Luigi F. Bertoli

Iron overload in African Americans

PURPOSE Iron overload unexplained by dietary or medicinal iron excess, transfusion, or sideroblastic anemia has been described infrequently in Americans of African descent. The purpose of this study was to characterize iron overload attributable to excessive iron absorption in African Americans. PATIENTS AND METHODS In a community hematology and medical oncology practice during the interval 1990 to 1993, we identified and evaluated a series of cases comprised of 6 men and 1 woman, with a mean age of 55 +/- 14 (SD) years (range 33 to 69). Data on clinical features, serum iron parameters, liver and body iron stores, evaluations of anemia, human leukocyte antigen (HLA) typing, and family studies were analyzed. RESULTS Among our patients, the serum iron parameters were: iron concentration 26 +/- 13 mumol/L, transferrin saturation 59 +/- 21%, and ferritin concentration 1,588 +/- 1,053 micrograms/L. Clinical abnormalities observed included weakness and fatigue, decreased libido and impotence, hepatopathy, arthropathy, diabetes mellitus, hypogonadotrophic hypogonadism, and hyperpigmentation. Hepatic parenchymal cell iron deposits were increased in each of the 6 patients studied, and Kupffer cell iron deposits were prominent in 4. The occurrence of iron overload was verified by liver iron quantification and therapeutic phlebotomy. Four subjects had alpha-thalassemia minor; 2 others had hemoglobin S and C traits. No proband had HLA-A3 positivity. Four probands had other family members with iron overload. CONCLUSIONS In comparison with Caucasians with hemochromatosis, our patients have slightly lower mean values of serum iron concentration and transferrin saturation, more Kupffer cell iron deposits, a higher incidence of thalassemia and hemoglobinopathy, and infrequent positivity for HLA-A3. Iron overload in African Americans appears to be more similar to that in certain sub-Saharan African natives than to hemochromatosis.

Intravenous iron dextran therapy in patients with iron deficiency and normal renal function who failed to respond to or did not tolerate oral iron supplementation.

PURPOSE To evaluate the safety and effectiveness of using 500-mg doses of iron as intravenous iron dextran after premedication with diphenhydramine, cimetidine, and dexamethasone. SUBJECTS AND METHODS We treated 135 iron-deficient adults (26 men, 109 women) with normal renal function (serum creatinine level </=1.5 mg/dL or blood urea nitrogen level </=26 mg/dL) who could not be treated adequately with oral iron supplements due to gastrointestinal symptoms (59%), inadequate hematologic response (39%), severe anemia (19%), or noncompliance (4%). Some patients had more than one reason for treatment. Resolution of iron deficiency was defined as the restoration of transferrin saturation, serum ferritin level, anemia, and abnormal erythrocyte indexes to normal or baseline values. RESULTS Before treatment with iron dextran, patients had a mean (+/- SD) transferrin saturation of 8% +/- 5%, a median serum ferritin level of 11 ng/mL, and a mean hemoglobin level of 10 +/- 2 g/dL. Ninety-two percent were anemic; 60% had unrecognized or untreated causes of anemia other than iron deficiency. We administered 285 iron dextran infusions (median 2, mean 2 infusions per patient; range 1 to 7). Eighty-seven percent of patients had no adverse reaction; 13% had mild reactions, especially arthralgias and myalgias. No patient had an anaphylaxis-like reaction. Fifty-four (40%) patients had resolution of iron deficiency, 34 (25%) continue to receive therapy, 36 (27%) returned to the care of their primary physician, and 11 (8%) died before iron repletion could be achieved. CONCLUSIONS Iron-deficient adults with normal renal function who cannot be treated adequately with oral iron supplements can be treated effectively and safely with this intravenous iron dextran regimen.

Peripheral blood erythrocyte parameters in hemochromatosis: Evidence for increased erythrocyte hemoglobin content☆☆☆★

