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تشخيص مصلي وجزيئي لفيروس الحلا البشري النوع السادس المصاحب لبعض سرطانات الدم == Serological And Molecular Detection Of Human Herpesvirus Type 6 Associated With Certain Hematologic Malignancies
Author name:
هديل محمد فياض
Supervisor name:
علاء فاضل علوان | داود سلمان داود
General topic:
Medicine
Specific topic:
Microbiology
Degree:
Doctorate
University:
Mustansiriyah University
Language:
English
University location:
Baghdad
First pages:
19T1153 - p.pdf
Abstract:
Human herpesvirus 6 (HHV - 6) is largely ubiquitous double stranded DNA viruses within the betaherpesvirinae subfamily and of the genus Roseolovirus.HHV - 6A and HHV - 6B infects very high percentage of population around the world, primarily during childhood through respiratory droplets. HHV - 6 has been found out in many types of cancers : lymphomas, leukemia, cervical cancer, and brain tumors.This cross - sectional case control study was carried out in Baghdad Teaching Hospital and National Center of Hematology - AL - Mustansiriyah University - Baghdad, for the period from 1 September 2013 to 1 April 2015.The aims of the study were to explore the seropositivity rate of HHV - 6 antibodies among Iraqi patients with different hematological malignancies using different laboratory assays, beside, the molecular determination of plasma viral DNA load by quantitative polymerase chain reaction (qPCR).The study included 109 patients with different hematological malignancies; 24 patients with acute lymphoblastic leukemia (ALL), 30 patients with acute myeloid leukemia (AML), 11 patients with Hodgkin lymphoma (HL), 39 patients with non hodgkin lymphoma (NHL) and 5 patients with chronic lymphocytic leukemia(CLL). All patients were newly diagnosed and enrolled before receiving chemotherapy. The age range was between 14 - 80 years. Fifty three (48.6%) and 56 (51.4%) patients were males and females, respectively. The diagnosis of their malignancies was based on either bone marrow aspirate biopsy and lymph node biopsy as well as cytochemical investigations. Additionally, 59 apparently healthy blood donors were enrolled as control group. The age range was between 18 - 59 years, twenty eight (47.4%) and 31 (52.6%) were males and females, respectively.The serum anti - HHV - 6 IgG was detected by indirect immunofluorescent technique (IFAT) as well as by enzyme linked immunosorbant assay (ELISA).While, the serum anti - HHV - 6 IgM was detected by ELISA only. The detection and quantification of plasma viral DNAemia was carried out by quantitative polymerase chain reaction. Serological as well as molecular assays were done in Central Public Health Laboratory in Baghdad. The highest IFAT positivity rate was among patients with CLL (100%), followed by patients with AML (83.3%), and the least positivity rate was among patients with NHL (64.1%) compared to that of healthy control. Generally, the total anti - HHV - 6 IgG by IFAT was insignificantly higher among patients compared to healthy controls (74.3% vs 61.0%, p=0.074). The anti - HHV - 6 IgG positivity rates by ELISA were insignificantly higher in all groups of haematological malignancies except in patients with AML in whom it was significantly higher compared to healthy controls (96.7% vs 72.9%, p= 0.007 ). A part from AML, the highest anti - HHV - 6 IgG by ELISA was among patients with ALL (87.5%) followed by patients with NHL (84.6%), and the least was among patients with CLL (80.0%) compared to healthy control. Generally, the total anti - HHV - 6 IgG positivity rate detected by ELISA was significantly higher compared to IFAT in patients (p= 0.013) as well as in healthy control (p= 0.0005).The results of anti - HHV - 6 IgM positivity rate as detected by ELISA was significantly higher in patients with AML (36.7%, p=0.0004), and patients with HL (27.7%, p= 0.038) compared to healthy controls (6.8%). Whereas, other groups of hematological malignancies showed insignificantly higher positivity rate versus control group. However, the highest positivity rate was among patients with AML (36.7%), and the least positivity rate was among patients with CLL (0%). Generally, the total ELISA anti - HHV - 6 IgM positivity rate was significantly higher in patients versus healthy controls (22.0% vs 6.8%, p= 0.011). The results of PCR showed that 5 out of 109 patients had detectable HHV - 6 DNA in the plasma. The highest detection rate was among patients with HL (27.3%), followed by patients with ALL (4.2%), and then patients with AML (3.3%), while the virus was not detected in other disease categories as well as in healthy controls. The plasma viral load (mean ± SD) among the three Hodgkin lymphoma patients was 1.4± 0.3*102 particle/milliliter.The study concluded that the seropositivity rate of HHV - 6 infection is highly prevalent among Iraqi patients with hematological malignancies compared to healthy population. However, primary or reactivation infection as determined by anti - HHV - 6 IgM in patients as well as healthy individuals is relatively low. Furthermore, the HHV - 6 DNA detection rate as well as plasma viral load among malignant patients before receiving immunosuppressive treatment were low.
