Hepatic iron concentration and total body iron stores in thalassemia major

BACKGROUND AND METHODS

We tested the usefulness of measuring the hepatic iron concentration to evaluate total body iron stores in patients who had been cured of thalassemia major by bone marrow transplantation and who were undergoing phlebotomy treatment to remove excess iron.

RESULTS

We began treatment with phlebotomy a mean (+/-SD) of 4.3+/-2.7 years after transplantation in 48 patients without hepatic cirrhosis. In the group of 25 patients with liver-biopsy samples that were at least 1.0 mg in dry weight, there was a significant correlation between the decrease in the hepatic iron concentration and total body iron stores (r=0.98, P<0.001). Assuming that the hepatic iron concentration is reduced to zero with complete removal of body iron stores during phlebotomy, the amount of total body iron stores (in milligrams per kilogram of body weight) is equivalent to 10.6 times the hepatic iron concentration (in milligrams per gram of liver, dry weight). With the use of this equation, we could reliably estimate total body iron stores as high as 250 mg per kilogram of body weight, with a standard error of less than 7.9.

CONCLUSIONS

The hepatic iron concentration is a reliable indicator of total body iron stores in patients with thalassemia major. In patients with transfusion-related iron overload, repeated determinations of the hepatic iron concentration can provide a quantitative means of measuring the long-term iron balance.

Treatment of iron overload in the "ex-thalassemic". Report from the phlebotomy program

After successful marrow transplantation (BMT) iron overload remains an important cause of morbidity in Thalassemia. After BMT, patients have normal erythropoiesis capable of producing a hyperplastic response to phlebotomy so that this procedure can be contemplated as a method of mobilizing iron from overloaded tissues. Forty-one patients (mean age 16 +/- 2.9 years) with prolonged follow-up (range 2-7 years) after BMT were submitted to a moderate intensity phlebotomy program (6 ml/kg blood withdrawal at 14-day intervals) to reduce iron overload. Values are expressed as mean +/- SD or as median with a range (25th-75th percentile). Serum ferritin decreased from 2,587 (2,129-4,817) to 280 (132-920) micrograms/l (p < 0.0001), total transferrin increased from 2.34 +/- 0.37 to 2.9 +/- 0.66 g/l (p = 0.0001), transferrin saturation decreased from 90% +/- 14% to 39% +/- 34% (p < 0.0001). Liver iron concentration evaluated on liver biopsy specimens decreased from 20.8 (15.5-28.1) to 3 (0.9-14.6) mg/g dry weight (p < 0.0001). Alanine amino-transaminase from 5.2 +/- 3.4 to 1.6 +/- 1.2 (p < 0.0001) times the upper level of normality. The histological grading for chronic hepatitis (Histology Activity Index) decreased from 4.2 +/- 2.4 to 2.3 +/- 1.8 (p < 0.0001). Phlebotomy is a safe, efficient, and widely applicable method to decrease iron overload in "ex-thalassemic."

Limitations of magnetic resonance imaging in measurement of hepatic iron

To evaluate the usefulness of magnetic resonance imaging for the quantitative determination of hepatic iron, we examined 43 patients with thalassemia major and assessed the influence of pathologic changes in the liver on the precision of estimates of the hepatic iron concentration. Tissue signal intensities were measured from magnetic resonance T1-weighted images derived from gradient-echo (GE) pulse sequences and the ratio of the signal intensity of liver to muscle calculated. By excluding patients (n = 9) having a signal intensity ratio (SIR) less than or equal to 0.2, a linear relationship with hepatic iron was found and subsequent analyses were limited to these 34 patients. In 27 patients with hepatic fibrosis, an overall correlation of -0.848 was found between hepatic iron and SIR. By contrast, in the seven patients with no fibrosis, the correlation coefficient (-0.993) was significantly greater (P < .0001). Despite the differences in correlation, the regression line between hepatic iron and SIR for the patients with no fibrosis did not differ significantly with respect to either slope or intercept from that of the patients with fibrosis. Thus, the presence of fibrosis did not seem to affect the pattern of the relationship between hepatic iron and the SIR, but rather to increase the variability of the relationship. Clinically, the presence of fibrosis makes estimates of hepatic iron derived from magnetic resonance imaging so variable as to be of little practical use in the management of transfusional iron overload.

