How I manage cyclic thrombocytopenia

Incidental Diagnosis of Cyclic Thrombocytopenia: An Asymptomatic Case

Cyclic thrombocytopenia (CTP) is a very rare condition that is characterized by episodic thrombocytopenia over a period of three to five weeks. The pathogenesis of CTP is unclear and most likely heterogeneous; however, usually there is no clue about the underlying disease. In this case report, we presented a 48-year-old female who had a low platelet count of 66 x 103/µL (range: 150-450 x 103/µL) on her routine examination with no evidence of bleeding. On further review of her laboratory workup in the past several years, she was noted to have multiple episodes of low platelet counts. She was diagnosed with CTP after a recurrent pattern of fluctuations in her platelet count, with improvements sometimes without intervention. Unfortunately, most CTP patients are misdiagnosed as having primary immune thrombocytopenia (ITP), and CTP typically responds poorly to ITP therapy. This case underscores the need for further research and serves as a valuable reference to increase the awareness of clinicians about CTP.

The highs and lows of cyclic thrombocytopenia

Cyclic thrombocytopenia (CTP) is characterized by periodic platelet oscillation with substantial amplitude. Most CTP cases have a thrombocytopenic background and are often misdiagnosed as immune thrombocytopenia with erratically effective treatment choices. CTP also occurs during hydroxyurea treatment in patients with myeloproliferative diseases. While the aetiology of CTP remains uncertain, here we evaluate historical, theoretical and clinical findings to provide a framework for understanding CTP pathophysiology. CTP retains the intrinsic oscillatory factors defined by the homeostatic regulation of platelet count, presenting as reciprocal platelet/thrombopoietin oscillations and stable oscillation periodicity. Moreover, CTP patients possess pathogenic factors destabilizing the platelet homeostatic system thereby creating opportunities for external perturbations to initiate and sustain the exaggerated platelet oscillations. Beyond humoral and cell-mediated autoimmunity, we propose recently uncovered germline and somatic genetic variants, such as those of MPL, STAT3 or DNMT3A, as pathogenic factors in thrombocytopenia-related CTP. Likewise, the JAK2 V617F or BCR::ABL1 translocation that drives underlying myeloproliferative diseases may also play a pathogenic role in hydroxyurea-induced CTP, where hydroxyurea treatment can serve as both a trigger and a pathogenic factor of platelet oscillation. Elucidating the pathogenic landscape of CTP provides an opportunity for targeted therapeutic approaches in the future.

Cyclic Thrombocytopenia in the Setting of Intracranial Hemorrhage: A Diagnostic and Therapeutic Challenge

Cyclic thrombocytopenia (CTP) as the name suggests presents with cyclic episodes of thrombocytopenia and is frequently initially misdiagnosed as immune thrombocytopenia. Following a lack of sustained response or abnormally increased response to common treatments used for immune thrombocytopenia, a proper diagnosis of CTP can then be made. Prior reports have shown a subset of patients who respond to cyclosporin A. Here, we present a case of CTP that was initially at another facility presumed to have and treated for immune thrombocytopenic purpura. However, after multiple attempts to treat with steroids, intravenous immunoglobulin (IVIG), rituximab, and eltrombopag, episodes of severe thrombocytopenia followed by thrombocytosis continued. The patient ultimately developed intracerebral hemorrhage (ICH) in the setting of one of the episodes of severe thrombocytopenia and developed multiple subsequent complications from which the patient unfortunately did not recover. It was only after developing ICH that the patient had been evaluated at a center with hematology consultation capabilities, at which time after a detailed review of his case and pattern recognition the proper diagnosis of CTP was made with initiation of cyclosporine. This case was further complicated by need to maintain an adequate platelet threshold post-ventriculoperitoneal shunt placement which was necessary due to his ICH and was placed before diagnosis of CTP could be made. While CTP is a rare diagnosis, this case reinforces a greater need to properly diagnose and consider cyclosporine treatment for CTP, as it has been effective in some patients and may help to prevent patient morbidity and especially catastrophic bleeding complications.

