الفهرس 
Platelet Formation and PhysiologyOnly 14 pages are availabe for public view
 |  | from | 148 |  |  |
| | | from | 148 | | |
Abstract
Thrombocytopenia is a common clinical problem
manifested by decrease of platelet count which may be life
threatening sometimes. There are two major causes for
thrombocytopenia: Hyperdestructive thrombocytopenia and
Hypoproductive thrombocytopenia.
Diagnosis of both types of thrombocytopenia is based on
several laboratory investigations for discrimination between
them. Among these investigations are platelet indices which
are mean platelet volume (MPV), platelet distribution width
(PDW) and platelet large cell ratio (P-LCR).
The aim of this study was to evaluate the significance of
platelet indices in the diagnosis of thrombocytopenia by
comparing the levels in hyper-destructive thrombocytopenia
(ITP) and hypo-productive thrombocytopenia. The sensitivity
and specificity of platelet indices to enable the diagnosis of
ITP were also evaluated aiming to settle a cut off value for
MPV, PDW and P-LCR.
This study included eighty patients presented with
thrombocytopenia, classified as follows: group I included
forty patients with newly diagnosed idiopathic
thrombocytopenic purpura (ITP). group II included ten
patients with aplastic anemia (AA), 17 patients with acute
leukemia (AL), 3 patients with myelodyplasia (MDS) and 10
patients under treatment with chemotherapy. Patients were
recruited from Ain Shams University Hospitals in the clinical
and chemical pathology department. Twenty healthy age and
sex matched individuals were selected for comparison as
control group.
In ITP patients group, we found that the MPV and P-LCR
were significantly higher in comparison to either control group
or hypoproductive group.The best cut off value of MPV for differentiation between
ITP and hypoproductive thrombocytopenia was >9. 7 fl with a
diagnostic sensitivity 57. 5% and specificity 82. 5%, negative
predictive value 66% and positive predictive value 76. 6%,
while best cut off of P-LCR for differentiation between ITP
and hypoproductive thrombocytopenia was >33. 6 % with a
diagnostic sensitivity 100% and specificity 97. 5%, negative
predictive value 100% and positive predictive value 97. 6%.
A significant positive correlation was found between the
three platelet indices MPV, PDW and P-LCR in destructive
thrombocytopenia and hypoproductive thrombocytopenia,
while no significant correlation was found between platelet
count and the three platelet indices MPV, PDW and P-LCR
neither in ITP nor in hypoproductive thrombocytopenia.
As regard PAIgG detection revealed no significant
difference between patients and controls and between different
patient subgroups as well as low specificity and sensitivity to
diagnose ITP. Thus, not reliable as a routine test to diagnose
ITP.
Thus, our study concludes that increased MPV and PLCR
may provide a reliable positive diagnosis of ITP in case
of thrombocytopenic patients.
This study points to the importance of evaluating platelet
indices especially MPV and P-LCR to the thrombocytopenia
investigations as they provide a reliable positive diagnosis of
ITP
from this study, we could be concluded that:
- Measuring of platelet indices (MPV and P-LCR) provides
useful diagnostic test in differentiating ITP from
hypoproductive thrombocytopenia, thus may avoid the need
for bone marrow examination.
- PDW cannot be considered a differentiating measure in
distinguishing ITP from hypoproductive thrombocytopenia.
- Measurement of Platelet associated immunoglobulin G
(PAIgG) is not a reliable test in diagnosis of ITP.