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Chapter 32

Koulieris et al. [720] studied the prognostic significance of IgM HLC in 31 WM patients at diagnosis. The median involved/uninvolved IgM HLC ratio was significantly higher in WM patients requiring treatment (n=24) compared with patients not requiring treatment (n=7) (185.7 vs. 13.45; p=0.023). Leleu et al. [670] reported similar data: the median involved/uninvolved HLC ratio was significantly higher in progressing symptomatic patients compared with asymptomatic patients (p=0.014). Patients with a higher involved/uninvolved HLC ratio (>median) had a significantly shorter time to treatment than those patients with a lower HLC ratio Figure 32.8A.

Koulieris et al. [720] also reported a correlation between the IgM HLC ratio and bone marrow infiltration (p=0.029) and time to first treatment (p=0.003); they proposed a risk stratification model that identified 3 prognostic groups with respect to survival. This model comprised 3 risk factors: involved/uninvolved IgM HLC ratio (>median); β2-microglobulin (>5.5 mg/L); and abnormal lactate dehydrogenase (LDH) (Figure 32.8B).

In a subsequent, larger study, Koulieris et al. [722] studied the prognostic significance of systemic hypogammaglobulinaemia and HLC pair suppression in 70 WM patients at diagnosis. HLC pair suppression (defined as IgMκ or IgMλ <0.1 g/L) was present in 26% (18/70) patients; whilst systemic hypogammaglobulinaemia (defined as IgG <7 g/L and/or IgA <0.7 g/L), was present in 49% (34/70) of patients. During follow-up (median 37 months), 48/70 patients were or became symptomatic and 16/70 died. Neither systemic hypogammaglobulinaemia nor HLC pair suppression at diagnosis correlated with time to first treatment (p=0.358) or overall survival (p=0.874). Conversely, Murillo-Florez et al. [723] found that relapsed/refractory WM patients had a mean uninvolved HLC concentration that was lower than the patients who did not relapse (0.29 vs. 0.52 g/L; p=0.04). Therefore, the prognostic utility of HLC pair measurement in WM has yet to be established.

Andrade-Campos et al. [950] evaluated the prognostic value of HLC pair suppression in 32 patients with asymptomatic WM. At diagnosis, an involved/uninvolved HLC ratio >62 identified a subset of patients with a shorter time to progression (108 vs. 133 months, p=0.033), and the authors concluded that HLC pair suppression was the major contributor to the prognostic value of the Hevylite assay.

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