Phlebotomy to reduce iron overload in patients cured of thalassemia by bone marrow transplantation. Italian Cooperative Group for Phlebotomy Treatment of Transplanted Thalassemia Patients

In thalassemia after successful bone marrow transplantation (BMT), iron overload remains an important cause of morbidity. After BMT, patients have normal erythropoiesis capable of producing a hyperplastic response to phlebotomy so that this procedure can be contemplated as a method of mobilizing iron from overloaded tissues. A phlebotomy program (6 mL/kg blood withdrawal at 14-day intervals) was proposed to 48 patients with prolonged follow-up (range, 2 to 7 years) after BMT. Seven patients were not submitted to the program (five because of refusal and two because of reversible side effects). The remaining 41 patients (mean age, 16 +/- 2.9 years) were treated for a mean period of 35 +/- 18 months. All were evaluated before and after 3 +/- 0.6 years of follow-up. Values are expressed as mean +/- standard deviation (SD) or as median with a range (25 to 75 percentile). Serum ferritin decreased from 2,587 (2,129 to 4,817) to 417 (210 to 982) microg/L (P < .0001), total transferrin increased from 2.34 +/- 0.37 to 2.7 +/- 0.58 g/L (P = .0001), transferrin saturation decreased from 90% +/- 14% to 50% +/- 29% (P < .0001). Liver iron concentration evaluated on liver biopsy specimens decreased from 20.8 (15.5 to 28.1) to 4.2 (1.6 to 14.6) mg/g dry weight (P < .0001). Aspartate transaminase decreased from 2.7 +/- 2 to 1.1 +/- 0.6 (P < .0001) and alanine transaminase from 5.2 +/- 3.4 to 1.7 +/- 1.2 (P < .0001) times the upper level of normality. The Knodell score for liver histological activity decreased from 6.9 +/- 3 to 4.9 +/- 2.8 (P < .0001). These data indicate that phlebotomy is safe, efficient, and widely applicable to ex-thalassemics after BMT.

Kaposi's sarcoma after allogeneic bone marrow transplantation

A case of Kaposi's sarcoma (KS) in an allogenic BMT recipient is reported. A 26-year-old man underwent allogeneic bone marrow transplantation for microdrepanocytosis. He received prolonged immunosuppressive therapy for mild chronic GVHD. Two years after BMT he developed KS localized to the skin. The KS improved rapidly and outcome was complete remission after cessation of immunosuppression.

Persistence of mixed chimerism in patients transplanted for the treatment of thalassemia

Molecular genetic techniques permit sensitive assessment of host hematopoiesis after marrow transplantation for thalassemia. Information on this persistence and the cell lines in which it occurs may permit therapeutic intervention in patients at high risk for rejection and/or relapse. The objective of this study, therefore, was to determine the evolution and cell line distribution of persistent mixed chimerism detected in 55 patients treated for beta thalassemia. Our findings indicated that rejection occurred in 20 patients, the host component disappeared in 20, and mixed chimerism without transfusion need persisted for 1 to 7 years in 15. In three patients with stable mixed chimerism for 4, 5, and 7 years, host hematopoiesis fluctuated between 25% and 75%. Despite this, donor pattern beta-globin chain synthesis maintained hemoglobin levels between 10 and 13.5 g/dL without transfusion. In these three patients, the polymerase chain reaction of the VNTR and the fluorescent in situ hybridization analysis revealed the coexistence of donor and host cells in the different peripheral blood cell subpopulations and precursors studied (CD2+, CD4+, CD8+, and CD19+ granulocytes; glycophorin-A+, erythroid burst-forming units, CD33+, granulocyte-macrophage colony-forming units). We found that rejection and disease recurrence occur in approximately one third of patients with early mixed chimerism. High levels of host type hematopoiesis can be present in patients not requiring transfusion.

