Treatment of acute lymphoblastic leukaemia in countries with limited resources; lessons from use of a single protocol in India over a twenty year peroid

In the 1970s, survival rates after treatment for acute lymphoblastic leukaemia (ALL) in children and young adults (less than 25 years) in India were poor, even in specialised cancer centres. The introduction of a standard treatment protocol (MCP841) and improvements in supportive care in three major cancer centres in India led to an increase in the event-free survival rate (EFS) from less than 20% to 45-60% at 4 years. Results of treatment with protocol MCP841 between 1984 and 1990 have been published and are briefly reviewed here. In addition, previously unpublished data from 1048 patients treated between 1990 and 1997 are reported. Significant differences in both patient populations and treatment outcome were noted among the centres. In one centre, a sufficiently large number of patients were treated each year to perform an analysis of patient characteristics and outcome over time. Although steady improvement in outcome was observed, differences in the patient populations in the time periods examined were also noted. Remarkably, prognostic factors common to all three centres could not be defined. Total white blood cell count (WBC) was the only statistically significant risk factor identified in multivariate analyses in two of the centres. Age is strongly associated with outcome in Western series, but was not a risk factor for EFS in any of the centres. Comparison of patient characteristics with published series from Western nations indicated that patients from all three Indian centres had more extensive disease at presentation, as measured by WBC, lymphadenopathy and organomegaly. The proportions of ALLs with precursor T-cell immunophenotypes, particularly in Chennai, were also increased, even when differences in the age distribution were taken into consideration (in <18-year olds, the range was 21.1-42.7%), and in molecular analyses performed on leukaemic cells from over 250 patients less than 21-years-old with precursor B-cell ALL, a lower frequency of TEL-AML1-positive ALL cases than reported in Western series was observed. The worse outcome of treatment in Indian patients compared with recent Western series was probably due to the higher rate of toxic deaths in the Indian patients, and possibly also due to their more extensive disease - which is, at least partly, a consequence of delay in diagnosis. Differences in the spectrum of molecular subtypes may also have played a role. The higher toxic death rates observed are likely to have arisen from a combination of more extensive disease at diagnosis, co-morbidities (e.g., intercurrent infections), differences in the level of hygiene achievable in the average home, poor access to acute care, and more limited supportive care facilities in Indian hospitals. Toxic death was not associated with WBC at presentation, and hence would tend to obscure the importance of this, and, potentially, other risk factors, as prognostic indicators. Since the prevalence of individual risk factors varies in different populations and over time, their relative importance would also be expected to vary in different centres and in different time periods. This was, in fact, observed. These findings have important implications for the treatment of ALL in countries of low socioeconomic status; it cannot be assumed that risk factors defined in Western populations are equally appropriate for patient assignment to risk-adapted therapy groups in less affluent countries. They also demonstrate that heterogeneity in patient populations and resources can result in significant differences in outcome, even when the same treatment protocol is used. This is often overlooked when comparing published patient series.

TENS for the treatment of writer's cramp dystonia: A randomized, placebo-controlled study

Manipulation of afferent inputs may temporarily modulate dystonic spasms. Ten patients with writer's cramp were enrolled in a double-blind, randomized, crossover study in which the effects of transcutaneous electrical stimulation (TENS) and placebo treatment were compared. Patients were evaluated using four measures of dystonic impairment. The TENS group showed a significant improvement that persisted for 3 weeks in three of the four measures.

Report of an International Network of Cancer Treatment and Research workshop on non-Hodgkin's lymphoma in developing countries

The International Network of Cancer Treatment and Research (INCTR) recently organized a workshop on non-Hodgkin lymphomas (NHLs) in selected developing countries with the purpose of examining existing information relating to the pathology and management of these neoplasms, and identifying potential areas for research. This report provides a summary of the information presented and is focused primarily on the pathology of NHLs in children and adults. In most countries, the WHO classification of lymphomas was used and most participating centers included immunohistochemistry using a wide array of lymphoid antibodies as part of routine diagnosis. Some of the series had been reviewed by an external panel of experts. B-cell lymphomas accounted for 82-88% of all NHLs. The proportions of chronic lymphatic leukemia (4-6%), mantle cell lymphoma (MCL, 3-5%), and plasmacytoma (2-4%) were similar in the series presented. However, there was a significant variation in the proportion of follicular lymphoma (FL), which accounted for 15% and 11% in India and Kuwait, but less than 5% in Pakistan and Egypt. All of these frequencies are significantly lower than those reported in Western series. Diffuse large B-cell lymphoma accounted for about 35% of cases in India but for more 50% in other countries, but this difference was not accounted for by an increased incidence in a single lymphoma subtype in India, but rather an apparent paucity of several subtypes (such as mantle cell and marginal zone lymphomas (MZL)) in other series. There were relatively high frequencies of Burkitt lymphoma in Egypt (7%) and precursor T-cell lymphoblastic lymphoma in India (6-7%). Peripheral T-cell lymphomas (PTCLs) (not otherwise specified and angioimmunoblastic subtypes) accounted for 3-5% of NHLs, and extranodal lymphoma of T/NK cell type was rare (<1%). These differences in the relative proportions of NHL subtypes among developing countries and between developing countries and the rest of the world presumably arise from differences in environmental and genetic factors that influence lymphomagenesis and strongly suggest that more research in developing countries would provide valuable insights into the pathogenesis of lymphoid neoplasms.

