Role of chronic hepatitis in development of thalassaemic liver disease

Liver injury due to iron overload in thalassemia: histopathologic and ultrastructural studies

The livers of 30 cases of thalassemia (19/beta-thal/HbE, seven thal/HbH and four beta-thal major) were studied histopathologically and electron microscopically, in an effort to define the morphologic alterations due to iron overload. The results of light and electron microscopy were similar in most cases. Iron accumulation and fibrosis were the common features found in these patients, except that thal/HbH exhibited lesser hepatic damage. The degrees of iron deposition and fibrosis were found to be higher in splenectomized and cirrhotic than non-splenectomized and non-cirrhotic patients. The subcellular changes were swollen mitochondria, with the presence of an electron dense matrix and ruptured mitochondrial membrane. Proliferation of smooth endoplasmic reticulum (ER) and dilated rough ER was observed. Increases in lysosomal hemosiderin in hepatocytes and in Kupffer cells were demonstrated. The possible ways by which the iron compounds or free radicals mediated membrane damage are mentioned. The pattern of liver cell damage is similar to that of viral hepatitis.

Use of the ferritin/alanine aspartate transaminase ratio as an iron overload marker independent of liver cell damage

To define an iron overload index independent of liver cell damage, the mean annual levels of alanine aspartate transaminase (ALAT) and serum ferritin and their ratios were determined. Ferritin/ALAT ratio values were compared between two groups of patients with acute or chronic hepatitis without iron overload, and one group of thalassaemic patients with iron overload. The two groups without iron overload exhibited ferritin/ALAT ratio values of 2 and 1.2 respectively; a ratio value higher than 10 was always observed in those patients with iron overload. The ferritin/ALAT ratio is correlated with the degree of iron overload. This ratio increases in regularly-transfused patients without chelation treatment. It generally remains stable or decreases after initiation of iron chelation therapy. The ferritin/ALAT ratio thus appears useful in the follow-up of patients subjected to a long-term transfusional treatment particularly when acute or chronic liver cell damage may interfere with iron overload by increasing serum ferritin values.

Iron state and hepatic disease in patients with thalassaemia major, treated with long term subcutaneous desferrioxamine

Liver biopsies were performed on 51 regularly transfused patients with beta thalassaemia, age range 5-36 (mean 18.6) years, who had received regular subcutaneous desferrioxamine (DFX) treatment for periods between one and eight years (40 for eight years). The biopsy specimens were examined by light microscopy and immunofluorescence for hepatitis B virus surface and core antigens (HBsAg and HBcAg), and the iron content was determined chemically. The results were compared with serum ferritin concentration and aspartate transaminase (AST) activity and with hepatitis B virus serology. Biopsy specimens, in which chemical liver iron had been determined in 12, were also available from 17 patients. Mean serum ferritin (+/- SD) had fallen from 5885 (3245) micrograms/l to 1638 (976) micrograms/l in 36 patients after eight years' chelation, while mean (+/- SD) liver iron concentration had fallen from 2945 (900) micrograms/100 mg dry weight to 857 (435) micrograms/100 mg dry weight in 12 of them. All biopsy specimens examined were negative for HBs and HBc antigens. The presence of histological features of hepatitis was associated with increased liver iron content, increased fibrosis, and with progression of fibrosis between the two biopsies. Procollagen III peptide was assayed in 28 patients but did not correlate with the degree of hepatitis, fibrosis, or with chemical liver iron content. We conclude that with regular subcutaneous DFX, mean concentrations of serum ferritin and liver iron are maintained in these patients at about five and 10 times the normal value, respectively, and that progression of liver damage is more likely to be due to viral hepatitis, presumably related to the parenterally transmitted non-A, non-B agents than to iron overload.

Hepatic fibrosis and cirrhosis in tropical countries (including portal hypertension)

The spectrum of diseases seen in patients from certain 'tropical areas' requires that a physician be aware of some of the syndromes discussed here. A high index of suspicion for less usual causes of cirrhosis is imperative when evaluating such patients presenting with hepatocellular disease. The differential must be expanded and the work-up complete. Liver biopsy should be performed as early in the course of disease as is feasible and will often provide valuable diagnostic information. It will not only facilitate treatment but allow for needed clinical trials and may help to increase our understanding of the various disease processes.

