Sou-Ming Chuang

Biologic and prognostic significance of hepatocyte hepatitis B core antigen expressions in the natural course of chronic hepatitis B virus infection

To elucidate the biologic significance of hepatocyte hepatitis B core antigen (HBcAg) expression and its relation to the natural course of hepatitis B virus (HBV) infection, the patterns of HBcAg were correlated with HBV virus replication state and the disease activity in 598 needle liver biopsies performed on 569 hepatitis B surface antigen (HBsAg) carriers aged 1-81 years. A good correlation of liver HBcAg with serum HBeAg and HBV DNA status was demonstrated. HBcAg was present in the hepatocyte nuclei (nHBcAg) or cytoplasm (cHBcAg), or in both (mixed). Pure nHBcAg was seen mainly in children and young adults; 86% of the patients had non-aggressive disease, but rare cases of chronic active hepatitis (CAH) and HBeAg seroconversion were observed. In contrast, cHBcAg was predominantly associated with CAH (52%) and accompanied by a significantly higher HBeAg seroconversion rate (27%). The HBeAg-negative group, particularly the liver HBcAg-negative subgroup, had a lower frequency of CAH, but an increased incidence of non-aggressive disease as well as cirrhosis and/or hepatocellular carcinoma, indicating that HBeAg seroconversion to anti-HBe does not necessarily mean a favorable prognosis. The results suggest that expression of HBcAg correlates with the liver pathology and the three phases of chronic HBV infection: (1) the early immune tolerance phase is characterized by nHBcAg, mild disease and low HBeAg seroconversion rate; (2) the virus replication/elimination phase by cHBcAg or negative HBcAg, frequent CAH, and high HBeAg seroconversion rate; and (3) the inactive virus replication phase by negative HBcAg and a bipolar disease spectrum.

Clonal chromosomal abnormalities as direct evidence for clonality in nasal T/natural killer cell lymphomas

Nasal T/natural killer (NK) cell lymphoma is a distinct clinicopathologic entity which is more prevalent in Asia than in America and Europe. The clonal nature of the infiltrating lymphoid cells is difficult to demonstrate because of the lack of immunologic markers for clonality and the absence of clonal T‐cell receptor gene rearrangement in most cases. In this study, clonal chromosomal abnormalities were detected in the tumour cells from four patients with nasal T/NK cell lymphoma. This finding provided direct evidence for clonality of the disease. Moreover, nonrandom cytogenetic abnormalities, including isochromosome for the short arm (p) of chromosome 6, isochromosome for the long arm (q) of chromosome 1, partial deletion of 6q, and aberrations at 11q, were disclosed. Isochromosome 6p was the sole structural abnormality in one patient, which may be a pathognomonic change in nasal lymphoma.

Diverse virological, histopathological and prognostic implications of seroconversion from hepatitis B e antigen to anti-HBe in chronic hepatitis B virus infection

The evolutions of serum hepatitis B virus (HBV)-DNA, liver histology and intrahepatic expressions of HBV antigens were longitudinally investigated in 24 serum HBeAg+/HBV-DNA+ chronic hepatitis B patients who subsequently seroconverted to anti-HBe. After HBeAg conversion, serum HBV-DNA still persisted in 10 patients, and liver HBcAg in 7 of them. Of the 24 patients, 3 subgroups with diverse prognoses were identified. Ten patients progressed from chronic active hepatitis to cirrhosis, and in 7 of them HBV-DNA and/or HBcAg persisted. Eight patients with undetectable HBV-DNA and HBcAg recovered. In the remaining 6 patients, chronic liver diseases persisted; in 3 of them, HBV-DNA and in one HBcAg. These findings indicate that continued viral replication is present in a significant number of patients after HBeAg seroconversion in Taiwan, and is responsible for disease progression. In addition to HBcAg and HBV-DNA, the severity of underlying liver histology, when HBeAg seroconversion occurred, was critical for the outcome of the disease. Another remarkable finding was that clusters of ground-glass hepatocytes, well correlated with the marginal expression of HBsAg, were demonstrated in 14 of 16 biopsies with serum anti-HBe+/HBV-DNA-, but found in only 4 of 44 biopsies with positive serum HBV-DNA, indicating a strong association of the expressions of liver histology and hepatocyte HBsAg with the status of viral replication.

Characterization of the spectrum of postthymic T-cell malignancies in Taiwan. A clinicopathologic study of HTLV-1-positive and HTLV-1-negative cases.

