Discussion
Two impressive facts were indicated in this case, namely, splenectomy
resolved intractable AIHA in TKS, and chronic macrothrombocytopenia was
unexpectedly resolved.
This case suggests that refractory AIHA can be improved by splenectomy.
Splenectomy is performed in 15% of the AIHA patients in our country
(25%–57% in western countries), and its short-term effectiveness is
60%. The first-line therapy for warm type AIHA is prednisolone. For
patients who are resistant or require high-dose prednisolone treatments,
rituximab is selected as a second-line therapy.9Splenectomy is positioned as another option for second-line therapy, and
is thought to be the most effective conventional treatment for AIHA to
be proposed for patients unresponsive to
prednisolone.10 In this case, the patient was
resistant to prednisolone and rituximab, and the uncontrollable AIHA
pathology exacerbated hypersplenism. Increased splenic sequestration of
platelets and red cells led to severe anaemia and thrombocytopenia, and
therefore, splenectomy was performed as the next second-line therapy.
After splenectomy, intractable anaemia improved, never requiring red
blood cell transfusion until the present time.
Chronic macrothrombocytopenia also was improved by splenectomy.
Generally, inherited thrombocytopenia is caused by the impaired
production of platelets from megakaryocytes.11 Giant
platelets in TKS suggest disturbance of platelet
production,11 but pathophysiology of
macrothrombocytopenia in TKS still remains insufficiently elucidated.
Previous studies revealed a possible relationship between
Wiskott-Aldrich syndrome (WAS) and TKS, as CDC42 directly interacts with
the WAS protein.5,7,12 Thrombocytopenia in WAS is
caused by an increased clearance of platelets by the reticuloendothelial
system and a premature, ectopic release of platelets in the bone
marrow8; TKS may be suggested to have a common
pathology, but to clarify the mechanisms of macrothrombocytopenia in
TKS, further studies are required. Splenectomy has been believed to be
contraindicated for treating inherited thrombocytopenia, but the
recovery of platelet counts after splenectomy in our patient suggests
that an increase in platelet destruction in the spleen contributed to
thrombocytopenia. The observations in our patient may provide a novel
option for the treatment of TKS. Furthermore, our results might propose
a revision of treatment options for inherited thrombocytopenia.
Our case report concludes that splenectomy resolved both refractory AIHA
and chronic macrothrombocytopenia. Splenectomy can be suggested as a
treatment option for not only refractory AIHA, but also for
macrothrombocytopenia in TKS. As this is still the first case, further
studies are required to conclude the efficacy, safety, and effects of
splenectomy in these cases.