Autoimmune Disease May Have Complicated Treatment for Pediatric ITP

Matthew Henderson, DO

An underlying autoimmune condition may have played a role in making a 13-year-old patient refractory to treatment for immune thrombocytopenia (ITP) according to findings from a case study presented at the 2018 American Society of Pediatric Hematology/Oncology Conference.¹

Investigators were unable to determine whether exposure to several immune regulatory drugs or the autoimmune condition, dermatomyositis with calcinosis, interfered with the ITP treatment. Furthermore, the patient experienced significant bleeding, which prevented investigators from fully evaluating her response to second-line treatment.

“It’s a very interesting case,” said coauthor Matthew Henderson, DO, a pediatric hematology/oncology fellow at Akron Children’s Hospital. “Not only do you have a child who has an underlying autoimmunity—there aren’t many case reports out there with dermatomyositis in ITP—but then to have a child, on top of that, to have the rare bleeding sequelae along with ITP is very complicated.”

Henderson said the girl presented with what appeared to be ITP, but her disease was complicated by the presence of dermatomyositis, an autoimmune condition she had since she was a toddler. The patient was taking the immunosuppressant cyclosporine and hydroxychloroquine, a disease-modifying antirheumatic drug, to treat her dermatomyositis.

She was diagnosed with new onset wet purpura, ecchymosis hematuria, bloody drainage from a previous incision and drainage, and thrombocytopenia of 1 x 10⁹/L. Physicians also determined that she had a small punctate hemorrhage. Treatment with methotrexate, intravenous immunoglobulin, and high-dose steroids did not increase her platelet count.

By day 19, following a course of oral prednisone and eltrombopag (Promacta), she developed hematochezia, melena, and a new onset anemia, and a red blood cell scan identified a gastrointestinal bleed. She was assigned to an esomeprazole drip, aminocaproic acid, platelet transfusions, rituximab (Rituxan), and recombinant coagulation factor VIIa, but her bleeding did not improve.

At day 25, she had developed a new headache with vomiting and physicians detected a “significant” intracranial hemorrhage (ICH) on computed tomography. ICH has an incidence of 0.19% to 0.78% in patients with ITP, and appears within the first week of diagnosis in 45% of patients.

“Bleeding is not something we usually expect with an ITP patient, but she ended up not only having GI bleeding but also had an intracranial bleed,” Henderson said. “She had a platelet count of 1 [x 10⁹/L] so we had to do something.”

Henderson said surgeons were convinced to perform an emergent splenectomy—which can be curative or, at minimum, could result in an increased platelet count—along with concurrent continuous platelet transfusion. There are no consensus guidelines regarding the role of splenectomy in patients with ITP, but it has been used to treat severe bleeding, chronic ITP, and refractory ITP.

Results from a study of 73 patients with refractory ITP published in the International Journal of Surgery in 2014 showed that, within 5 days after splenectomy, the mean postoperative platelet count rose from 89,000 ± 72,000/μL to 321,000 ± 237,000/μL. The overall response rate was 87.5% with a complete response (CR) rate of 77.8%.² At a median follow-up of 32 months, 61.1% of patients had stable remission and did not need further treatment for ITP.

Surgery was successful for the 13-year-old patient, though she continued to have more complications. Two weeks after surgery, she developed severe thrombocytosis that resulted in portal venous, diffuse mesenteric, and splenic thrombosis that was treated enoxaparin sodium.

Henderson said that, ultimately, the patient is alive and did well through the total course of treatment. She was negative for paroxysmal nocturnal hematuria, a rare acquired hematopoietic stem cell disorder, and her ICH improved despite treatment with enoxaparin sodium. The anticoagulant has been associated with increased risk for ICH.³

Henderson said that there are a good number of case studies exploring dermatomyositis and ITP in adult patients, but the literature is not as well developed in pediatric patients. While it is impossible to draw conclusions from a case study involving a single patient, he said that it will be important to learn how children and young adults respond to therapy.

“There’s a lot of literature looking at children with lupus or scleroderma who develop ITP and how to manage those patients,” he added. “Looking at dermatomyositis as another condition and relating that to the ITP field is important.”

References

1. Wright E, Henderson M, Patton D, Savelli S. Management of bleeding in a patient with juvenile dermatomyositis and unresponsive immune thrombocytopenia. Presented at: the 2018 ASPHO Conference; May 2-5, 2018; Pittsburgh, PA. Poster 106.
2. Rijcken E, Mees ST, Bispin G, et al. Laparoscopic splenectomy for medically refractory immune thrombocytopenia (ITP): a retrospective cohort study on longtime response predicting factors based on consensus criteria. Int J Surg. 2014; 12(12):1428-33. doi: 10.1016/j.ijsu.2014.10.012.
3. Lovenox [prescribing information]. Bridgewater, NJ: sanofi-aventis U.S. LLC; 2017. http://products.sanofi.us/lovenox/lovenox.html#Boxed%20Warning. Accessed May 14, 2018.