Postthymic T‐cell malignancy shows marked geographic, clinicopathologic, and prognostic diversity. The frequency and spectrum of T‐cell malignancies in Taiwan were investigated. Fifty‐two patients (35 male and 17 female) with a median age of 49 years, were consecutively encountered between October 1983 and April 1987; these accounted for 39% of non‐Hodgkins lymphoma cases seen in our institutions. Ten patients (19.3%) had adult T‐cell leukemia/lymphoma (ATL) associated with human T‐cell leukemia virus (HTLV‐1). Patients with ATL had disease similar to that reported from southwestern Japan and the Caribbean. They had frequent skin lesions (60%), hypercalcemia (40%), and a rapid clinical course with a median survival of 1.3 years. The 35 HTLV‐1‐negative peripheral T‐cell lymphomas (PTL) were similar to PTL in western countries, manifesting frequent visceral, cutaneous, and vascular tropisms. Marrow involvement was documented at presentation in 39% and Stage III/IV disease in 80% of the PTL patients. The histology of PTL usually expressed prominent reactive features which is distinct from that in ATL. Several subcategories could be defined: Hodgkins‐like PTL in nine patients, T‐zone lymphoma in three, angioimmunoblastic lymphadenopathy‐like lymphoma in one, Lennerts lymphoma in three, and angioinvasive lymphoma in four. Two HTLV‐1‐negative PTL had neoplasiic cells with clover‐shaped nuclei and were designated as ATL‐like. Morphologic classification based on the modified Working Formulation showed prognostic correlation, with median survival of less than 6 months for large cell/immunoblastic PTL, compared with 5 years for patients with small/medium cell PTL. Both low‐ and high‐grade PTL seem to represent an incurable disease. Classical cutaneous T‐cell lymphoma (seven cases) is relatively unusual in Taiwan, compared with the frequency of PTL. Post‐thymic T‐cell malignancies in Taiwan include HTLV‐1‐positive and HTLV‐1‐negative diseases, both of which have a poor prognosis and resemble similar T‐cell malignancies in the East and West.

Chromosome studies on 30 Chinese patients with acute nonlymphocytic leukemia in Taiwan

Cytogenetic studies were performed on 32 consecutive Chinese patients with de novo acute nonlymphocytic leukemia (ANLL) in Taiwan. Of the 30 patients with adequate specimens, 20(66%) had clonal chromosome abnormalities. Structural rearrangements were detected in 18 of them. Seven (four were children) of the 16 patients with M2 ANLL had t(8;21). All six patients with acute promyelocytic leukemia (APL; M3 subtype) had t(15;17). Two patients with M4 type leukemia and abnormal bone marrow eosinophils had inv(16)(p13q22). Another M4 patient with a mild increase of morphologically normal eosinophils in the bone marrow had an abnormal chromosome #16, t(1;16)(q21;p13) in which 16q22 was not involved. One patient with M5 ANLL had t(9;11). Only two patients had a numerical change as the sole abnormality. None of the patients had loss or deletion of chromosome #5 or loss of chromosome #7, and only one had a deletion of 7q. This study revealed a high incidence of t(8;21), t(15;17), and a low incidence of -5/5q- or -7/7q- in Chinese patients with ANLL.

Cytogenetic study of acute lymphoblastic leukemia and its correlation with immunophenotype and genotype

Among 72 Chinese patients with acute lymphoblastic leukemia (ALL), 50 had clonal chromosomal abnormalities. Structural abnormalities were detected in 42 patients: these included t(9;22) in 9, t(1;19) in 6, t(4;11) in 5, del(11)(q23) in 4, and del(6q) in 4. Adults had a higher incidence of t(9;22) and t(1;19) but a lower incidence of t(4;11) and hyperdiploid greater than 50 karyotype than children. A significant difference was also noted in white blood cell (WBC) count among various karyotypic groups. Patients with chromosomal abnormalities t(9;22), t(1;19), t(4;11) and del(11) (q23) had a shorter complete remission duration as compared with patients free of these abnormalities. Immunophenotyping was performed on 69 patients. All patients with t(9;22), t(1;19), and t(4;11) had B-lineage ALL restricted to certain stages of maturation: groups III and IV, groups IV and V, and group II, respectively (according to the classification of Foon and Tood). Among patients with t(9;22), t(4;11), and del(11)(q23), which have been considered to be associated with acute mixed-lineage leukemia, one each, respectively, showed myeloid antigen expression on the leukemic blasts (My+ ALL). No cross-lineage rearrangements of immunoglobulin (Ig) or T-cell receptor (TCR) genes were detected in these karyotypic subgroups of patients who underwent gene analysis.

