Thomas Hofstra

Pharmacokinetic analysis of plasma-derived and recombinant F IX concentrates in previously treated patients with moderate or severe hemophilia B

BACKGROUND: Hemophilia B is an X‐linked bleeding disorder that affects approximately 1 in 25,000 males. Therapy for acute bleeding episodes consists of transfusions of plasma‐derived (pd‐F IX) or recombinant (r‐F IX) concentrates.

Nutritional deficiencies in iron overloaded patients with hemoglobinopathies

One of the hallmarks of both sickle cell disease (SCD) and thalassemia major (TM) is accelerated oxidative damage. Decreased antioxidant levels and increased oxidant stress biomarkers are found in both diseases. Although isolated vitamin deficiencies have been reported in TM and nontransfused SCD patients, a comprehensive evaluation of vitamin and trace mineral levels has never been performed in chronically transfused SCD or TM patients. As vitamins and trace minerals may be consumed as a result of chronic oxidative stress; we hypothesized that levels of these compounds would correlate with surrogates of iron overload, hemolysis, and inflammation in chronically transfused patients. Using a convenience sample of our group of chronically transfused patients we studied 43 patients with SCD (17 male, 26 female) and 24 patients with TM (13 male and 11 female). The age range for our patients varied from 1.5 to 31.4 years. Levels of vitamins A, thiamin, B6, B12, C, D, E as well as selenium, zinc, copper, and ceruloplasmin were measured. We found that 40–75% of the patients were deficient in A, C, D and selenium and 28–38% of the patients had low levels of B vitamins and folate. There was little association with iron overload, hemolysis, or inflammation. Although the precise mechanism of these deficiencies is unclear, they may contribute to the morbidity of chronically transfused hemoglobinopathy patients. Am. J. Hematol., 2009.

Tissue iron evaluation in chronically transfused children shows significant levels of iron loading at a very young age

Chronic blood transfusions start at a very young age in subjects with transfusion‐dependent anemias, the majority of whom have hereditary anemias. To understand how rapidly iron overload develops, we retrospectively reviewed 308 MRIs for evaluation of liver, pancreatic, or cardiac iron in 125 subjects less than 10 years old. Median age at first MRI evaluation was 6.0 years. Median liver iron concentrations in patients less than 3.5 years old were 14 and 13 mg/g dry weight in thalassemia major (TM) and Diamond–Blackfan anemia (DBA) patients, respectively. At time of first MRI, pancreatic iron was markedly elevated (> 100 Hz) in DBA patients, and cardiac iron ( R2* >50 Hz) was present in 5/112 subjects (4.5%), including a 2.5 years old subject with DBA. Five of 14 patients (38%) with congenital dyserythropoietic anemia (CDA) developed excess cardiac iron before their 10th birthday. Thus, clinically significant hepatic and cardiac iron accumulation occurs at an early age in patients on chronic transfusions, particularly in those with ineffective or absent erythropoiesis, such as DBA, CDA, and TM, who are at higher risk for iron cardiomyopathy. Performing MRI for iron evaluation in the liver, heart, and pancreas as early as feasible, particularly in those conditions in which there is suppressed bone marrow activity is very important in the management of iron loaded children in order to prescribe appropriate chelation to prevent long‐term sequelae. Am. J. Heamtol. 88:E283–E285, 2013.

Ferritin trends do not predict changes in total body iron in patients with transfusional iron overload

