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Indian Pediatr 2013;50: 611 |
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Very Low-dose Intravenous Immunoglobulin for
Treatment of Immune Thrombocytopenic Purpura
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Vikas Dua
Department of Pediatric Hematology Oncology, Action
Cancer Hospital, Delhi, India.
Email: [email protected]
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Treatment of immune thrombocytopenic purpura (ITP) is a
controversial subject. The management varies widely, ranging
from observation only, to aggressive management with
corticosteroids, intravenous anti-D rhesus, intravenous
immunoglobulin (IVIG), rituximab, splenectomy, etc. The
British Society for Hematology and American Society of
Hematology have developed ITP management guidelines [1].
It was first reported in 1981 by Dr. Paul
Imbach that high doses of IVIG promote fast recovery of ITP
in children. The mechanism of action of IVIG remains as yet
incompletely understood [2]. For pediatric patients
requiring treatment, a single dose of IVIg (0.8 to 1 g/kg)
can be used as first line treatment [3]. We report a case of
ITP treated with very low-single dose of IVIG (100 mg/kg).
A nine-year-old boy presented to us with
complaints of fever, cough and pin point red spots over the
body for 2 days. He also had one episode of bleeding from
nose. On examination he had petechial spots scattered all
over the body. There was no hepato-splenomegaly. Complete
blood count showed haemoglobin of 11.4 g/dL, white blood
cell 8000/mm 3
and platelet 8,000/mm3.
Peripheral blood smear was normal other than severe
thrombocytopenia and large platelets. The bone marrow
examination showed megakaryocytes, which were present in
increased numbers. Patient was started on IV
methylprednisolone (20 mg/kg/day) for 3 day then switched to
oral prednisolone. With this treatment, platelet count
increased to 45000/mm3.
Patient again presented after 10 days with platelet counts
of 10,000, multiple petechial spots and gum bleeding.
Patient was started on intravenous anti-D rhesus (75 µg/kg)
but no response was noted. At this stage it was planned to
give IVIG but due to cost constraints, patient was given
single very low dose of IVIG (100 mg/kg). Bleeding stopped
and platelet count increased to 26,000/mm3
after 1 day, 68,000/mm3
after 2 days, 140,000/mm3
after 3 days of IVIG therapy. Four weeks after therapy
platelet count was 72,000/mm3.
Till date there is only one paper
concluding that treatment with very low-dose (200mg/kg) IVIG
according to individual clinical response is effective and
safe in childhood acute ITP [4]. With 1 g/kg dose itself,
only 2/3rd of responders will have a sustained response. The
remaining 1/3rd will relapse after 6 weeks. Whether the
sustained response rate is going to be further lower with
100 mg/kg dose is a question to be explored.
ITP behaves differently in different
children. Some respond to steroids, some to IVIG and some to
neither. Presumably this is related to the amount of
antiplatelet antibody production. We hypothesize that some
children may have a relatively lower antibody load and may
hence respond to lower doses of IVIG. Further studies are
needed to evaluate the efficacy of very low dose IVIG in
children with ITP.
References
1. Shad AT, Gonzalez CE, Sandler SG.
Treatment of immune thrombocytopenic purpura in children:
current concepts. Paediatr Drugs. 2005;7:325-6.
2. Lazarus AH. Mechanism of action of
IVIG in ITP. Vox Sang. 2002;83:53-5.
3. Neunert C, Lim W, Crowther M, Cohen A,
Solberg L Jr, Crowther MA, et al. The American
Society of Hematology 2011 evidence-based practice guideline
for immune thrombocytopenia. Blood. 2011;117:4190-207.
4 Lee JH, Lee KS .Efficacy of Very Low-dose (200 mg/kg/d)
with Short-term Intravenous Immunoglobulin G Therapy
according to Individual Response of Acute Immune
Thrombocytopenic Purpura in Childhood. Clin Pediatr Hematol
Oncol. 2006; 13:143-9.
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