Acute Myeloid Leukemia Following Treatment with Cladribine for Hairy Cell Leukemia: A Case Report and Review of the Literature

The overall survival of patients with hairy cell leukemia (HCL) has significantly increased in recent years because of the development of effective treatments such as interferon alpha and purine analogs. Several reports have described an increased risk of secondary cancers, particularly solid tumors, in patients with HCL. We describe a case of a patient with HCL, who had prolonged pancytopenia after a single course of cladribine. Fifteen months after the diagnosis of HCL the patient developed acute myeloid leukemia (AML) and died shortly afterwards. Review of the literature shows few reports of acute leukemia in HCL patients. All of the 11 reported cases of leukemia in patients with HCL have been in patients who have been treated with either interferon alpha or purine analogs, and developed several years (mean 4.3 years; range 1.6-6.4 years) after the diagnosis of HCL. Our case is unusual in that the patient developed AML shortly (1.2 years) after the diagnosis and treatment of HCL. Further studies are needed to clarify whether leukemias seen in patients following the treatment of their HCL are incidental findings or related to HCL and its treatments.

Role of fibrinolytic markers in acute stroke

INTRODUCTION

The fibrinolytic system plays an important role in normal haemostasis and endothelial function. This study was conducted to compare three fibrinolytic markers, i.e. plasminogen, tissue-plasminogen activator (t-PA) and plasminogen activator inhibitor type-1 (PAI-1) between acute stroke and stable non-stroke patients and to investigate the clinical significance of these markers.

METHODS

A prospective study was done for a one-year period upon obtaining ethical approval from the local institution. 106 non-stroke individuals from general outpatient clinics (control group) and 51 acute stroke patients were selected. All subjects were tested for t-PA and PAI-1 levels using the enzyme immunoassay technique (Biopool TintElize) and for plasminogen level by colorimetric assay (HemosIL). They were followed up over a period of three months for survival and neurological recovery.

RESULTS

Only the mean t-PA level was significantly higher in acute stroke patients compared to the control group, including after adjusting for confounders (using ANCOVA). There was no statistical association between the three fibrinolytic markers and the age, gender, stroke subtypes, number of risk factors, functional impairment, survival and neurological recovery. We observed that all the eight patients who died within one month of stroke onset had high levels of t-PA. An association between high t-PA antigen and acute stroke was found during a cerebrovascular event with a 4.6-fold odds ratio compared to non-stroke controls.

CONCLUSION

High t-PA antigen in acute stroke patients probably indicates a poor prognosis. Its value as a marker for monitoring and prognostication needs to be evaluated as a routine clinical practice.

Pre-referral rectal artesunate to prevent death and disability in severe malaria: a placebo-controlled trial

BACKGROUND

Most malaria deaths occur in rural areas. Rapid progression from illness to death can be interrupted by prompt, effective medication. Antimalarial treatment cannot rescue terminally ill patients but could be effective if given earlier. If patients who cannot be treated orally are several hours from facilities for injections, rectal artesunate can be given before referral and acts rapidly on parasites. We investigated whether this intervention reduced mortality and permanent disability.

METHODS

In Bangladesh, Ghana, and Tanzania, patients with suspected severe malaria who could not be treated orally were allocated randomly to a single artesunate (n=8954) or placebo (n=8872) suppository by taking the next numbered box, then referred to clinics at which injections could be given. Those with antimalarial injections or negative blood smears before randomisation were excluded, leaving 12 068 patients (6072 artesunate, 5996 placebo) for analysis. Primary endpoints were mortality, assessed 7-30 days later, and permanent disability, reassessed periodically. All investigators were masked to group assignment. Analysis was by intention to treat. This study is registered in all three countries, numbers ISRCTN83979018, 46343627, and 76987662.

RESULTS

Mortality was 154 of 6072 artesunate versus 177 of 5996 placebo (2.5%vs 3.0%, p=0.1). Two versus 13 (0.03%vs 0.22%, p=0.0020) were permanently disabled; total dead or disabled: 156 versus 190 (2.6%vs 3.2%, p=0.0484). There was no reduction in early mortality (56 vs 51 deaths within 6 h; median 2 h). In patients reaching clinic within 6 h (median 3 h), pre-referral artesunate had no significant effect on death after 6 h or permanent disability (71/4450 [1.6%] vs 82/4426 [1.9%], risk ratio 0.86 [95% CI 0.63-1.18], p=0.35). In patients still not in clinic after more than 6 h, however, half were still not there after more than 15 h, and pre-referral rectal artesunate significantly reduced death or permanent disability (29/1566 [1.9%] vs 57/1519 [3.8%], risk ratio 0.49 [95% CI 0.32-0.77], p=0.0013).

