Low concentration of serum haptoglobin has impact on understanding complex pathophysiology in patients with acquired bone marrow failure syndromes

Abstract

To clarify whether measurement of serum haptoglobin (Hp) has impact on understanding pathophysiology in bone marrow failure (BMF) syndromes, we investigated concentrations of serum Hp by nephelometric procedure in 156 Japanese patients with BMF, including 54 aplastic anemia (AA), 50 paroxysmal nocturnal hemoglobinuria (PNH), and 52 myelodysplastic syndromes (MDS) patients. The frequencies with low concentrations of serum Hp (<42 mg/dL) in PNH patients (98.0%) were significantly higher than those in AA (27.8%; P < 0.0001) and MDS (38.5%; P < 0.0001) patients. In AA patients, white blood cell (WBC), absolute neutrophil, and platelet counts were significantly decreased in the group (n = 15) with low concentrations of serum Hp than in that (n = 39) with normal concentrations of it, and WBC counts were positively correlated with concentrations of serum Hp, suggesting that WBC counts may affect the concentrations. In MDS patients, hemoglobin concentrations and serum iron were significantly decreased and increased, respectively, in the group (n = 20) with low concentrations of serum Hp than in that (n = 32) with normal concentrations of it, and the values of serum iron were inversely correlated with concentrations of serum Hp, suggesting that ineffective erythropoiesis may affect the concentrations. Several AA and MDS patients with low concentrations of serum Hp had Coombs-negative autoimmune hemolytic anemia determined by immunoradiometric assay. In conclusion, several factors in conjunction with pathophysiology contribute to decrease of serum Hp in BMF.

Diagnostic screening of paroxysmal nocturnal hemoglobinuria: Prospective multicentric evaluation of the current medical indications

“…In contrast, new diagnostic algorithms are required for a more efficient screening of patients presenting with unexplained thrombosis in the absence of cytopenias. Further studies in which the utility of introducing sensitive parameters for hemolysis (e.g., haptoglobin levels (45)(46)(47)) in the diagnostic algorithm are investigated might contribute to better select for cases presenting with unexplained thrombosis in the absence of cytopenias, that should be screened for PNH. Most interestingly, our results also show that a depressed "normal" residual hematopoiesis coexists with the PNH clone in all patient groups, particularly among PNH 1 cases presenting with hemolysis, pointing out the potential utility of the evaluation of the PB counts of both GPI-deficient and GPI-normal cells for more efficient monitoring of PNH patients.…”

Natural history of paroxysmal nocturnal hemoglobinuria clones in patients presenting as aplastic anemia

“…There are now a few studies that have investigated the natural history of PNH clones in patients with AA (17, 18, 25, 26). The major difference between our study and previous reports is that the majority patients in this study received HiCy therapy (8).…”

Circulating Haptoglobin and Metabolic Syndrome in Renal Transplant Recipients

“…For example, hemolysis, which rapidly decreases circulating Hp concentrations 24 , is virtually absent in our stable RTR cohort and could thus not explain the higher mortality risk for subjects with lower circulating Hp. Other circumstances that are associated with decreased circulating Hp, include Hp genotype 7 and bone marrow failure 25 . However, adjustment for Hp genotype in the prospective analyses had no material effect.…”