Marrow transplantation for patients with thalassemia: results in class 3 patients

Thalassemia patients can be categorized as class 1 (minimal liver damage and iron overload), class 3 (extensive liver damage from iron overload), and class 2 (intermediate). These categories are prognostic for treatment outcome after marrow transplantation. Class 3 patients have more transplant-related mortality than other patients. This study examines transplantation outcome for class 3 patients. Records were reviewed of 215 patients in class 3 who received transplants in Pesaro from HLA-identical related donors between May 1, 1984 and May 1, 1994. The influence of pretransplant, peritransplant, and posttransplant variables on survival, relapse, and transplant-related mortality was examined by product-limit and proportional-hazards multivariate analysis. Age and conditioning regimen were influential on survival, and regimens with less than 200 mg/kg cyclosporine (CY) were associated with 5-year survival probabilities of .74 and .63 patients younger than 17 years and older patients, respectively. Transfusion history and regimen were influential on rejection with 5 year probabilities of .53 and .24 in patients who received less than or greater than 100 red blood cell transfusions before transplantation and regimens containing less than 200 mg/kg CY. Results of transplantation for patients with advanced thalassemia treatment have improved with the introduction of conditioning regimens with less CY. This has been associated with an increase in rejection (particularly in patients who have received < 100 red blood cell transfusions before transplant). Efforts at reducing the rejection rate by modifying the conditioning regimen should be concentrated on younger patients who have received a small number of transfusions. Patients with thalassemia who have HLA-identical family members should be transplanted before they are in class 3.

Needle liver biopsy in thalassaemia: analyses of diagnostic accuracy and safety in 1184 consecutive biopsies

We report the reliability and safety of percutaneous liver biopsy in the evaluation of hepatic iron loading and histology in patients with homozygous beta-thalassaemia prior to and in serial biopsies following allogeneic bone marrow transplantation for this disorder. 501 thalassaemic patients aged 11 +/- 4.5 years (range 1-32 years) underwent 1184 consecutive percutaneous liver biopsies without ultrasound guidance. Overall, 81% of biopsies were evaluable for histological examination and grading of iron. The adequacy of liver biopsy specimens increased with patient age: evaluable specimens were obtained in 73% of patients < 5 years of age and in 86% of samples in patients aged > 15 years. The degree of iron overload and fibrosis in each biopsy was reported separately by at least two pathologists who did not know the clinical status of each patient. In 103 biopsies, iron grade by light microscopy corresponded to an iron concentration varying between a mean of 32.46 +/- 14 mumol/g dry weight liver tissue for iron stores graded by light microscopy as absent to 417.6 +/- 150 mumol/g dry weight liver tissue for stores graded as severe. The fibrosis score of multiple samples of liver obtained at autopsy within 100 d of the percutaneous biopsy in 41 patients who died following BMT correlated perfectly with that of the first sample in > 60% biopsies; in most of the discordant cases fibrosis had been underestimated in the percutaneous biopsy. Liver biopsy demonstrated evidence of chronic hepatitis in 30% of patients with normal transaminase and in 57% of patients with transaminase within twice the normal range. Liver biopsy was complicated in six patients (0.5%) by haemoperitoneum, periocholecystic haematoma, kidney haematoma, or bile peritonitis; no complication was fatal. These data demonstrate that percutaneous liver biopsy provides reliable information regarding liver iron and histology in homozygous beta-thalassaemia with an extremely low risk of complications.

Allogeneic marrow transplantation in patients with chronic myeloid leukemia in chronic phase following preparation with busulfan and cyclophosphamide

Thirty-four patients with chronic myelogenous leukemia in chronic phase were treated with busulfan 16 mg/kg and cyclophosphamide 120 or 200 mg/kg before allogeneic bone marrow transplantation from an HLA-identical sibling. Cyclosporine, methotrexate and prednisone were used for graft-versus-host disease (GVHD) prophylaxis. The actuarial probabilities of survival and relapse-free survival at 82 months were 71%. With a maximum follow-up of 2471 days, none of the patient experienced hematologic or clinical relapse. In one patient reappearance of host cells was documented 180 days post-transplant which disappeared 277 days post-transplant and the patient is in complete hematological and cytogenetic remission 5 years after the transplant. The probability of transplant-related mortality was 29% while the probability of moderate to severe acute graft-versus-host disease was 38%. This study indicates that busulfan and cyclophosphamide are a good conditioning regimen for marrow transplantation in patients with chronic myeloid leukemia in chronic phase.