Increased blood viscosity and red blood cell aggregation in a patient with sickle cell anemia and smoldering myeloma
Authors: Nathalie Lemonne, Philippe Connes, Marc Romana, Jens Vent‐Schmidt, Véronique Bourhis, Yann Lamarre, Maryse Etienne‐Julan
Journal: American Journal of Hematology (2012)

We report the case of an asymptomatic patient with sickle cell anemia (SCA) and multiple myeloma (MM), who developed repeated painful vaso-occlusive crises (VOC) accordingly to its blood rheological profile. A 36 years-old Guadeloupean male with SCA recently consulted to the Sickle Cell Center of Guadeloupe for severe and repeated VOC. In the past, this patient was mostly asymptomatic: no hospitalized VOC since birth, history of ankle ulcers, and one post-surgical acute chest syndrome six years ago. Two months later, the diagnosis of smoldering myeloma was done with IgA monoclonal component, plasmocytosis at 15%, and locus p53 trisomy on chromosom 17. No proteinuria and no evidence of end-organ damage were observed: hemoglobin level was 8.5 g/dL (+1 g/dL above baseline), no bone lesion at X-rays and MRI, normocalcemia and normal blood creatinin level. Lactate dehydrogenase level was 1,500 UI/L and hematocrit was 25% (+4% above baseline level) in agreement with the crisis state associated with hemoconcentration and suspected blood hyper-viscosity. After obtaining written informed consent, we analyzed the blood rheological profile [1] and compared the values to standard values published in patients with SCA or sickle hemoglobin-C disease (SC disease), and healthy subjects (Table I) [2]. Blood viscosity of the patient with SCA/MM was markedly elevated (Table I) and far beyond the mean values found in SCA patients at steady state or in healthy subjects whereas hematocrit was in the normal SCA patients range [2]. Usually, blood viscosity of SCA patients is decreased under values of healthy subjects because of chronic anemia. However, blood viscosity of this SCA/MM patient was higher than that of patients with SC disease. Increased blood viscosity is a risk factor for acute chest syndrome in SC disease and for painful VOC in SCA [3]. The blood hyper-viscosity of our patient results from wide hemorheological alterations, which may impair microcirculatory blood flow. The reduced RBC deformability value in our SCA/MM patient was comparable to standard SCA values (Table I). In contrast, RBC aggregation was far beyond the RBC aggregation usually observed in SCA or SC disease, and reached higher values than those detected in healthy subjects. This result was unexpected since low RBC deformability usually results in low RBC aggregation [2, 3]. At moderate shear rate (90 sec−1), most part of RBC aggregates is dispersed in healthy controls. But, in case of SCA and SC disease, the strength needed to disrupt RBC aggregates is around 320–380 sec−1 (375 sec−1 in our patient), meaning that when blood viscosity was measured (at 90 sec−1), RBC aggregates were still present and impacted on blood viscosity. The plasma fibrinogen level of our clinical case was not pathologic (2.30 g/L) and does not explain RBC hyper-aggregation. Mixing plasma from our patient with RBCs from another SCA patient with no MM (control) and with the same blood phenotypes (same A, B, O, Rh, and Duffy group) lead to a rise in RBC aggregation whereas mixing control plasma with SCA/MM RBCs decreased RBC aggregation (data not shown). Indeed, it seems that plasma factors, other than fibrinogen, could be involved in the RBC hyper-aggregation of the SCA/MM patient. Increased level of IgA in blood could have promoted RBC hyper-aggregation, as it may be the case in hepathic cirrhosis [4]. Intra-venous hyper-hydration has been sufficient to offset painful VOC in the SCA/MM patient. Our observation suggests that hyper-hydration of patients with both SCA and MM could probably be a good strategy to normalize blood-hyperviscosity and treat acute painful complications. As for other smoldering MM, this patient is regularly clinically monitored and the acute VOC manifestations caused by its SCA status are managed with hyper-hydration when they occur. If hyper-hydration would become inefficient, the question of the use of plasmapheresis or Lenalidomid medication to decrease IgA level and normalize blood viscosity should be raised. Nathalie Lemonne*, Philippe Connes , Marc Romana , Jens Vent-Schmidt , Véronique Bourhis , Yann Lamarre , Maryse Etienne-Julan*, * Unité Transversale de la Drépanocytose, Centre Hospitalier et Universitaire de Pointe-à-Pitre, Pointe-à-Pitre, France, Inserm U665, Pointe-à-Pitre, F-97159 Guadeloupe, Université des Antilles et de la Guyane, Pointe-à-Pitre, F-97157, France, Service d'Onco-hématologie, Centre Hospitalier et Universitaire de Pointe-à-Pitre, Pointe-à-Pitre, France.