Abstract:
Immune thrombocytopenic purpura (ITP) is an autoimmune disease presents
with isolated thrombocytopenia (thrombocyte count <
100.000/mm3) and develops due to increased thrombocyte destruction by
autoantibodies. ITP is the most common cause of pediatric
thrombocytopenia. Usually a self-limiting disease with an acute course
of 70% - 80%. However, 20% - 25% cases are chronical. These cases
are follow-up and management difficult and expensive. It is important to
distinguish events that may become chronic at the time of initial
diagnosis. In this study, we sought clues to be able to choose, which
the patient will be chronicle?
Background: Immune thrombocytopenic purpura (ITP) is an
autoimmune disease present with isolated thrombocytopenia and develops
due to increased thrombocyte destruction by autoantibodies.(1, 2) ITP is
the most common cause of pediatric thrombocytopenia. Usually a
self-limiting disease with an acute course of 70% - 80%. However,
20-30% of cases become chronic. ITP most commonly seen between 2 and 5
years of age but occurs in all pediatric age groups. (2, 3)
In this study, we aimed to investigate the main characteristics
(features) and outcomes of our pediatric ITP cases and whether there are
any factors affecting chronicity.
Procedure: We analyzed retrospectively our 184 newly diagnosed
pediatric ITP cases. In this study, a history of viral infections and
vaccination, physical examination, laboratory findings, treatment
modality, and efficacy in children under 18-years old with ITP were
recorded. Thrombocytopenia persisting beyond 12 months was defined as
”chronic ITP” whereas resolved thrombocytopenia within 12 months of
diagnosis was defined as ”acute ITP”. The patients were divided into
three age groups. Group 1 include the patients younger (smaller) than 2
years of age (57 patients), group 2 include the patients between 2 and 6
years of age (73 patients), and group 3 include the patients older
(greater) than 6 years of age (54 patients). We evaluated the role of
clinical and laboratory findings and treatment modalities in the
chronicity of ITP.
As first-line treatment, 87 (47.3%) of patients were given Intravenous
Immune Globulin ( IVIG, 1 g/kg, 1 or 2 days), 65 (35.3%) were given
methylprednisolone (20 mg/kg/day for three days, and 10 mg/kg/day for
four days), and 32 (17.4%) of patients were followed without any
medication.
Results: One hundred four patients were male (56.5%) and 80
(45.5%) were female. The mean age of patients was 5.4 ± 4.75 years at
diagnosis. The most common bleeding site was skin in 83,7% of patients
and none of the patients had central nervous system bleeding. In 92
patients (50%) no triggering cause could be identified. The most common
triggering factor was upper respiratory tract infection (in 34,2 % of
patients).
Thirty-nine patients (21.1%) who had persistent thrombocytopenia after
12 months of follow-up were accepted as chronic ITP. The ratio of
acute/chronic ITP cases was 83/21 in males, and 62/18 in females
(p=0.7). The treatment modality at first admission did not affect the
development of chronic ITP (p=0.61). The most important factor in the
development of chronic ITP was the age at diagnosis. The mean age at
diagnosis was 4.54±4.18 years in acute ITP and 8.62±5.39 years in
chronic ITP (p<0.0001)
Acute and chronic ITP ratio were 53/4 for patients less than 2 years of
age, 60/13 for patients between 2 and 6 years of age, and 31/23 for over
than 6 years of age
(p<0.0001). The
thrombocyte counts and mean platelet volume (MPV) at diagnosis did not
affect chronicity. Total leukocyte count at diagnosis had also no effect
on chronicity, but mean absolute
neutrophil count (ANC) was significantly higher (p=0.007) and mean
absolute lymphocyte count (ALC) was significantly lower
(p<0.0001) in chronic ITP patients. But when these findings
were re-evaluated according to each age group, we did not find any
important differences between acute and chronic cases for mean ANC and
ALC, except ALC levels had only a small effect on the
2nd (2-6 years) group (p:0.048).
Conclusions: Although ITP has a good prognosis in most of the
patient in childhood, it may become chronic in about 20 % of patients.
Our results support that, high age most important factor for ITP’s
chronicity. Infantile ITP prognosis better than older children, and
watch-and-wait strategy could be a safe treatment choice.