Human herpesvirus-8 infection in Tunisian adult acute leukemia patients.

Background: Human herpesvirus 8 (HHV-8) has been linked to the development of Kaposi's sarcoma (KS)and multiple other hematologic malignant disorders. However, the role of HHV-8 in acute leukemia patients is unknown. Objectives: The objective of this study was to determine the prevalence of HHV-8 in Tunisian acute leukemia patients and in healthy blood donors. Methods: An indirect immunofluorescence test was used to detect the presence of anti-HHV8 antibodies. Nested PCR was used for the detection of HHV-8 DNAemia in samples of plasma. Results: The seroprevalence of HHV-8 was significantly higher in acute leukemia patients (21,4% ,15/70) than in healthy blood donors (7,1%, 5/70), (p= 0.02). Gender, type of disease, status of disease, prior blood transfusion, and outcome were not associated with HHV-8 seroprevalence. However, among acute leukemia patients, HHV-8 seroprevalence was statistically associated with older age > 40 years of age, (p=0.002). HHV-8 DNAemia was detected (1,4%) in only one patient of acute myeloid leukemia (AML) and none of the healthy blood donors. Conclusions: The seroprevalence of HHV-8 infection in Tunisian adult acute leukemia patients was three times as high compared to healthy blood donors, suggesting that patients with acute leukemia might be at increased risk of HHV-8 infection.

miR-146a, miR-196a2, miR-499, and miR-149 linked with susceptibility to acute lymphoblastic leukemia: A case-control study in Tunisia.

BACKGROUND: MicroRNAs (miRNAs) are promising biomarkers of hematological malignancies, including acute lymphoblastic leukaemia (ALL). Recent studies revealed that miRNA single nucleotide polymorphisms (miR-SNP) modulate cancer risk by regulating various signaling pathways. However, their association with altered risk of ALL yielded inconsistent results. OBJECTIVE: This study aims to investigate the association of four miR-SNPs with altered risk of ALL risk in Tunisian, the first on North African population. METHODS: A retrospective case-control study exploring the association of miR-146a, miR-196a2, miR-499, and miR-149 SNPs in 126 ALL patients and 126 healthy controls. RESULTS: Of the tested variants, significantly lower minor allele frequencies (MAF) of miR-146a C-allele and higher MAF frequency of miR-149 T-allele (P = 0.006) were seen in ALL cases. The association of miR-149 rs2292832 (Pc = 0.02), but not miR-146a rs2910164 (Pc = 0.11) persisted after correcting for multiple comparisons. Significantly reduced prevalence of miR-146a G/C genotype and higher frequency of miR-149 C/T genotype were seen in ALL cases vs. control subjects, which translated into negative association of miR-146a (rs2910164) with ALL according to the codominant and dominant models. Similarly, miR-149 (rs2292832) was positively associated with ALL according to the codominant and dominant genetic models. Three combinations comprising miR-146a/miR-196a2 GG vs CT + TT genotype combination, miR-146a/miR-499 GG vs TC + CC genotype combination, and miR-146a/miR-149 GG vs CT + TT genotype combination, were less frequent in ALL patients than in controls, and were negatively associated with the presence of ALL. CONCLUSION: Our study suggests that miR-146a and miR-149 polymorphisms constitute biomarkers for personalized diagnosis of ALL.

Cytomegalovirus Glycoprotein Polymorphisms and Increasing Viral Load in Non-Transplant Patients with Hematological Malignancies Undergoing Chemotherapy: A Prospective Observational Study.

INTRODUCTION: Cytomegalovirus (CMV) predisposes to several clinical complications and is a major cause of morbidity and mortality in immunocompromised patients, including patients with hematological malignancies (HM). The present study was carried out to determine the distribution of CMV glycoprotein B, N, and O (gB, gN, and gO) genotypes and their potential effect on its viral load and on clinical outcomes in a cohort of Tunisian non-hematopoietic stem cell transplant (HSCT) patients with HM undergoing chemotherapy. METHODS: CMV viral load was evaluated by real-time quantitative PCR. The gB, gN, and gO genotypes of the CMV strains were analyzed by multiplex nested PCR and sequencing. RESULTS: This prospective study involved 60 clinical isolates obtained from 60 non-HSCT patients with HM undergoing chemotherapy. Mixed CMV gB, gN, and gO genotypes were the predominant glycoprotein genotypes in 31%, 41.4%, and 46.4% of patients, respectively. Mixed gB genotypes were associated with higher initial levels of CMV load (p = 0.001), increased rate of fever (0.025), and co-infection with other herpesviruses (HHVs) (p = 0.024) more frequently than in single gB genotype. Mixed gN genotypes were more associated with severe lymphopenia (ALC < 500/µL) (p = 0.01) and increased risk of death (p = 0.042) than single gN genotype. Single gO2b genotype had also a more unfavorable outcome (p = 0.009) than the other single gO genotype. Mixed gO genotypes were associated with female gender (p = 0.015), acute leukemia disease (p = 0.036), initial high level of CMV viral load (at least 1000 copies/mL) (p = 0.029), skin rash (p = 0.01) more frequently than in single gO genotype. The gO1a/gN3b linkage was associated with an increased initial viral load (p = 0.012). CONCLUSION: Infection with mixed CMV genotypes was common and multiple gB, gN, and gO genotypes were associated with clinical manifestation and higher viral load.