Altered T cell subsets and function in polytransfused beta-thalassemia patients: correlation with sex and age at first transfusion

Monoclonal antibodies (OKT series) have been used to investigate possible modifications of T lymphocytes and T lymphocyte subsets in 65 multiply transfused beta-thalassemia patients. No significant difference was observed in percentage and absolute number of OKT3-, OKT4-, and OKT8-positive cells when compared to controls. A subgroup of patients (10 patients, 15.3%), however, could be selected who showed a reversal of OKT4/OKT8 ratio. These patients did not differ from the others as to age, number of transfusions, frequency of splenectomy, ferritin levels, hepatitis B markers, chronic liver disease incidence, and numbers of B lymphocytes and natural killer cells. The features distinguishing this group from the remaining patients were: decreased mitogen responsiveness; early age when first transfused; high incidence of males (90%). Immunological investigation was done in 2 occasions, 1 year apart, but no significant modification was observed in these patients. These findings suggest that in beta-thalassemia patients transfusion therapy started very early in life may be responsible for persistent immunological modifications. The susceptibility to such modifications might be greater in males.

Hepatitis B or non-A, non-B virus infection in multitransfused thalassaemic patients

We undertook a four year study of 128 thalassaemic patients who had undergone several transfusions, to determine the incidence of hepatitis B virus markers and the activities of transaminases in their sera each month. The results showed that the possibility of these patients contracting hepatitis B virus infection is still high, although on only one occasion was a transient antigenaemia found, indicating low viral replication. Furthermore, the probability of contact with hepatitis B virus increases with the number of transfusions and, therefore, with age. About 25% of these patients were positive for hepatitis B markers and 80% for other hepatitis markers including the case of cytomegalovirus hepatitis.

Cirrhosis associated with multiple transfusions in thalassaemia

The study of surgical liver biopsy specimens obtained during splenectomy in 86 children with thalassaemia indicated that such patients may develop liver disease that evolves into cirrhosis. Histological characteristics suggest that it is post-necrotic cirrhosis. Onset of cirrhosis in some patients may occur as early as 7-8 years old, and at age about 15-16 years most children with thalassaemia show features of cirrhosis. In addition to fibrosis, hepatitis, or even aggressive hepatitis may develop as has also been observed in patients without thalassaemia who have undergone multiple transfusions. This study presents the current probable evolution of liver disease in patients with thalassaemia and may thus serve as a reference from which to evaluate any future progress in the treatment and care of patients with Cooley's disease.

Internal distribution of excess iron and sources of serum ferritin in patients with thalassemia

Liver and spleen iron concentrations, serum ferritin level and binding of S-ferritin to concanavalin A (Con A) were measured in 12 patients with thalassaemia major or intermedia at the time of splenectomy. All these subjects had increased liver iron concentration, most of them had hepatic fibrosis but none of them had histological evidence of chronic hepatitis. No patient had ascorbic acid deficiency. Serum ferritin concentration was increased in all cases, ranging from 266 to 5504 micrograms/l. In all but 2 subjects most of the protein did not bind to Con A, thus behaving as tissue ferritin. There were highly significant correlations between serum ferritin concentration, amount of blood transfused and liver iron concentration. On the average, iron concentration in the liver was about 3 times that in the spleen. The findings obtained suggest that in patients with thalassaemia major or intermedia most of the iron is deposited in parenchymal tissues and most of the S-ferritin derives by leakage from the cytosol of iron-loaded parenchymal cells. S-ferritin is a valid index of liver iron overload in thalassaemic patients without complications such as viral hepatitis and/or ascorbic acid deficiency.

Chronic viral hepatitis in thalassemic liver disease. A long-term study in patients with acute hepatitis with nontransfusion-dependent thalassemia minor

To evaluate the effective role of hepatitis viruses in thalassemic (Th) liver disease, we carried out a long-term study in 42 subjects with nontransfusion-dependent Th minor hospitalized for an episode of acute viral hepatitis. 10 patients had serologic evidence of hepatitis A, 23 of hepatitis B and 9 of hepatitis non-A, non-B. In the follow-up chronic hepatitis was detected histologically in 5/23 patients with hepatitis B and 5/9 with hepatitis non-A, non-B. All hepatitis A patients recovered completely. The prevalence in 7 out of 10 patients with chronic hepatitis of piecemeal necrosis and of inflammatory changes over hepatic siderosis and fibrosis evidenced a determinant role of chronic viral infection in the development of liver damage in these patients. Thus, heterozygous nontransfusion-dependent Th patients seem to have a high risk of developing a chronic inflammatory liver disease especially after an episode of non-A, non-B hepatitis. Therefore, in our geographical area, chronic hepatitis of viral origin should be taken into account, among other pathogenetic factors, in many cases of cryptogenic thalassemic liver disease.