Quantitative expression of TEL in childhood acute lymphoblastic leukemia

Loss of heterozygosity of chromosome 12p in human precursor B-cell ALL invariably results in loss of TEL coding sequences. Accompanied by a 12;21 translocation, such loss of heterozygosity ensures complete loss of the wild-type TEL. No inactivating mutations of the retained TEL allele have been reported in leukemias with hemizygous deletion. However, only minimal data reported the expression of the wild-type TEL in ALL. We now demonstrate that quantitative real-time RT-PCR from leukemic RNA samples could be indicative of compromised TEL expression in childhood ALL and therefore loss of TEL function.

Tau gene and Parkinson's disease: a case-control study and meta-analysis

OBJECTIVE

To investigate whether the tau H1 haplotype is a genetic risk factor in Parkinson's disease and to report a meta-analysis on all previously published data

METHODS

and results: In a sample of 580 patients with Parkinson's disease and 513 controls there was an increased risk of Parkinson's disease for both the tau H1 haplotype (p<or=0.0064; odds ratio (OR) 1.34 (95% confidence interval (CI), 1.04 to 1.72)) and the H1H1 genotype (p<or=0.0047; OR 1.42 (1.1 to 1.83)). Under a fixed effect model, the summary OR for this showed that individuals homozygous for the H1 allele were 1.57 times more likely to develop Parkinson's disease than individuals carrying the H2 allele (95% CI 1.33 to 1.85; p<0.00001). The population attributable risk for the tau variant, for the main comparison of H1H1 against H2 carriers, was 24.8% for all studies combined.

CONCLUSIONS

Homozygosity for the tau H1 is associated with an increased risk of Parkinson's disease. This adds to the growing body of evidence that common genetic variation contributes to the pathogenesis of this disorder.

Paucity of TEL-AML 1 translocation, by multiplex RT-PCR, in B-lineage acute lymphoblastic leukemia (ALL) in Indian patients

A total of 69 patients of B lineage ALL, 35 children (32 males, 3 females) and 34 young adults (27 males, 7 females) were studied by multiplex RT-PCR to determine the relative frequency of t(9;22), t(12;21), t(1;19), and t(4;11,). Translocation (9;22) was seen in 1/35 (2.8%) and t(1;19) in 2/35 (5.7%) children. None of the children showed t(12;21) and t(4;11) translocations. In young adults, t(9;22) and t(1;19) were seen in 5/34 (14.7%) and 2/34 (5.8%) patients, respectively. None of the latter showed t(12;21) or t(4;11) translocations. Thus, there appears to be a significant under representation of the fusion transcripts for TEL-AML, a good prognostic marker, in this study, unlike in the West, where it is seen in 35% of children with ALL. This, together with the generally increased leukemic burden seen in Indian patients, may explain in part, the poor treatment outcome reported.

Variable drug metabolism genes in Arab population

Cataloging interethnic differences in the distribution of genotypes of drug metabolic genes provides valuable information for profiling the pharmacogenetics of a population. We used PCR analysis to catalog the frequencies of alleles and genotypes for CYP1A1, NAT2, GSTs, MTHFR, MTR (MS) and NQO*1 in Arabs. The frequencies of alleles and/or genotypes for CYP1A1*2A, GSTT1 null, GSTT1 and GSTM1 double null, and GSTP1 A1578G in Arabs were significantly higher than those reported in Caucasians. However, the distribution of NAT2 acetylator phenotypes in both populations was similar. In contrast, the frequencies of MTHFR 677T allele and the combined (677+1298) genotypes for low activity were lower than those reported in Caucasians. Other alleles in Arabs, including CYP1A1 T3801C and GSTP1 A1578G were present in frequencies similar to Africans. The overall profile of variations in metabolism genes in Arabs is thus unique.