Co-infections of human herpesviruses (CMV, HHV-6, HHV-7 and EBV) in non-transplant acute leukemia patients undergoing chemotherapy.

BACKGROUND: Human herpesviruses (HHVs) remain latent after primary infection and can be reactivated in response to immunosuppression and chemotherapy. Little is known about their incidence, potential relationships, risk factors and clinical impact in non-transplant leukemia patients. This study investigated prospectively incidence, risk factors, clinical impact and possible association of HHVs-(1-7) infections in patients with newly diagnosed acute leukemia. METHODS: Study design involved longitudinal sampling before chemotherapy and in different phases of chemotherapy: post-induction, post-remission, and post-salvage during 2016-2018. A total of 734 plasma samples from 95 patients were analyzed by a qualitative, multiplex PCR for HHVs detection and a quantitative real-time PCR was used for cytomegalovirus (CMV) quantification. HHVs-(1-6) IgG and IgM antibodies were tested using immunoassays. Risk factors were analyzed by binary logistic regression and relationships between viruses were analyzed using the Chi-square or Fisher's exact test as appropriate. RESULTS: The overall seroprevalences of HHV-(1-6) IgG were high (> 80%). At least one herpes viral agent was detected in 60 patients (63.3%). CMV was the most commonly detected virus in the different phases of chemotherapy (19.4%), followed by HHV-6 (9.7%), HHV-7 (5.2%) and EBV (2.7%). HSV-1/2 and VZV DNA were not detected. Twenty-seven patients (28.4%) had more than one virus detected in the follow-up, with 23 who were co-infected. CMV/HHV-6 was the most frequent co-infection (69.5%, 16/23). HHV-6 infection (p = 0.008) was identified as a risk factor for CMV infection while salvage treatment (p = 0.04) and CMV infection (p = 0.007) were found to be independent risk factors for HHV-6 infection. CMV co-infection was associated with severe lymphopenia with an absolute lymphocyte count (ALC) (< 500/µL) (p = 0.009), rash (p = 0.011), pneumonia (p = 0.016) and opportunistic infections [bacteremia, p < 0.001 and invasive fungal infection, (p = 0.024)] more frequently than CMV mono-viral infections. CONCLUSIONS: Our data suggest that co-infection with HHVs, especially CMV and HHV-6, may contribute to the development of serious clinical manifestations with profound lymphopenia, pneumonia rash and increased risk for bacterial and fungal co-infections. These findings may suggest the synergistic effect of HHVs associated infection.

ARLTS1, potential candidate gene in familial aggregation of hematological malignancies.

INTRODUCTION: Genetic predisposition to familial hematological malignancies was previously described through several epidemiological analyses, but the genetic basis remains unclear. The tumor-suppressor ARLTS1 gene was previously described in sporadic hematological malignancies and familial cancer context. METHODS: In this study, we sequence the ARLTS1 gene in 100 patients belonging to 88 independent Tunisian and French families. RESULTS: After gene sequencing, we report 8 genetic variations, most of which were previously reported in several cancer forms. The most common variants were W149X and C148R and were previously associated to B-cell chronic lymphocytic leukemia and to high-risk of familial breast cancer. CONCLUSIONS: These results emphasize the fact that ARLTS1 gene mutations can be considered as a potential predisposing factor in familial hematological malignancies and other several cancer forms.

Combined IKZF1 and IG markers as new tools for diagnosis and minimal residual disease assessment in Tunisian B-ALL.