Elevated IgG and decreased complement component C3 and factor B in B-thalassaemia major

Serum immunoglobulins, complements C3 and C4 and factor B were assayed in the sera of children with B-thalassaemia major, siblings and matched controls in an attempt to resolve the controversy surrounding the conflicting results reported in the literature. Significantly elevated IgG and decreased C3 and factor B levels were observed in thalassaemic patients who also had a high incidence of HBS hepatitis and other infections. The controversial results probably reflect differences in the incidence of infection, and the presence of circulating immune complexes due to blood transfusions, in the various communities. The alterations in immunoglobulin and complement levels represent a secondary rather than a primary immune disorder.

Chronic liver disease in transfusion-dependent thalassaemia: hepatitis B virus marker studies

The systematic screening of 253 children with transfusion-dependent homozygous beta-thalassaemia revealed a high incidence of hepatitis B virus markers. The highest frequencies of hepatitis B surface antigen (HBsAg) and antibody to hepatitis B core antigen (anti-HBc) were found in the group of patients with the smallest number of transfusions, while the highest frequency of antibody to hepatitis B surface antigen (anti-HBs) was detected in the patients who had had the largest number of transfusions. Follow-up of these patients showed (a) a high incidence of acute hepatitis B, which was mainly subclinical; (b) normal hepatitis B surface antigen clearance and normal antibody to hepatitis B surface development; and (c) a high frequency of increased transaminase values for over six months. In all the subjects with persistently high transaminase, histological examination revealed chronic persistent hepatitis or chronic active hepatitis. Apart from two cases of chronic active hepatitis with no B virus markers, and two cases of chronic persistent hepatitis with HBsAg and anti-HBc in the serum, all these subjects were anti-HBs positive but HGsAg and anti-HBc negative.

Sequential study of liver biopsy in thalassaemia

Liver biopsies were performed in 47 thalassaemic children. 33 of them had laboratory findings that suggested chronic hepatitis; the other 14 patients, without such signs, underwent liver biopsies during splenectomy. Nine patients showed a more or less pronounced fibrosis, 26 showed chronic persistent hepatitis, and 12 had histological evidence of chronic aggressive hepatitis. The last 12 patients who had been treated with corticosteroids, and 9 other patients who showed a worsening of their liver function tests, underwent sequential biopsy. We suggest that chronic liver disease in thalassaemic children can produce inflammatory infiltration even without biochemical or clinical sign of chronic hepatitis, that it can progress towards cirrhosis even in patients with chronic persistent hepatitis, and that there appears to be no benefit in giving corticosteroids.

Pathophysiology of thalassemia

The clinical manifestations in homozygous thalassemia may be attributed to the defect in hemoglobin synthesis (Figure 16). It is best typified by beta thalassemia, where excess alpha chains accumulate to form intracytoplasmic erythrocytic inclusions. This leads to anemia, bone marrow hyperplasia, osteoporosis, hemosiderosis, and organ failure.

Serum ferritin, liver iron stores, and liver histology in children with thalassaemia

Serum ferritin, liver iron stores, and liver histology were studied in 38 children with thalassaemia major who were being treated by regular blood transfusions. There was no correlation between serum ferritin levels and either the number of transfusions or the amount of iron deposited in the liver. However, for a given level of iron stores, ferritin levels were higher in patients with chronic hepatitis (including chronic aggressive and chronic persistent forms) than in those with hepatic siderosis only. We conclude that serum ferritin reflects tissue iron deposits in regularly transfused thalassaemic patients, only in the absence of hepatitis.

Lymphocyte changes in beta-thalassaemia major

Lymphocyte subpopulations were studied in 20 hypertransfused patients with beta-thalassaemia major, some of whom had been splenectomised. B-lymphocytes were normal but T-lymphocytes were decreased in all patients. The T-cell count was lower in the splenectomised patients than in the nonsplenectomised ones. In the former, the active rosette-forming lymphocytes were also diminished, but the difference was not significant. In all patients the percentage of null cells was greater and the activity of K-cells increased compared with controls.

Occurrence of circulating immune complexes in beta-thalassaemia major

The presence of circulating soluble immune complexes and the level of complement were investigated in sera from 21 patients with beta-thalassaemia major, including both splenectomised and nonsplenectomised patients. A high level of immune complexes was found in half of these cases. Reduced complement levels were seen less frequently. There was no correlation between the presence of circulating immune complexes, decreased complement levels, and thpresence or absence of the spleen. The level of immune complexes increased with the age ofthe individual, i.e. with the duration of the disease.