Prognostic Significance of Serial Determinations of LDH Levels in Primary (De Novo) Myelodysplastic Syndromes.

An increased lactate dehydrogenase (LDH) level at diagnosis is associated with a reduced probability of survival and an enhanced risk of AML development in primary (de novo) myelodysplastic syndromes (MDS). However, so far, little is known about the prognostic value of an increase in LDH levels during the follow up in these patients. We have serially determined LDH levels in 221 patients (102 males, 119 females) with de novo MDS (median age 70 years; FAB-types: RA, n=62; RARS, n=46; RAEB, n=48; RAEBT, n=36; CMML, n=29), and examined the prognostic value of LDH as a follow-up parameter. Confirming previous data, an elevated LDH level at diagnosis was found to be associated with a significantly increased probability of AML evolution and a significantly decreased probability of survival (p<0.05). In the follow up, an increase in LDH (from normal to elevated) was found to be associated with progression of MDS and AML evolution in most cases. Moreover, in those patients who progressed to AML, LDH levels were found to be significantly higher in the two three-months-periods preceding progression compared to the two initial three-months-periods examined (p<0.005). In most patients, the increase in LDH was accompanied or followed by other signs of disease progression, such as the occurrence of thrombocytopenia or an increase in blasts. Together, our data show that LDH can be employed as a prognostic follow-up variable in patients with MDS. In those patients in whom an increase in LDH is noted, a thorough re-evaluation of the progression-status of the disease including a bone marrow examination should be considered.