INTRODUCTION: The monitoring of minimal residual disease (MRD) approach in patients diagnosed with B-acute lymphoblastic leukemia (B-ALL) allows an early detection of residual clones inducing relapses and therefore appropriate therapy strategy. The molecular markers may identify and quantify the residual blasts in B-ALL with normal cytology. In this study, we aimed to use combined IKZF1, IGH and IGK immunoglobulin genes for diagnosis and MRD monitoring in B-ALL sample using MLPA, multiplex PCR and real-time quantitative PCR. MATERIAL: We showed that multiplex PCR and MLPA are necessary and complementary to detect IKZF1 deletions. RESULTS: We have identified at the diagnosis clonal IGH rearrangement (VH3-JH5) and IKZF1 deletion (Δ4-7), which we have used it for MRD evaluation after induction chemotherapy. Despite the absence of chromosome abnormality, the patient may be classified in high-risk group with a relapse rate of residual blasts>10-4 and sensitivity up to 10-5. This molecular approach enabled the patient's stratification, which was overlooked by classical methods. CONCLUSION: The combined IKZF1 and immunoglobulin genes will be used as appropriate molecular tools for diagnosis and MRD assessment of B-lineage leukemias and introduced as a routine tests in Tunisian clinical laboratories. They will be useful to stratify patients into risk groups leading to better treatment strategy.

Analysis of the clinico-hematological relevance of the breakpoint location within M-BCR in chronic myeloid leukemia.

The Philadelphia chromosome (Ph) derives from the balanced translocation between chromosomes 9 and 22. This chromosomal translocation results in the fusion between the 5' part of the BCR gene, normally located on chromosome 22, and the 3' part of the ABL gene on chromosome 9 giving origin to a BCR-ABL fusion gene which is transcribed and then translated into a hybrid protein. In general, three breakpoint cluster regions in the BCR gene have been described: major (M-BCR), minor (m-BCR) and micro (µ-BCR). Three main variants of the BCR-ABL gene have been described depending on the length of the sequence of the BCR gene included that encode for the P190, P210, P230 proteins. Most patients (95 %) were found to have P210 protein that resulted from rearrangement in the M-BCR region in the BCR gene and thus gives rise to b2a2 or b3a2 variants. The incidence of one or other rearrangement in chronic myeloid leukemia (CML) patients varies in different reported series. These two variants are associated with distinct clinical types of human leukemias. In this study, we report the frequencies of M-BCR-ABL fusion transcripts in 44 CML patients and we review the data on the correlations between the type of M-BCR/ABL variant and the corresponding sex, age and biological features. Forty-four untreated chronic phase CML patients were studied. The type of BCR-ABL fusion transcripts was determined by reverse transcriptase polymerase chain reaction (RT-PCR). More than half of them showed b3a2 fusion transcript (64 %), while (36 %) showed b2a2 transcript. No patients coexpressed b3a2/b2a2. Correlation between biological data demonstrated that: (a) M-BCR rearrangements were not associated with the sex of the patients. (b) Patients with b3a2 rearrangements were older than patients with b2a2 transcripts. (c) M-BCR rearrangements were influenced neither by the white blood count (WBC) nor with hemoglobin levels. However, platelet level is more elevated in patients with b3a2 transcript (681.2/L vs. 207/L; P = 0.001). In conclusion, we observed significant correlations between age, platelet level and M-BCR-ABL transcript, these observations deserve further investigations.

Nasopharyngeal/nasal type NK/T lymphoma: analysis of 23 cases and current review of the literature.

OBJECTIVES: This study aims to identify the presenting symptoms, treatment and outcome of patients with nasal natural killer T (NK/T)-cell lymphoma and to find possible differences in survival based on Ann-Arbor stage and international prognostic index (IPI). PATIENTS AND METHODS: Computed tomography and biopsy results of 23 patients (15 males, 8 females; mean age 41 years; range 22 to 72 years) with extranodal NK/T-cell lymphoma who were treated at the department of clinical hematology between 1995 and 2011 were retrospectively analyzed. RESULTS: The median time from onset of clinical symptoms to histological diagnosis was five months. Most patients presented with nasal obstruction (69%) and rhinism (52%). The site of extranodal NK/T-cell lymphoma primarily involved nasal cavity in 39%. Orbital extension was observed in 26%. Lymphomas were classified as stage IE in 30.4%, stage IIE in 47.8% and stage IVE in 21.7%. Nineteen patients received treatment: 10 received chemotherapy plus radiotherapy, nine received chemotherapy only. We used several regimens of chemotherapy including some protocols containing etoposid, L-asparaginase and others without this drugs. Univariate analysis showed that lower IPI score, low Ann-Arbor stage and responsiveness to treatment with both chemotherapy and radiotherapy were significant factors influencing both OS and PFS. CONCLUSION: Nasal type NK/T-cell lymphoma showed a poor response to the conventional anthracycline-based chemotherapy, thereby an investigation for a novel therapy is urgently needed to improve survival.