection and outcome of occult leptomeningeal disease in diffuse large B-cell lymphoma and Burkitt lymphoma

The benefit of intrathecal therapy and systemic rituximab on the outcome of diffuse large B-cell lymphoma at risk of central nervous system disease is controversial. Furthermore, the effect of intrathecal treatment and rituximab in diffuse large B-cell and Burkitt lymphoma with occult leptomeningeal disease detected by flow cytometry at diagnosis is unknown. Untreated diffuse large B-cell (n=246) and Burkitt (n=80) lymphoma at clinical risk of central nervous system disease and having had pre-treatment cerebrospinal fluid were analyzed by flow cytometry and cytology. Spinal fluid involvement was detected by flow cytometry alone (occult) in 33 (13%) diffuse large B-cell and 9 (11%) Burkitt lymphoma patients, and detected by cytology in 11 (4.5%) and 5 (6%) patients, respectively. Diffuse large B-cell lymphoma with occult spinal fluid involvement had poorer survival (P=0.0001) and freedom from central nervous system relapse (P<0.0001) compared to negative cases. Burkitt lymphoma with occult spinal fluid involvement had an inferior freedom from central nervous system relapse (P=0.026) but not survival. The amount of intrathecal chemotherapy was quantitatively associated with survival in diffuse large B-cell lymphoma with (P=0.02) and without (P=0.001) occult spinal fluid involvement. However, progression of systemic disease and not control of central nervous system disease was the principal cause of treatment failure. In diffuse large B-cell lymphoma, systemic rituximab was associated with improved freedom from central nervous system relapse (P=0.003) but not with survival. Our results suggest that patients at risk of central nervous system disease should be evaluated by flow cytometry and that intrathecal prophylaxis/therapy is beneficial.

Flow cytometric analysis of cerebrospinal fluid has low diagnostic yield in samples without atypical morphology or prior history of hematologic malignancy

OBJECTIVES

To identify pretest characteristics of cerebrospinal fluid (CSF) specimens that will allow the rational use of flow cytometric analysis (FCA) in the diagnosis of hematologic malignancy.

METHODS

Retrospective data were collected on 501 consecutive CSF samples submitted for FCA.

RESULTS

A positive diagnosis of hematologic malignancy was made in 41 specimens (8.2%). Blasts or atypical lymphocytes were noted on Wright-stained slides in 98% of FCA-positive specimens (40/41), and a history of a hematologic malignancy was present in 89% of specimens (34/38). All FCA-positive specimens had atypical morphology or history of hematologic malignancy. Four hundred six specimens (81%) were FCA negative. Of FCA-negative specimens, 7% (30/406) had atypical morphology, and 3% (12/404) had future central nervous system involvement seen within 30 days.

CONCLUSIONS

These data support a policy in which FCA of CSF is actively discouraged unless atypical lymphocytes or blasts are seen or a history of hematologic malignancy is present.

Factors predictive of relapse of acute leukemia in children after allogeneic hematopoietic cell transplantation

The presence of minimal residual disease (MRD) before transplantation is the most important prognostic risk factor predictive of post-transplantation relapse in hematologic malignancies. However, MRD alone does not adequately predict relapse in all patients. To improve upon the ability to identify patients likely to relapse, we evaluated risk factors, in addition to MRD, that may be associated with development of post-transplantation relapse. In this single institution, retrospective cohort study of children with acute leukemia or myelodysplastic syndrome who had undergone a first allogeneic transplantation and had pretransplantation MRD evaluation, 40 of 93 patients (43%) experienced relapse. Univariate analysis demonstrated that African American race, high initial white blood cell count, central nervous system (CNS) disease at diagnosis, short first complete remission, nonmyeloablative (NMA) conditioning, lack of remission, and MRD before transplantation were associated with worse relapse-free survival (RFS). In a Cox multivariable analysis, CNS disease (P = .009), lack of remission (P = .01), and NMA conditioning (P = .04) were independently associated with inferior RFS. Among those in a morphologic complete remission who underwent a myeloablative transplantation, having both CNS disease at diagnosis (specifically in acute lymphoblastic leukemia) and MRD positivity was an independent risk factor predictive of relapse, which has not been previously reported. Results from our study support the existence of risk factors complimentary to pretransplantation MRD. Validation in a larger independent homogenous cohort is needed to develop a prognostic tool for clinical use to predict post-transplantation relapse.

Contribution of cerebrospinal fluid sCD19 levels to the detection of CNS lymphoma and its impact on disease outcome

Flow cytometry (FCM) is more sensitive than conventional cytology for detection of occult leptomeningeal lymphoma; however, some FCM-negative patients show central nervous system (CNS) recurrence. Here, we evaluated the cerebrospinal fluid (CSF) levels of 13 B-cell-associated markers and their contribution to the diagnosis of CNS lymphoma in 91 diffuse large B-cell lymphomas (DLBCL) and 22 Burkitt lymphomas (BLs). From all markers tested, CD19 was the most informative. Thus, higher soluble CD19 (sCD19) levels were associated with a greater frequency of neurological symptoms in DLBCL and BL and with parenchymal CNS lymphoma in DLBCL; sCD19 emerged as a powerful predictor of event-free and overall survival in DLBCL and BL, particularly when combined with FCM detection of CNS disease. These results support the utility of combined FCM detection of lymphoma cells and assessment of sCD19 levels in CSF, for more accurate identification of CNS disease in DLBCL and BL patients.