INTERPRETATION

If patients with severe malaria cannot be treated orally and access to injections will take several hours, a single inexpensive artesunate suppository at the time of referral substantially reduces the risk of death or permanent disability.

FUNDING

UNICEF/UNDP/World Bank Special Programme for Research and Training in Tropical Diseases (WHO/TDR); WHO Global Malaria Programme (WHO/GMP); Sall Family Foundation; the European Union (QLRT-2000-01430); the UK Medical Research Council; USAID; Irish Aid; the Karolinska Institute; and the University of Oxford Clinical Trial Service Unit (CTSU).

Isolation and characterization of microsatellite loci in the Malaysian giant freshwater prawn, Macrobrachium rosenbergii

Eight single locus microsatellite markers were developed to characterize the Malaysian giant freshwater prawn, Macrobrachium rosenbergii. These microsatellites were isolated from an enriched genomic library contained by using a 5'-anchored polymerase chain reaction technique. Primers were designed to flank the repeat sequences and subsequently used to characterize 30 unrelated individuals of the giant freshwater prawn. The polymerase chain reaction amplification products of these eight microsatellite loci were polymorphic with the number of alleles ranging from two to 10 alleles per locus while the levels of heterozygosity ranged from 0.6333 to 0.8667.

Tropical pulmonary eosinophilia in a patient undergoing open heart surgery

A 35 years old male living in Jamalpur district of Bangladesh working as a shopkeeper presented with dyspnea, fatigue, occasional fever and cough for two years. He did not give any history of hemoptysis or weight loss. He was smoker and non-alcoholic. He had a soft systolic murmur over pulmonary area and wide fixed splitting of the second heart sound. An Atrial septal defect (ASD) was detected by echocardiography. The patient had high circulating eosinophil count and Complement Fixation Test for filarial antibody revealed positive result. Moreover the patient's response to drug Diethylcarbamazime indicated suspected tropical pulmonary eosinophilia with Atrial Septal Defect.

A phase 1 study of MORAb-009, a monoclonal antibody against mesothelin in pancreatic cancer, mesothelioma and ovarian adenocarcinoma

14041

Background: MORAb-009 is a monoclonal antibody that targets mesothelin, a cell surface adhesive protein overexpressed in pancreatic, ovarian, non-small cell lung carcinomas and mesothelioma and has minimal expression in normal tissue. The target is over-expressed by tumor cells. It was identified as one of the most prominent, differentially expressed cell surface antigens on pancreatic adenocarcinoma using SAGE of primary tumors vs. normal pancreatic tissue. In vitro studies show MORAb-009 to be effective in mediating cell killing by ADCC and inhibiting cell adhesion.. In xenograft models, MORAb-009 has single agent anti-tumor activity enhanced by the addition of chemotherapy. Toxicology studies show no toxicity in non-human primates and no significant binding to non-tumor tissues. Methods: Sequential cohorts of 3 patients received MORAb-009 intravenously on days 1, 8, 15 and 22 at doses of 12.5, 25, 50 and 100 mg/m2. Major inclusion criteria are the presence of a mesothelin-positive tumor with progression on primary therapy, acceptable organ function, ECOG PS 0–2, and measurable disease by CT. Safety pharmacology studies include chemistry, hematology, urinalysis and EKG. Tumors were re-imaged at day 35. Results: 11 patients have received MORAb-009 at doses up to 100 mg/m2. 6 patients had mesothelioma, 3 had pancreatic cancer and 2 had mesothelin-positive ovarian cancer. 4 patients exhibited grade 1 (3) or 2 (1) infusion reactions; no dose limiting toxicity was observed. A subject in the 50 mg/m2 cohort with pancreatic cancer who progressed on gemcitabine showed stable disease by CT and a drop in CA 19/9. Based on the response, this patient continues on extended MORAb-009 therapy. Enrollment to the final cohort of 200mgs/m2 is ongoing, as are pharmacokinetic and anti-MORAb-009 antibody analysis. Conclusion: MORAb-009, a monoclonal antibody against mesothelin is safe and well tolerated at doses up to 100 mg/m2. One subject with previously progressive pancreatic cancer had disease stabilization. In light of the positive preclinical data and safe clinical profile, this study supports further evaluation of the efficacy of MORAb-009 in mesothelin-positive tumors.