DJ-1 mutations in Parkinson's disease

Mutations in the DJ-1 gene have recently been shown to cause autosomal recessive Parkinson's disease. To estimate the prevalence of this mutation, an analysis was undertaken of 39 index cases of Parkinson's disease in whom a family history suggested autosomal recessive inheritance. No DJ-1 mutations were found in these patients, indicating that this gene is unlikely to be of numerical significance in clinical practice. The hypothesis was also tested that young onset Parkinson's disease patients in whom, despite extensive analysis, only a single heterozygous parkin mutation was found, might harbour a second mutation in the DJ-1 gene--that is, digenic inheritance. No patient was found with a single mutation in both DJ-1 and parkin genes, making this mode of inheritance unlikely. Finally it was confirmed that PARK6 and PARK7 (DJ-1), despite being phenotypically similar and mapping to the same small chromosomal region of 1p36, are caused by mutations in separate genes.

Concurrent methylation of multiple genes in childhood ALL: Correlation with phenotype and molecular subgroup

Multiple genes have been shown to be independently hypermethylated in lymphoid malignancies. We report here on the extent of concurrent methylation of E-cadherin, Dap-kinase, O(6)MGMT, p73, p16, p15 and p14 in 129 pediatric ALL cases. While most of these genes demonstrated methylation in a proportion of cases, O(6)MGMT, p16 and p14 were infrequently methylated (11, 7 and 3%, respectively). Methylation of at least one gene was found in the vast majority (83%) of cases. To determine the extent and concordance of methylation we calculated a methylation index (MI=number of methylated genes/number of studied genes) for each sample. The average MI was 0.28, corresponding to 2/7 methylated genes. MI was correlated with standard prognostic factors, including immunophenotype, age, sex, WBC and presence of specific translocations (TEL-AML1, BCR-ABL, E2A-PBX1 or MLL-AF4). We determined that children >/=10 years old and children presenting with high WBC (>/=50 x 10(9)/l) both associated with a higher MI (P<0.01 and <0.05, respectively). T-ALLs demonstrated a lower MI (median=0.17) than precursor B ALLs (median=0.28). Among the different molecular subgroups, MLL-ALLs had the highest MI (mean=0.35), while ALLs carrying the t(1;19) had the lowest MI (mean=0.07). The most common epigenetic lesion in childhood ALL was methylation of E-cadherin (72%) independent of the molecular subtype or other clinicopathological factors.

Association of primary central nervous system lymphomas with the Epstein-Barr virus

The incidence of primary central nervous system lymphoma (PCNSL), previously a rare tumor, has increased significantly over the past few decades, partly due to the AIDS epidemic but also in immunocompetent individuals. Studies from Western countries have shown a consistent association of tumors occurring in immunocompromised individuals with the Epstein-Barr virus (EBV) suggesting an important role for the virus in the pathogenesis of these tumors, but an infrequent association of the virus with PCNSL in the immunocompetent host has also been noted. We studied 11 patients with PCNSL who had no evidence of an immunocompromised state. All the tumors were aggressive B cell lymphomas. EBV association was studied using EBER in-situ hybridization. 10 out of the 11 tumors were negative for EBV, indicating that tumors in immunocompetent individuals in developing countries are also infrequently EBV associated and that a different pathogenetic mechanism is operative in the evolution of these tumors.

Septic cavernous sinus thrombosis secondary to sinusitis: are anticoagulants indicated? A review of the literature

This article reviews the contemporary literature for septic cavernous sinus thrombosis (CST) with a focus on anticoagulation. Modern emphasis is placed on suspecting and treating this condition early, which is aided by recognizing clinical features attributable to sepsis, orbital venous congestion, and involvement of cranial nerves within each cavernous sinus. Established treatments include high dose broad-spectrum parenteral antibiotics, and selective surgery for concurrent suppurations. The role of anticoagulation is contentious because its efficacy is undetermined and it may cause or exacerbate concurrent intracranial haemorrhage in patients with septic CST. Moreover, prospective trials of anticoagulation may never be performed due to the rarity of this condition. Nevertheless, retrospective reviews of published reports indicate that haemorrhage caused by anticoagulation is rare, and that early adjunctive anticoagulation is beneficial in these patients if commenced after excluding the haemorrhagic sequelae of CST radiologically.