Longitudinal study of 2 patients with cyclic thrombocytopenia, STAT3 and MPL mutations

Cyclic thrombocytopenia (CTP) is a rare disease of periodic platelet count oscillations. The pathogenesis of CTP remains elusive. To study the underlying pathophysiology and genetic and cellular associations with CTP, we applied systems biology approaches to 2 patients with stable platelet cycling and reciprocal thrombopoietin (TPO) cycling at multiple time points through 2 cycles. Blood transcriptome analysis revealed cycling of platelet-specific genes, which are in parallel with and precede platelet count oscillation, indicating that cyclical platelet production leads platelet count cycling in both patients. Additionally, neutrophil and erythrocyte-specific genes also showed fluctuations correlating with platelet count changes, consistent with TPO effects on hematopoietic progenitors. Moreover, we found novel genetic associations with CTP. One patient had a novel germline heterozygous loss-of-function (LOF) thrombopoietin receptor (MPL) c.1210G>A mutation, and both had pathogenic somatic gain-of-function (GOF) variants in signal transducer and activator of transcription 3 (STAT3). In addition, both patients had clonal T-cell populations that remained stable throughout platelet count cycles. These mutations and clonal T cells may potentially involve in the pathogenic baseline in these patients, rendering exaggerated persistent thrombopoiesis oscillations of their intrinsic rhythm upon homeostatic perturbations. This work provides new insights into the pathophysiology of CTP and possible therapies.

Cyclical Thrombocytopenia Synchronized With the Patient's Menstrual Cycle Treated With Danazol

Cyclical thrombocytopenia (CTP) is a very rare condition and often misdiagnosed as immune thrombocytopenia (ITP) due to similar features existing between the two. When evaluating a patient for the possible diagnosis of ITP, CTP must be high on the differential diagnosis. The main difference between the two conditions is that CTP is usually unresponsive to the treatment given to ITP and will ultimately display a cyclical nature with periods of low, normal and elevated platelets. As of date, there are only 70 cases in the literature. However, this number may be misrepresented due to the difficulty in diagnosis. The authors report a case of a 36-year-old woman who was misdiagnosed with ITP and underwent unnecessary treatment with corticosteroids, rituximab, intravenous immunoglobulins, and a splenectomy. A diagnosis of CTP was made after extensive review and the authors aim to bring awareness of this uncommon condition.

Cyclic Thrombocytopenia: A Rare Cause of Recurrent Thrombocytopenia

Cyclic thrombocytopenia (CTP) is a very rare hematological disorder that is characterized by periodic fluctuations in platelet counts. Diagnosis is generally delayed due to its similarity with immune thrombocytopenia (ITP). The pathophysiology is unknown and there are currently no guidelines for management. Many patients are usually treated for ITP initially prior to diagnosis. We describe a 67-year-old female with a history of multiple episodes of transient thrombocytopenia who presented to the hospital with another episode of thrombocytopenia. Her workup including HIV, hepatitis screening, vitamin B12, and folate was negative. She received a unit of platelet transfusion and was later observed in the hospital. Further review of her chart showed similar episodes in the past with spontaneous improvement. She was diagnosed with CTP. Her platelet count improved remarkably prior to discharge. In patients with recurrent fluctuation in their platelet count, CTP should be one of the differentials as this might prevent further unnecessary therapies.

Platelet variability index: a measure of platelet count fluctuations in patients with immune thrombocytopenia

Fluctuations in platelet count levels over time may help distinguish immune thrombocytopenia (ITP) from other causes of thrombocytopenia. We derived the platelet variability index (PVI) to capture both the fluctuations in platelet count measurements and the severity of the thrombocytopenia over time. Raw PVI values, ranging from negative (less severe thrombocytopenia and/or low fluctuations) to positive (more severe thrombocytopenia and/or high fluctuations) were converted to an ordinal PVI score, from 0 to 6. We evaluated the performance characteristics of the PVI score for consecutive adults with thrombocytopenia from the McMaster ITP Registry. We defined patients with definite ITP as those who achieved a platelet count response after treatment with intravenous immune globulin or high-dose corticosteroids and possible ITP as those who never received ITP treatment or did not respond to treatment. Of 841 patients with thrombocytopenia, 104 had definite ITP, 398 had possible ITP, and 339 had non-ITP thrombocytopenia. For patients with definite ITP, the median PVI score was 5 [interquartile range (IQR) 5, 6] for patients with possible ITP, the median PVI score was 3 (1, 5); and for patients with non-ITP thrombocytopenia, the median PVI score was 0 (0, 2). A high PVI score correlated with the diagnosis of definite ITP even when calculated at the patient's initial assessment, before any treatment had been administered. Platelet count fluctuations alone contributed to the specificity of the overall PVI score. The PVI score may help clinicians diagnose ITP among patients who present with thrombocytopenia for evaluation.