We studied peripheral blood erythrocyte parameters and HFE genotypes in 94 hemochromatosis probands and 132 white, normal control subjects. Mean red blood cell counts in probands and control subjects were not significantly different. However, mean values of hemoglobin, hematocrit, mean corpuscular volume (MCV), mean corpuscular hemoglobin (MCH), and mean corpuscular hemoglobin concentration (MCHC) were significantly higher in C282Y/C282Y probands (n = 60) than in wild-type control subjects (n = 65). Probands with other HFE genotypes also had increased mean erythrocyte parameters (other than red blood cell count). Peripheral blood smears prepared before therapeutic phlebotomy revealed that erythrocytes in many probands had increased diameters and were well filled with hemoglobin. Erythrocyte parameters were similar in C282Y/C282Y probands with and without hepatomegaly, elevated serum concentrations of hepatic enzymes, hepatic cirrhosis, diabetes mellitus, arthropathy, or hypogonadism. Among C282Y/C282Y probands, significantly greater values of MCV (but not other erythrocyte parameters) occurred among those who had transferrin saturation values of 75% or greater or iron overload at diagnosis. After iron depletion, the mean MCV, MCH, and MCHC values of C282Y/C282Y probands decreased but remained significantly greater than values in wild-type control subjects. Mean values of prephlebotomy MCH and MCHC concentrations were lower in HLA-A3-positive than in HLA-A3-negative C282Y/C282Y probands. We conclude that increased values of mean hemoglobin, hematocrit, MCV, MCH, and MCHC in hemochromatosis probands are caused primarily by increased iron uptake and hemoglobin synthesis by immature erythroid cells. Mechanisms of iron uptake by erythrocytes that could explain these results are discussed.

Genotypic and phenotypic heterogeneity of African Americans with primary iron overload

Primary iron overload may be relatively common in African Americans, but its cause is incompletely understood. Thus, we evaluated genotype and phenotype characteristics of unselected African American index patients with primary iron overload who reside in central Alabama. All had hepatic iron concentration > or =30 micromol/g dry wt or > or =2.0 g of iron mobilized by phlebotomy to achieve iron depletion. Genotype analyses were performed in African American control subjects from the same region. There were 23 patients (19 men, 4 women); mean age at diagnosis was 52 +/- 12 years (1 SD) (range 32-69 years). Nine (39.1%) reported that they consumed > or =45 g of ethanol daily; five had chronic hepatitis C. Eight had some form of hemoglobinopathy or thalassemia. Mean serum transferrin saturation was 56 +/- 28% (range 15-100%). The geometric mean serum ferritin at diagnosis was 1076 ng/mL [95% confidence interval 297-3473 ng/mL]. Increased stainable liver iron was observed in hepatocytes only in 4 patients, in macrophages only in 8 patients, and in hepatocytes and macrophages in 8 patients. The mean quantity of iron mobilized by phlebotomy (corrected for iron absorbed during treatment) was 5.3 +/- 2.0 g (range 4.0-8.4 g). Iron removed by phlebotomy was greater in patients with hemoglobinopathy or thalassemia than in those without these forms of anemia (6.6 +/- 1.3 g vs 3.9 +/- 1.6 g, respectively; P = 0.0144). Daily consumption of > or =45 g of ethanol or chronic hepatitis C was not associated with an increased or decreased amount of phlebotomy-mobilized iron, on the average. The percentage of index patients positive for HFE C282Y was greater than that of controls (P = 0.0058). The respective percentages of phenotype positivity for HFE H63D, D6S105(8), and HLA-A*03 were similar in patients and controls. HFE S65C, I105T, and G93R were not detected in index or control subjects. Two of 13 patients were heterozygous for the ferroportin allele nt 744 G-->T (Q248H), although the phenotype frequency of this allele was similar in patients and 39 controls. Synonymous ferroportin alleles were also detected in some patients. The ceruloplasmin mutation nt 1099C-->T (exon 6; Arg367Cys) was detected in 1 of 2 patients tested. Abnormal alleles of beta-2 microglobulin, Nramp2, TFR2, hepcidin, or IRP2 alleles were not detected in either of the 2 patients so tested. We conclude that primary iron overload in African Americans is not the result of the mutation of a single gene. HFE C282Y, ferroportin 744 G-->T, and common forms of heritable anemia appear to account for increased iron absorption or retention in some patients.

Phase II Trial of Alfimeprase, a Novel-Acting Fibrin Degradation Agent, for Occluded Central Venous Access Devices