Incidence, clinical characteristics and early treatment outcome in Indian patients of childhood acute lymphoblastic leukemia with ALL-1 gene rearrangement

In a series of 185 patients (median age 7 years) of acute lymphoblastic leukaemia (ALL) from India, the overall incidence of ALL-1 gene rearrangement using the Southern blot technique was 11.4% (21/185). The incidence amongst the infants (age < or = 1 year, 70%) was significantly higher when compared to patients > 1 - < or = 10 years (7.4%, P = 0.00001) as well as > 10 years old (9.3%, P = 0.0001). ALL-1 gene rearrangement was associated with significantly higher WBC count (P = 0.01) and CD10 negativity (P = 0.00000001). Complete remission (CR) and relapse rates in 98 patients evaluable for response to therapy on a uniform therapy protocol was independent of ALL-1 gene status.

Updated guidelines for the management of Parkinson's disease

New data on diagnosis, drug therapy, surgery and psychosocial concerns have emerged since the publication of the 1998 Guidelines for the Management of Parkinson's Disease. This article reviews new data and addresses issues left unanswered in the previous guidelines.

The peopling of New Guinea: evidence from class I human leukocyte antigen

This study utilizes newly developed direct DNA typing methods for human leukocyte antigens (HLA) to provide new information about the peopling of New Guinea. The complete polymorphism of eight Melanesian populations was examined. The groups included were highlanders, northern and southern highlands fringe populations, a Sepik population, northern and southern coastal New Guinea populations, and populations from the Bismarck Archipelago and New Caledonia. The study concluded that, based on HLA and other evidence. Melanesians are likely to have evolved largely from the same ancestral stock as Aboriginal Australians but to have since differentiated. Highlanders are likely to be descendants of earlier migrations who have been isolated for a long period of time. Northern highlands fringe and Sepik populations are likely to share a closer common ancestry but to have differentiated due to long term isolation and the relative proximity to the coast of the Sepik. Southern fringe populations are likely to have a different origin, possibly from the Gulf region, although there may be some admixture with neighboring groups. Coastal populations have a wider range of polymorphisms because of the genetic trail left by later population movement along the coast from Asia that did not reach Australia or remote Oceania. Other polymorphisms found in these populations may have been introduced by the movement of Austronesian-speaking and other more recent groups of people into the Pacific, because they share many polymorphisms with contemporary southeast Asians, Polynesians, and Micronesians that are not found in highlanders or Aboriginal Australians. There is evidence suggestive of later migration to Melanesia from Polynesia and Micronesia.

Expression of EBV encoded nuclear small non-polyadenylated RNA (EBER) molecules in 32 cases of childhood Burkitt's lymphoma from Israel

We have analyzed paraffin sections from 32 children with histologically confirmed Burkitt's Lymphoma (BL) for the presence of EBV using in situ hybridization to detect expression of the EBV-encoded early RNAs (EBERs). EBV was present in the tumors of 11 patients (34%). Sixty nine percent of the children presented with abdominal disease, 19% had bone marrow infiltration and only one child had jaw involvement. There was no statistically significant difference between EBV positive and EBV negative children with regard to age, gender, origin, primary site at presentation, or clinical stage of disease. However, there was a trend for younger age in the children with EBV positive BL with a median age of 4, compared to 7 years in children with EBV negative BL. None of the 7 children of Ashkenazi Jewish origin had EBER positive disease. There was no difference in the treatment outcome between the EBV positive patients (estimated survival at 24 months of 82%) and EBV negative children (estimated survival rate of 71% (p=0.58)). In conclusion, although this is only a small series it seems that childhood BL in Israel has the clinical characteristics of sporadic, non-African type with 34% EBV association and a low incidence of jaw tumors. Our data suggest that Ashkenazi Jewish children with BL are less likely to have EBV positive tumors than other ethnic groups. However, more patients will need to be studied in order to assess the validity of this observation.

Association of Burkitt's lymphoma with the Epstein-Barr virus in two developing countries

The clinical presentation of Burkitt's lymphoma (BL) and it's association with the Epstein-Barr virus (EBV) varies in different geographic areas, BL in developing countries being "intermediate" between the sporadic and endemic types, both in it's clinical presentation and it's association with EBV, which varies from 25-80%. In this study we have analysed the clinical features, EBV association, subtype and prevalence of the deleted variant of the Latent Membrane Protein-1 (LMP-1) of EBV in forty-two cases from two developing countries- India (n = 25) and Argentina (n = 17). In both countries the abdomen was the site most commonly involved while jaw involvement was rare. EBV was detected by in-situ hybridization using the EBER-1 RNA probe. 47% of cases from Argentina and 80% of cases from India were EBER positive. EBV typing using EBNA-3C primers showed a predominance of Type A in both countries (India-13/16 and Argentina-(7/8)). The 30bp deletion of the LMP-1 gene was detected in all evaluated cases from Argentina while the wild type of the gene was seen in all the evaluable Indian cases. Our study highlights the similarities and differences in the clinical presentation and EBV association of BL in two developing countries and also indicates that the subtype of EBV and prevalence of the LMP-1 deletion may reflect the predominant subtype in a particular population.