No significant financial relationships to disclose.

Molecular analysis of the Epstein-Barr virus LMP1 in Hodgkin lymphoma from Argentina and Brazil: Identification of a distinct LMP1 deleted variant

21099

Background: Epstein Barr virus (EBV), a human oncogenic virus, has two types, EBV1 and 2, and several polymorphic markers allow individual variants to be distinguished. Variations in EBV latent membrane protein 1 (LMP1) gene could define a more oncogenic strain or reflect geographic EBV origin. By sequence analysis of C-ter, N-ter and promoter (prom) regions, 4 distinct EBV groups (A to D) have been defined. Aim: To analyze LMP1 molecular variability of two different groups of Hodgkin`s lymphoma (HL) from the same geographic area. Methods: EBV association by EBERs in situ hibridization and LMP1 immunohistochemistry was analyzed in 27 HL from Argentina (Arg) and 36 HL from Brazil (Br). EBV type was assessed by EBNA PCR. C-ter LMP1 PCR was done in all cases. Sequencing of C-ter, N-ter and prom regions was done in 16 patients. Results: 21/27 (78%) Arg HL and 31/36 (86%) Br HL were EBV1, while 6/27 (22%) and 4/36 (11%) were EBV2, respectively (p= 0.29). Coinfection was observed in 1 (3%) Br HL. LMP1 deleted (del) variant was observed in 20/27 (74%) Arg HL and 20/36 (55%) Br HL (p= 0.18), as well as in non-neoplastic controls, 4/11 and 3/10 (36 and 30%) from Arg and Br respectively. Most LMP1 del displayed high number (5–7) of 33bp repeats (86% LMP1 del Br HL and 77% LMP1 del Arg HL) compared with LMP1 wt that exhibited low number (3–4) 33bp repeats (68% LMP1 wt Br HL and 100% LMP1 wt Arg HL). Analysis of LMP1 sequences showed that: LMP1 wt C-ter regions had unmutated N-ter and prom as B95.8, A and B groups (31%), except for a case showing new mutations. LMP1 del C-ter regions showed molecular identity with C group, but they showed new, undescribed mutations in prom and N-ter (63%). Conclusions: We found high frequency of LMP1 del variants in HL from Argentina and Brazil, which was associated with high number of 33bp repeats in C-ter region. This suggests a role for this variant in lymphomagenesis. A new molecular variant with characteristic promoter and N-ter mutations was identified in LMP1 del cases, which could be proposed as a regional South American variant.

No significant financial relationships to disclose.

Phase I study of SS1P, a recombinant anti-mesothelin immunotoxin for targeted therapy of mesothelin expressing mesotheliomas, ovarian and pancreatic cancer