PURPOSE Alfimeprase is a recombinantly produced, genetically modified variant of the metalloproteinase, fibrolase. Alfimeprase proteolytically cleaves fibrin, independent of plasminogen activation to plasmin, and directly dissolves thrombi. Based on the direct fibrin degradation effect of alfimeprase, rapid activity in patients with occluded central venous access devices (CVADs) was hypothesized. PATIENTS AND METHODS We performed a phase II, randomized, double-blind, active-control, multicenter, dose-ranging study to compare the safety and efficacy of one or two instillations of three intraluminal doses of alfimeprase (0.3, 1.0, and 3.0 mg) and alteplase 2.0 mg in re-establishing patency to occluded CVADs in 55 adult patients. RESULTS All three alfimeprase doses were more successful than alteplase during the first 15 and 30 minutes of treatment. The alfimeprase 3.0-mg dose resulted in 40%, 50%, and 60% patency restoration rates at 5, 15, and 30 minutes, respectively, compared with 0%, 0%, and 23% for alteplase. The difference at 15 minutes was highly significant (P = .0075). Alfimeprase 3.0 mg produced the highest patency rate at 120 minutes after the first (60%) and second (80%) doses. No major hemorrhagic or embolic events were reported. CONCLUSION A single 1- or 3-mg dose of alfimeprase has the potential to restore function to occluded CVADs rapidly and safely, and to facilitate on-time infusion of vital therapies.

Transfusion Iron Overload in Adults with Acute Leukemia: Manifestations and Therapy

BACKGROUND Hepatic dysfunction occurs commonly among persons successfully treated for acute leukemia, and iron overload is a possible cause of hepatic and other abnormalities in these patients. METHODS We identified 5 adults 40+/-13 (mean +/- S.D.) years of age who developed transfusion iron overload in association with successful chemotherapy of de novo acute leukemia. None had evidence of hemochromatosis, viral hepatitis, or other primary hepatic disorders. RESULTS The mean serum ferritin concentration of our patients was 1531+/-572 ng/mL. Other abnormalities associated with transfusion iron overload were increased stainable iron in bone marrow macrophages, elevated serum concentrations of hepatic enzymes, hyperpigmentation, hyperferremia, elevated iron saturation of serum transferrin, and increased stainable iron in Kupffer cells and hepatocytes. Rheumatologic, endocrinologic, or cardiac abnormalities attributable to iron overload were not observed. Therapeutic phlebotomy was initiated after chemotherapy; recovery of hemoglobin concentrations after phlebotomy permitted weekly treatment in each case. This yielded an average of 28+/-9 units per patient (range 15-35 units). Abnormalities associated with transfusion iron overload resolved after iron depletion therapy. The mean leukemia-free survival of our patients is 96+/-36 months (range 40-125 months). CONCLUSIONS Our data and those of others suggest that 15 to 20% of adults who are long-term survivors of acute leukemia develop iron overload, often with hepatic abnormalities. Iron overload is a relatively common sequela to successful management of acute leukemia in adults for which routine evaluation should be performed and for which therapeutic phlebotomy should be used as treatment.

Pica associated with iron deficiency or depletion: clinical and laboratory correlates in 262 non-pregnant adult outpatients

BackgroundThere are many descriptions of the association of pica with iron deficiency in adults, but there are few reports in which observations available at diagnosis of iron deficiency were analyzed using multivariable techniques to identify significant predictors of pica. We sought to identify clinical and laboratory correlates of pica in adults with iron deficiency or depletion using univariable and stepwise forward logistic regression analyses.MethodsWe reviewed charts of 262 non-pregnant adult outpatients (ages ≥18 y) who required treatment with intravenous iron dextran. We tabulated their sex, age, race/ethnicity, body mass index, symptoms and causes of iron deficiency or depletion, serum iron and complete blood count measures, and other conditions at diagnosis before intravenous iron dextran was administered. We excluded patients with serum creatinine >133 μmol/L or disorders that could affect erythrocyte or iron measures. Iron deficiency was defined as both SF <45 pmol/L and TS <10%. Iron depletion was defined as serum ferritin (SF) <112 pmol/L. We performed univariable comparisons and stepwise forward logistic regression analyses to identify significant correlates of pica.ResultsThere were 230 women (184 white, 46 black; ages 19-91 y) and 32 men (31 white, 1 black; ages 24-81 y). 118 patients (45.0%) reported pica; of these, 87.3% reported ice pica (pagophagia). In univariable analyses, patients with pica had lower mean age, black race/ethnicity, and higher prevalences of cardiopulmonary and epithelial manifestations. The prevalence of iron deficiency, with or without anemia, did not differ significantly between patients with and without pica reports. Mean hemoglobin and mean corpuscular volume (MCV) were lower and mean red blood cell distribution width (RDW) and platelet count were higher in patients with pica. Thrombocytosis occurred only in women and was more prevalent in those with pica (20.4% vs. 8.3%; p = 0.0050). Mean total iron-binding capacity was higher and mean serum ferritin was lower in patients with pica. Nineteen patients developed a second episode of iron deficiency or depletion; concordance of recurrent pica (or absence of pica) was 95%. Predictors of pica in logistic regression analyses were age and MCV (negative associations; p = 0.0250 and 0.0018, respectively) and RDW and platelet count (positive associations; p = 0.0009 and 0.02215, respectively); the odds ratios of these predictors were low.ConclusionsIn non-pregnant adult patients with iron deficiency or depletion, lower age is a significant predictor of pica. Patients with pica have lower MCV, higher RDW, and higher platelet counts than patients without pica.