Pattern of immunoglobulin (Ig) and T-cell receptor (TCR) gene rearrangements in childhood acute lymphoblastic leukemia in India

In 120 cases of acute lymphoblastic leukemia (median age 8 years), IgH chain gene was rearranged in 99% B-Cell Precursor (BCP) ALLs and 13% T-ALLs. One or the other TCR locus was rearranged not only in all T-ALLs, but also in 87% of BCP-ALLs. TCR-beta rearrangement in BCP-ALL was associated with a higher mean age at presentation (8.7 vs. 6.2 years, P=0.008), lower mean platelet counts (61.2x10(9)/l vs. 103.7x10(9)/l, P=0.003) and a poorer DFS (% cummulative survival 0 vs. 88.9+/-10.5, P=0.004). TCR-gamma rearrangement in T-ALL was associated with a higher mean WBC count (186.3x10(9)/l vs. 63. 4x10(9)/l, P=0.002). Also, the pattern of rearrangement of these genes appeared to be different from the West; viz. TCR-beta rearrangement in a higher proportion of BCP-ALLs (58%, 95% confidence intervals 45-69%), invariable deletion of Cgamma1 and only monoallelic rearrangement for TCR-delta locus. This repertoire of gene rearrangement may have a bearing on the poor treatment outcome reported previously from our geographic region.

Discrepancies in Epstein-Barr virus association at presentation and relapse of classical Hodgkin's disease: impact on pathogenesis

BACKGROUND

Though Epstein-Barr virus (EBV) has been linked to classical Hodgkin's disease (cHD), only a proportion of cHD cases show EBV-association. While there has been evidence to suggest a crucial role for EBV in the early phase of cHD evolution, we are unclear whether continued presence of EBV is essential for the maintenance of the neoplasm. We have addressed this issue by investigating the EBV-association in paired samples of cHD obtained at presentation and relapse.

MATERIALS AND METHODS

We have analysed lymph node biopsy samples from 23 cases of cHD at presentation and relapse. In situ hybridization with EBER-1 probe and immunostaining with anti latent membrane protein-1 (LMP-1) antibody was performed on the paraffin sections. PCR for EBNA 3C gene was performed for EBV subtype analysis on the DNA extracted from paraffin sections.

RESULTS

EBV-association was documented in both the presentation and relapse samples of 14 cases. One case showed loss of EBV-association at relapse. PCR analysable DNA was obtained from both presentation and relapse samples in four of the EBV-associated cases. The EBNA 3C amplimer corresponded to type A strain of EBV in all the samples.

CONCLUSION

Loss of EBV-association between presentation and relapse seen in one case implies a hit and run mechanism in EBV-induced lymphomagenesis. Though EBV may be essential early in the evolution of cHD, it may not be required for maintenance of the neoplastic clone. Our study also brings out a speculation that a proportion of EBV-negative cHD could represent loss of EBV in the tumour prior to clinical presentation. Alternatively, an unidentified lymphotropic virus other than EBV might play a pathogenetic role in EBV-negative cHD.

Association of EBV strains, defined by multiple loci analyses, in non-Hodgkin lymphomas and reactive tissues from HIV positive and HIV negative patients

Epstein-Barr virus (EBV) associated with lymphoid neoplasms demonstrates preferential association with certain viral strains. Previous subtyping studies have however been confined to analysis of sequence variability within a single locus in EBV. Variations have now been reported for several latently expressed EBV genes, including, EBNAs-1, 2 and LMP-1. Variant EBNA-1 strains have been identified in Burkitt's lymphomas and clustering of subtypes for LMP and EBNA-2 have been associated with either malignancy and/or clinical disease. To investigate the linkage between the variability in these three loci in EBV associated with lymphoid malignancies, we subclassified EBV-associated lymphoproliferations (9 reactive and 24 malignant) from HIV-negative and HIV-positive patients by analysis of the EBNA-1, LMP1, and EBNA-2 genes. Our results demonstrate that (1) EBV identical to the prototype B95.8 strain (Type 1 EBNA-2, wild type EBNA-1 and LMP-1) is very rarely associated with tumors. (2) The EBNA-1 variant V-leucine, restricted to malignant lymphomas in immunocompetent patients, was readily identified in non-malignant lesions in HIV infected patients. (3) Variations of EBNA-1 occur independent of variations at other loci.