Primary testicular lymphoma

Primary testicular lymphoma (PTL) is a rare, clinically aggressive form of extranodal lymphoma. The vast majority of cases are histologically diffuse large B-cell lymphoma, but rarer subtypes are clinically important and must be recognized. In this review, we discuss the incidence, clinical presentation, and prognostic factors of PTL and present a summary of the recent advances in our understanding of its pathophysiology, which may account for the characteristic clinical features. Although outcomes for patients with PTL have historically been poor, significant gains have been made with the successive addition of radiotherapy (RT), full-course anthracycline-based chemotherapy, rituximab and central nervous system–directed prophylaxis. We describe the larger retrospective series and prospective clinical trials and critically examine the role of RT. Although rituximab plus cyclophosphamide, doxorubicin, vincristine, and prednisone given every 21 days with intrathecal methotrexate and locoregional RT is the current international standard of care, a substantial minority of patients progress, representing an unmet medical need. Finally, we discuss new treatment approaches and recent discoveries that may translate into improved outcomes for patients with PTL.

The risk of CNS involvement in aggressive lymphomas in the rituximab era

The risk of CNS dissemination and CNS prophylaxis strategies in aggressive non-Hodgkin lymphoma (NHL) is still debated. CNS dissemination is a rare but fatal event. A CNS prophylaxis is common for Burkitt and B-cell lymphoblastic lymphoma; however, in other NHLs, prophylactic treatments are not systematically warranted. Current risk models showed low sensitivity in predicting CNS involvement, implying overtreatment in roughly 70% of high-risk patients. Risk models in the rituximab era were modulated for the detection of occult CNS disease at diagnosis using flow cytometry. The optimal regimen for CNS prophylaxis in aggressive lymphoma patients has not been established thus far and should be modulated at different levels of 'intensity' such as standard intrathecal chemotherapy, 'active' intrathecal chemotherapy with liposomal cytarabine or more aggressive systemic treatment with high doses of drugs having good CNS bioavailability reserved for patients who are truly at high risk of CNS dissemination.

Immune cell subtyping in the cerebrospinal fluid of patients with neurological diseases

The analysis of cerebrospinal fluid (CSF) with the assessment of CSF cell counts and proteins is an important method in the diagnostic workup of neurological diseases. As an addition to this standard approach, we here present data on the distribution of CSF immune cell subsets in common neurological diseases, and provide reference values along with cases of rare neurological diseases. CD4+ and CD8+ T cells, the CD4/CD8 ratio, B cells, plasmablasts, monocytes and NK cells in the CSF of 319 patients with inflammatory or non-inflammatory neurological diseases were analysed by seven-color flow cytometry. Diagnoses included headache, idiopathic intracranial hypertension, Guillain-Barré syndrome, multiple sclerosis, Lyme neuroborreliosis, bacterial and viral meningitis, human immunodeficiency virus (HIV) infection, stroke, and CNS malignancies, among others. T cells were the predominant population in the CSF with CD4+ T cells being more prevalent than CD8+ T cells. Mostly in HIV patients, and under other conditions of immunosuppression, CD4+ and CD8+ T cells were significantly altered and the CD4/CD8 ratio reduced. B cells and plasmablasts could hardly be detected in non-inflammatory diseases but were consistently elevated in inflammatory diseases. Monocytes were reduced in neuroinflammation and showed a negative correlation with B cells. NK cells were slightly elevated in neuroinflammation. Both monocytes and NK cells were slightly elevated in CNS malignancies. The analysis of immune cell subsets in the CSF adds valuable information to clinicians and is a promising tool for the differential diagnosis of neurological diseases.

Guideline on the prevention of secondary central nervous system lymphoma: British Committee for Standards in Haematology

The guideline group was selected to be representative of UK-based medical experts. Ovid MEDLINE, EMBASE and NCBI Pubmed were searched systematically for publications in English from 1980 to 2012 using the MeSH subheading 'lymphoma, CNS', 'lymphoma, central nervous system', 'lymphoma, high grade', 'lymphoma, Burkitt's', 'lymphoma, lymphoblastic' and 'lymphoma, diffuse large B cell' as keywords, as well as all subheadings. The writing group produced the draft guideline, which was subsequently revised by consensus by members of the Haemato-oncology Task Force of the British Committee for Standards in Haematology (BCSH). The guideline was then reviewed by a sounding board of ~50 UK haematologists, the BCSH and the British Society for Haematology (BSH) Committee and comments incorporated where appropriate. The 'GRADE' system was used to quote levels and grades of evidence, details of which can be found in Appendix I. The objective of this guideline is to provide healthcare professionals with clear guidance on the optimal prevention of secondary central nervous system (CNS) lymphoma. The guidance may not be appropriate to patients of all lymphoma sub-types and in all cases individual patient circumstances may dictate an alternative approach. Acronyms are defined at time of first use.

Diagnostic strategies to investigate cerebrospinal fluid involvement in haematological malignancies

Central nervous system (CNS) involvement is a fatal complication of certain haematological malignancies with an incidence as high as 25% in specific leukaemia/lymphoma subtypes. It is often accompanied by 'occult' cerebrospinal fluid (CSF) involvement at diagnosis, which is frequently missed by conventional cytology examination. Unfortunately, a diagnostic gold standard is yet unavailable since CSF morphology may be negative for malignant cells in up to 45% of patients with suspected meningeal involvement. New technologies such as flow cytometry, molecular genetics and newer biomarkers may improve sensitivity and specificity facilitating the diagnosis of CNS involvement as well as effective prophylaxis and successful treatment.