3553

Background: Mesothelin, a cell surface glycoprotein, is an attractive candidate for targeted cancer therapy given its limited expression on normal mesothelial cells and high expression in several human cancers including mesothelioma, ovarian and pancreatic cancer. We conducted a phase I study to determine the maximum tolerated dose (MTD), toxicity and pharmacokinetics of SS1P, a recombinant anti-mesothelin immunotoxin. Methods: SS1P given as a 30 minute intravenous infusion was administered to 34 patients (pts) with advanced mesothelioma (n = 19), ovarian (n = 13) and pancreatic (n = 2) cancer. SS1P was administered every other day (QOD) for 6 doses to 17 pts and then QOD for 3 doses to 17 other pts. Results: The initial cohort of 17 pts received SS1P QOD x 6 doses and the MTD was 18 μg/kg/dose. Dose-limiting toxicity (DLT) included grade 3 urticaria (1 pt) and grade 3 vascular leak syndrome (2 pts). To allow further SS1P dose escalation 17 pts were treated on the QOD x 3 schedule and the MTD was 45 μg/kg/dose. The DLT was grade 3 pleuritis and was seen in 2/2 pts treated at a dose of 60 μg/kg and in 1/9 pts treated at a dose of 45 μg/kg. In all cases the pleuritis resolved completely. No grade 4 toxicity was observed. The most common grade 1/2 toxicities included hypoalbuminemia (21 pts), fatigue (17 pts), fever (9 pts) and edema (9 pts). At the MTD of 45 μg/kg the mean Cmax of SS1P was 483 ng/ml and half-life was 466 minutes. Of the 33 evaluable pts treated, 4 had minor response, 18 had stable disease and 11 had progressive disease. Two pts with stable disease had complete resolution of their ascites. A pt with peritoneal mesothelioma had complete resolution of her abdominal ascites, required no further therapy and died of unrelated causes 5 years after SS1P treatment. In the other pt with ovarian cancer there was resolution of abdominal and pelvic ascites that lasted 6 months. Conclusion: SS1P is well tolerated with pleuritis as the DLT at the highest dose level. Anti-tumor activity was noted in a group of heavily pretreated patients. Based on pre-clinical studies that show marked synergy between SS1P and chemotherapy, phase II clinical trials of SS1P in combination with chemotherapy for the treatment of mesothelin expressing cancers will open in 2007.

No significant financial relationships to disclose.

Current treatment options and biology of peritoneal mesothelioma: meeting summary of the first NIH peritoneal mesothelioma conference

Peritoneal mesothelioma is a rare cancer of the peritoneum with about 250 new cases diagnosed each year in the United States. It is the second most common site for mesothelioma development and accounts for 10-20% of all mesotheliomas diagnosed in the United States. A meeting sponsored by the NIH Office of Rare Diseases was held in Bethesda, Maryland on September 13 and 14, 2004. The objective of this meeting was to review the epidemiology, biology and current surgical and medical management of peritoneal mesothelioma. In addition, the meeting also discussed clinical and pre-clinical evaluation of novel treatments for mesothelioma as well as ongoing laboratory research to better understand this disease. This report summarizes the proceedings of the meeting as well as directions for future clinical and basic research.

p53 protein expression does not correlate with EBV status in childhood B non-Hodgkin lymphomas

BACKGROUND

The p53 tumor suppressor gene is affected in a wide range of human cancers, including hematological malignancies. This gene encodes a nuclear phosphoprotein p53, which plays a key role in cell cycle arrest, induction of apoptosis, and DNA repair. Mutations of the p53 gene often lead to the accumulation of the mutated protein in the nucleus of neoplastic cells. However, p53 protein expression is frequently detected in non-Hodgkin lymphomas (NHL) without any correlation with p53 mutations. This discordance suggests the existence of other mechanisms to stabilize the p53 protein, including binding of p53 protein to viral proteins. p53 protein has been shown to bind to proteins encoded by the Epstein-Barr virus (EBV).

PROCEDURE

The aim of this study was to analyze p53 expression in childhood B-NHL and correlate its expression in the absence of p53 mutations with EBV in order to investigate a possible involvement of EBV in p53 stabilization.

DESIGNS AND METHODS

Tumor specimens from 35 children with B-NHL were analyzed by immunohistochemistry (IHC) with the DO7 monoclonal antibody, which recognizes an epitope at N-terminus of p53 protein and reacts with wild type and mutant proteins. To detect p53 mutations, PCR/SSCP and sequencing were performed. EBV status was determinated using a specific PCR technique.

RESULTS

The overall frequency of p53 immunostaining positivity was 45% (16 of 35). p53 mutations were detected in nine patients (25.6%). p53 immunoreactivity was observed in all cases with mutations. Additionally, we identified 7 p53 positive cases among 26 tumors without mutations. EBV DNA was detected in 24 of 35 cases. Four patients with p53 expression dissociated from mutation were EBV positive. No statistically significant association was found between p53 expression and EBV cases despite the exclusion of those patients in which p53 expression was related with p53 mutations (P = 0.28 and 0.54, respectively).

CONCLUSIONS

Our results suggested that in childhood B-NHL, the expression of p53 dissociated from mutations could not be related to EBV infection. Further studies with larger patient sets will be necessary to determinate if EBV-encoded protein may play a role for nuclear accumulation of p53 protein.