Several studies have suggested that an increased peripheral blood absolute lymphocyte count (ALC) at day 15 after ASCT is associated with improved survival and decreased relapse rate. Recently, the ratio of ALC to the absolute monocyte count (AMC) (Lymphocyte:Monocyte Ratio; LMR) has been described as a strong prognostic factor at time of diagnosis in patients with various lymphoid malignancies. In most reports, a LMR cut-off value of less than 1.1 indicates patients who have a worse outcome.
To evaluate the prognostic impact of the LMR at start of conditioning regimen and at day 15 post ASCT in patients with a diagnosis of lymphoma and myeloma
We retrospectively reviewed the medical records of 121 adult patients with a diagnosis of lymphoma or myeloma who underwent ASCT at Hospital Israelita Albert Einstein from January, 2005 to July, 2012. Lymphocyte count was registered at the 15th day after SCT and lymphopenia was defined as an ALC< 500 at this time point. The LMR was calculated considering the ALC and AMC at baseline (start of conditioning regimen) and at day 15 post-ASCT. Overall survival (OS) was estimated from the time of transplant until death, with surviving patients censored at last follow-up. Variables entered into the multivariate Cox analysis were those with a p-value <0.10 in the univariate analysis. Statistical analysis was performed with STATA (v11.0) and alfa error was defined as 5%.
The majority of patients were male (69%) and the median age was 58 years old (range: 3–76). Peripheral stem cell harvest was the main source of cells (61%). Diagnosis included multiple myeloma (49%), non-Hodgkin’s lymphoma (45%) and Hodgkin’s lymphoma (6%). The median LMR at start of conditioning regimen was 0.60, while at day 15 it was 1.75. Seventy-three percent of patients at start of conditioning had a LMR <1.1, while the same percentage at day 15 was 25%. Considering LMR cut-off at 1.1, an increased LMR value at baseline was associated with improved survival (HR 0.44; p=0.03), while it was not predictive at day 15 (HR=0.99; p=0.99). At 2 years, the OS was 48% for patients with a LMR<1.1 at start of conditioning regimen versus 76% for those patients with a LMR ≥1.1 (p=0.03 by logrank). In a multivariate Cox analysis considering age, sex, diagnosis, day 15 lymphopenia and baseline LMR, baseline LMR remained an independent variable associated with survival (HR=0.40, p=0.044), while day15 lymphopenia had no prognostic value (HR=0.80. p=0.56).
In our cohort of patients, the presence of an increased LMR at baseline before start of conditioning regimen identified a subgroup of patients who had a very good outcome. These results should be validated in other cohorts. Strategies to improve outcome for patients who present with decreased LMR and a better understanding of the role of LMR should be the focus of future studies.
No relevant conflicts of interest to declare.
Asterisk with author names denotes non-ASH members.