Ferritin levels and trends are widely used to manage iron overload and assess the efficacy of prescribed iron chelation in patients with transfusional iron loading. A retrospective cohort study was conducted in 134 patients with transfusion‐dependent anemia, over a period of up to 9 years. To determine whether the trends in ferritin adequately reflect the changes in total body iron, changes in ferritin between consecutive liver iron measurements by magnetic resonance imaging (MRI) were compared to changes in liver iron concentrations (LIC), a measure of total body iron. The time period between two consecutive LIC measurements was defined as a segment. Trends in ferritin were considered to predict the change in LIC within a segment if the change in one parameter was less than twofold that of the other, and was in the same direction. Using the exclusion criteria detailed in methods, the trends in ferritin were compared to changes in LIC in 358 segments. An agreement between ferritin trends and LIC changes was found in only 38% of the 358 segments examined. Furthermore, the change in ferritin was in opposite direction to that of LIC in 26% of the segments. Trends in ferritin were a worse predictor of changes in LIC in sickle cell disease than in thalassemia (P < 0.01). While ferritin is a convenient measure of iron status; ferritin trends were unable to predict changes in LIC in individual patients. Ferritin trends need to be interpreted with caution and confirmed by direct measurement of LIC. Am. J. Hematol. 89:391–394, 2014.

Vitamin D deficiency, cardiac iron and cardiac function in thalassaemia major

Vitamin D25‐OH and D1‐25OH levels were compared with cardiac R2* (1/T2*), left ventricular ejection fraction (LVEF), age, ferritin and liver iron in 24 thalassaemia major patients. Vitamin D25‐OH levels were reduced in 13/24 patients while vitamin D1‐25OH levels were often elevated. Vitamin D25‐OH levels decreased with age (r2 = 0·48) and with liver iron (r2 = 0·20). Cardiac R2* was inversely related with the ratio of D25‐OH to D1‐25OH levels (r2 = 0·42). LVEF was also proportional to the D25‐OH/D1‐25OH ratio (r2 = 0·49). Vitamin D deficiency may be associated with cardiac iron uptake and ventricular dysfunction in thalassaemia major patients.

Hemophagocytic lymphohistiocytosis in children with chronic granulomatous disease

Hemophagocytic lymphohistiocytosis (HLH) is characterized by fever, cytopenias, splenomegaly, and hemophagocytosis by macrophages activated by high cytokine levels. Chronic granulomatous disease (CGD) is characterized by recurrent infections, hyperinflammation, and excessive cytokine release. This may predispose patients with CGD to developing HLH during an infection. We conducted a retrospective review of patients with CGD, treated at our institution between 1999 and 2008. Three out of 17 patients developed HLH. Patients with CGD may be at increased risk for developing HLH. Remission of HLH was achieved after treatment with antimicrobials, steroids, and intravenous immunoglobulin This approach to treatment appears to be effective. Pediatr Blood Cancer 2011;56:460–462.

First case report of bloodstream infection by Rhizomucor pusillus in a child with hemophagocytic lymphohistiocytosis

We describe an unusual presentation of fatal infection due to Rhizomucor pusillus bloodstream infection in a 12-year old pediatric patient recently diagnosed with hemophagocytic lymphohistiocytosis. R. pusillus was isolated from one blood culture drawn on Day 11 of hospitalization.

Successful anti-CD20 monoclonal antibody treatment of severe autoimmune hemolytic anemia due to warm reactive IgM antibody in a child with common variable immunodeficiency

Autoimmune hemolytic anemia due to warm reactive IgM autoantibodies is unusual, severe, and often fails to respond to standard immunosuppressive therapies in both adults and children. A 6-year-old girl with common variable immunodeficiency had longstanding steroid dependent, splenectomy-unresponsive, warm IgM autoantibody-mediated autoimmune hemolytic anemia. Rituximab, a monoclonal antibody directed against CD20 antigen, was used to deplete B lymphocytes and reduce autoantibody production. She received a total of six doses of rituximab (375 mg/m2). Therapy was well tolerated, and B-lymphocytes were effectively depleted from the peripheral blood. The patient was completely tapered off glucocorticoids. The patient has remained off immunosuppressive agents for 16 months despite the return of B lymphocytes to the peripheral circulation. She continues to require IVIG. Early treatment with rituximab might be an option for patients with warm reactive IgM autoantibody-mediated autoimmune hemolytic anemia not responding to other treatments or experiencing untoward side effects from those treatments.