We report a case of a late response to splenectomy in a patient who was diagnosed with ITP at another center in 1991 at the age of 23 years. At primary diagnosis, a comprehensive work-up for underlying disorders was unremarkable, except for slight positivity for antinuclear antibodies (ANA). The patient was initially prescribed prednisone at a dosage of 1 mg/kg body weight/day; after approximately 1 year, the dosage was appropriately tapered and administration of the steroid was eventually stopped. However, shortly thereafter, the patient experienced a relapse of ITP. She refused splenectomy; therefore, prednisone was restarted and continued at the lowest effective dosage (25-30 mg/day) that allowed stable maintenance of a platelet count >30×10⁹/L until 2006. During this time, she was followed up at different hematologic centers. In 2006, the patient was reevaluated because of unresponsiveness to prednisone and was found to have heterozygous factor V Leiden mutation, with no other abnormalities. She refused splenectomy once again. Therefore, cyclosporin A was administered as second-line treatment at a dosage of 200 mg/day, and a stable increase in the platelet count (>50×10⁹/L) was achieved.

In December 2010, the patient developed hypertension for which she received antihypertensive therapy and presented to our hospital in June 2011. A comprehensive work-up revealed hypertension and mild renal failure that were related to cyclosporin A. Other underlying or associated medical conditions were carefully excluded. In particular, comprehensive laboratory panel results for autoimmunity, including ANA, were negative; serological test results for HIV and hepatitis viruses were also negative. Therefore, cyclosporin A was discontinued and prednisone was restarted. Following the hypertensive crisis, the patient was admitted with a platelet count of 15×10⁹/L and intravenous immunoglobulin (IVIG) was administered. In November 2011 (21 years after the primary ITP diagnosis), at the age of 44 years, the patient underwent laparoscopic splenectomy with IVIG and enoxaparin prophylaxis. After the procedure, the patient developed pneumonia and acute pulmonary embolism and was admitted to the intensive care unit (ICU); however, after laparoscopic splenectomy, the platelet count did not increase and additional IVIG was required. The patient was discharged from the ICU on full enoxaparin alone for 6 months. Following laparoscopic splenectomy, the platelet count spontaneously increased to >50×10⁹/L and >100×10⁹/L after 2 and 7 months, respectively. The patient is well and active approximately 2 years and 22 years after laparoscopic splenectomy and ITP diagnosis, respectively; her most recent platelet count was 550×10⁹/L, for which she is receiving low-dose acetylsalicylic acid.

Our case outlines the effective role of splenectomy in advanced and long-term ITP as well as the possible occurrence of a late response to the procedure. Adult ITP patients who experience a relapse after initial corticosteroid treatment present a therapeutic challenge [1]. The current guidelines recommend splenectomy in this setting; indeed, it results in a high rate of durable responses and the possibility of a definitive cure in a remarkable proportion of patients [1]. However, ITP patients may be at increased risk of perioperative and long-term complications, such as venous thromboembolism and sepsis [4]. These concerns should be considered in the selection of newer available treatments that could potentially allow deferment of splenectomy but do not offer complete amelioration [5].

In the present case, the patient maintained a sustained response 2 years after splenectomy, although the follow-up period was not sufficient to consider her definitively cured. As in our case, the decision to proceed to splenectomy should be patient-specific and performed after the patient has been adequately informed of the potential risks and benefits of the procedure compared with those of alternative treatment options, including the newer thrombopoietin-receptor agonists that require continuous administration to effectively maintain platelet count responses without possibility of complete amelioration.

In conclusion, we report a specific post-splenectomy outcome, characterized by a slow and delayed increase in platelet count, in a patient with long-term, advanced, and steroid-refractory ITP who could not continue treatment with cyclosporin A because of the significant toxicity induced by this agent. The platelet count after splenectomy is considered an important prognostic factor; in particular, a high platelet count on day 7 and in the third month has been reported as predictors of long-term response [2, 3]. Our patient experienced a very slow increase in platelet count; indeed, following laparoscopic splenectomy, the platelet count spontaneously increased to >50×10⁹/L and >100×10⁹/L after 2 and 7 months, respectively. This particular platelet kinetics have not been fully understood and are attributed to a potential detrimental effect on megakaryocytopoiesis by the medical complications experienced by our patient, such as pulmonary embolism and infection.