الفهرس 
CytomegalovirusOnly 14 pages are availabe for public view
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Abstract
Human Cytomegalovirus is a significant cause of morbidity and
mortality in immunocompromised patients. After primary infection even if
in apparent , the virus persists in the host for a long period of time and can
be reactivated in immunosuppression, after massive blood transfusion, under
intensive chemotherapy and tissue transplantation.
The aim of this study is detecting prevalence of active HCMV infection
among immunocompromised pediatric cancer patients, Comparing the
sensitivity and specificity of quantitative Real time-PCR and qualitative
PCR in the monitoring of active CMV infection. As well as their positive
and negative predictive values.More over, this study can be helpful in
Investigating the correlation between HCMV viral load in the clinical
specimens and severity of the disease, according to the clinical HCMV
scoring system as well as some clinical and hematological parameters that
may lead to fatal outcome among cancer patients.
In this study, 50 leukemic patients (40 ALL and 10 AML) and 30
normal control have been studied for the detection of the following assays;
CMV IgG , CMV IgM by ELISA, conventional PCR and quantitative CMV
by RT PCR assay.Briefly we can summarize our results in the following points:
• Our selected patients were febrile and had signs of viral infections,also
had organomegaly 35(70%) and chest infection 50(100%) .Median
duration of febrile neutropenia was 26.5 day ranged (9-60 days) ,among
half of our patients had more than the median value, Thirty percent of
our patients had abnormal level of AST and 94 percent had abnormal
level of LDH.The hematological parameters reveald that , 80% of
patients had low hemoglobin, 22% low TLC , 46% lymphopenia, 84%
neutropenia , 58% monocytopenia and 80% thrombocytopenia.these
values were mointered in our patients.
• The percentage of CMV positivity by conventional PCR in serum was
(54 %and 46.7%) in both leukemic patients and control, respectively. On
the other hand , the positivity of CMV in leukocyte was (38% and 40%)
in leukemic patients and control group respectively, According to high
positivity of CMV in serum, conventiol PCR was used as a gold standard
technique.
• Detection of CMV DNA by quantitative real time PCR, showing the
positivity of CMV DNA 19/50(38%) in serum of leukemic patients,
while in control group it was 14/30 (46.6%) with no significant
difference between them (P value=0.446). Further more, the
Determination of viral load among 19 positive HCMV DNA serum
samples of patients and 14 of controls was done by quantitative RT PCR
revealing a median viral load of 5.5x106 and 3.5x105 for patients andcontrols respectively, with a significant difference between the 2 groups
(p=0.001).
• Serological assays, on the other hand, showed that the Percentage of
leukemic children positive for CMV IgM was significantly lower than
that in the control group (11/50 22 % versus13/30 43.3%, P=0.044).
CMV IgG was detected in 90% of leukemic and control groups
respectively, (45/50 leukemias and 27/30 controls, p=1.00).
• Presence of HCMV infection in sera of leukemia and control groups by
serological and molecular assays is demonstrated. The results of qualitative
PCR showed the highest sensitivity, specificity and accuracy compared to
other assays(IgM,high IgG,quantitative PCR ) among leukemia
group.Considering qualitative PCR assay is the golden standard assay for
detection of active HCMV infection, efficacy of other different assays were
evaluated. Sensitivity, specificity, PPV, NPV and accuracy of the applied
diagnostic methods for CMV are demonstrated. Sensitivity of CMV IgM and
quantitative assay was lower in leukemic patients compared to control (40%
and 70% respectively for leukemic patients vs 85.7% and 100% respectively
for control group). In contrast sensitivity of high titer IgG was higher in
leukemic patients than control (80% vs 50% respectively).
• The leukemic patients who were viremic and had high IgG titer were more
associated with mucositis (P=0.06) though borderline, low count of TLC (<11950cells/cmm) (P=0.021) than those with positive IgM. Also, Presence of
CMV viral load was significantly associated with lymphopenia
(P=0.02).Presence of HCMV viremia was not associated with CMV disease
( p=0.967).
• Reciver operating characteristic curve (ROC ) curve analysis was performed
to identify leukemic patients who are at risk of development of severe CMV
disease and preemptive therapy is required. The estimated area under the
curve adjusted for CMV serum QPCR was 0.783 with statistical significance
(P = 0.037) indicating proper adjustment. The cutoff DNAemia value was at
3520000 copies/µL; this viral load was the best value to discriminate between
patients with high and low risk absolute lymphocytic count, with sensitivity
and specificity equal to 80% and 67%, respectively.
• In general,The results of the current study showed that severe CMV disease
highly associated with the low survival of pediatric leukemia patients
(P=0.002) also, the duration of febrile neutropenia (P=0.024),
thrombocytopenia (P=0.024), lymphopenia (P=0.042), neutropenia (P=0.044)
affected the survival status of these patients.