HFE C282Y and H63D in adults with malignancies in a community medical oncology practice

BackgroundWe sought to compare frequencies of HFE C282Y and H63D alleles and associated odds ratios (OR) in 100 consecutive unrelated white adults with malignancy to those in 318 controls.MethodsData from patients with more than one malignancy were analyzed according to each primary malignancy. For the present study, OR ≥2.0 or ≤0.5 was defined to be increased or decreased, respectively.ResultsThere were 110 primary malignancies (52 hematologic neoplasms, 58 carcinomas) in the 100 adult patients. Allele frequencies were similar in patients and controls (C282Y: 0.0850 vs. 0.0896, respectively (OR = 0.9); H63D: 0.1400 vs. 0.1447, respectively (OR = 0.9)). Two patients had hemochromatosis and C282Y homozygosity. With C282Y, increased OR occurred in non-Hodgkin lymphoma, myeloproliferative disorders, and adenocarcinoma of prostate (2.0, 2.8, and 3.4, respectively); OR was decreased in myelodysplasia (0.4). With H63D, increased OR occurred in myeloproliferative disorders and adenocarcinomas of breast and prostate (2.4, 2.0, and 2.0, respectively); OR was decreased in non-Hodgkin lymphoma and B-chronic lymphocytic leukemia (0.5 and 0.4, respectively).ConclusionsIn 100 consecutive adults with malignancy evaluated in a community medical oncology practice, frequencies of HFE C282Y or H63D were similar to those in the general population. This suggests that C282Y or H63D is not associated with an overall increase in cancer risk. However, odds ratios computed in the present study suggest that increased (or decreased) risk for developing specific types of malignancy may be associated with the inheritance of HFE C282Y or H63D. Study of more patients with these specific types of malignancies is needed to determine if trends described herein would remain and yield significant differences.

Enhanced levels of both the membrane-bound and soluble forms of IgM Fc receptor (FcμR) in patients with chronic lymphocytic leukemia

The association of an IgM-Fc receptor (FcμR) with chronic lymphocytic leukemia (CLL) was suggested more than 30 years ago, but its authenticity has never been formally addressed. We examined the expression of the recently identified FcμR by B and T cells in CLL patients using receptor-specific monoclonal antibodies. CLL B cells (CD5(+)/CD19(+)) expressed much higher levels of FcμR on their cell surface than B cells from healthy donors. Such enhanced expression was more evident in immunoglobulin heavy chain variable region (IGHV)-mutated, CD38(-) or early Rai-stage CLL than in IGHV-unmutated, CD38(+), or advanced Rai-stage CLL. Intriguingly, surface FcμR levels also were significantly elevated in the non-CLL B cells (CD5(-)/CD19(+)) and T cells (CD5(+)/CD19(-)), especially in IGHV-mutated CLL. CLL patients also had high serum titers of FcμR compared with healthy donors, and serum FcμR levels correlated significantly with circulating lymphocyte numbers but not with the IGHV mutation status or Rai stage. The serum FcμR was resolved as an ∼ 40-kDa protein, distinct from the cell surface FcμR of ∼ 60 kDa, and it was produced by both CLL B and non-CLL B cells. Mass spectrometric analysis revealed that the serum FcμR is a soluble form of the receptor encoded by an alternatively spliced FcμR transcript. These findings indicate enhanced levels of both membrane-bound and soluble forms of FcμR in CLL patients.

The Long Elusive IgM Fc Receptor, FcμR

IgM exists as both a monomer on the surface of B cells and a pentamer secreted by plasma cells. Both pre-immune “natural” and antigen-induced “immune” IgM antibodies are important for protective immunity and for immune regulation of autoimmune processes by recognizing pathogens and self-antigens. Effector proteins interacting with the Fc portion of IgM, such as complement and complement receptors, have thus far been proposed but fail to fully account for the IgM-mediated protection and regulation. A major reason for this deficit in our understanding of IgM function seems to be lack of data on a long elusive Fc receptor for IgM (FcμR). We have recently identified a bona fide FcμR in both humans and mice. In this article we briefly review what we have learned so far about FcμR.