Chromosomal characteristics of Ph-positive chronic myelogenous leukemia in transformation: a study of 23 Chinese patients in Taiwan

Cytogenetic study was performed in the past 3 years on 23 Chinese patients with Philadelphia chromosome (Ph) positive chronic myelogenous leukemia (CML) in transformation; seven were in accelerated phase and 16 in acute blast crisis. Chromosomal abnormalities in addition to Ph were found in three (43%) of the patients at accelerated phase and 14 (88%) of the patients at blast crisis. The common nonrandom chromosomal aberrations were double Ph, trisomy 8, trisomy 19, and trisomy 21, which occurred in 47%, 41%, 35%, and 29%, respectively, of the total patients with extra chromosomal abnormalities. Isochromosome for the long arm of chromosome 17 was found in only one patient. In patients with blast crisis, the type of blast cell was characterized through morphologic, cytochemical, and immunocytochemical studies. Eleven cases were classified as myeloid and five as lymphoid transformation. Trisomy 8, 19, and 21 were detected only in patients with myeloid blast crisis. This study also revealed a high incidence of trisomy 21 and a low incidence of i(17q) in Chinese patients with transformation of CML.

Acute leukemic transformation of myelodysplastic syndrome—Immunophenotypic, genotypic, and cytogenetic studies

The clinical and biological characteristics of myelodysplastic syndrome (MDS) in acute leukemic transformation were studied in 23 patients. All had myeloid transformation according to FAB criteria, but coexpression of lymphoid-associated antigens was detected in five of the 20 patients who underwent an immunophenotypic study. Rearrangement of the immunoglobulin heavy chain gene was also observed in one of the five patients who coexpressed lymphoid markers and that of the T-cell receptor beta chain gene in another one. None had pure lymphoid transformation. Clonal chromosomal abnormalities were noted in 12 (63%) of the 19 patients who underwent cytogenetic study, most commonly - 7 (six patients or 32%). In the 18 patients who underwent serial analyses both at MDS diagnosis and at acute transformation, seven (39%) underwent karyotypic evolution. The most common new or additional aberrations were +8 and +21. N-ras gene mutation was detected in two of the nine patients at acute leukemic transformation. The median interval from diagnosis of MDS to onset of acute transformation was 10 months (1-36 months). Patients with a normal karyotype at diagnosis had a significantly longer chronic phase duration than those with chromosomal abnormalities (median of 20 months vs. 5 months). However, all had a short survival time after diagnosis of acute leukemia, whether chromosomal anomalies were present or not.

Cytogenetic characterization of Epstein-Barr virus-associated T-cell malignancies

Recently, Epstein-Barr virus (EBV) infection has been found not only to be associated with Burkitt lymphoma and nasopharyngeal carcinoma but also with some T-cell malignancies. Cytogenetic studies were performed on four Chinese patients with EBV-associated T-cell neoplasms: three peripheral T-cell lymphomas and one large granular lymphocyte leukemia with coexpression of T-cell antigen. Clonal chromosomal abnormalities were detected in all four patients. Rearrangements of chromosome 7 were observed in three patients: one at 7p22, one at 7q35 or 36, and the remaining one at both sites. The last patient also had a chromosomal abnormality involving 14q11. Trisomy of part of the 1q segment was detected in two patients. The results revealed that the chromosomal abnormalities in these patients were similar to those observed in other T-cell lymphomas. Further studies on more patients are necessary to find out whether there are specific chromosomal aberrations in EBV-associated T-cell neoplasms.

Comparison of clinical and biologic features between myeloid and lymphoid transformation of Philadelphia chromosome positive chronic myeloid leukemia

Analysis of clinical and biologic features of chronic myeloid leukemia (CML) in blast crisis (BC) was performed on 36 patients: 25 had myeloid and 11 had lymphoid transformation. The median duration from diagnosis to onset of BC was significantly shorter in patients with lymphoid BC (6 months) than in those with myeloid BC (41 months). Patients in lymphoid transformation showed better response to therapy and had a significantly longer median survival time after BC than patients with myeloid transformation (56% vs 0% and 10 months vs 4 months, respectively). The leukemic cells from all the patients with lymphoid BC showed B-cell immunophenotype, confirmed by the presence of immunoglobulin (Ig) heavy chain gene rearrangements in the five patients studied. Two of the eight patients with complete marker study expressed myeloid-associated antigens on the blasts. A high incidence of CD7 expression (7/17 or 41%) was found in patients with myeloid BC, but none of the patients who had DNA analysis showed rearrangement of T-cell receptor beta chain gene. Chromosomal abnormalities +8, +19, +21, and i(17q) were detected only in the patients with myeloid BC but not in those with lymphoid BC. Combined analysis of the patients in this series and those reported previously has revealed a statistically significant difference in the distribution of bcr breakpoints between myeloid and lymphoid BC: the bcr breakpoints in more than half of the patients with myeloid crisis were mapped to Zone 2 while those in patients with lymphoid crisis occurred most frequently in Zone 3.