Abbreviations SLE: Systemic lupus erythematosus IVIG: Intravenous immunoglobulin TPO: Thrombopoietin
IVCY: Intravenous cyclophosphamide ANA: Antinuclear antibody eGFR: Estimated glomerular filtration rate HPF: High-power field LM: Light microscopy IF: Immunofluorescence EM: Electron microscopy ISN/RPS: International Society of Nephrology/Renal Pathology Society classification ITP: Idiopathic (immune) thrombocytopenic purpura PAM: Periodic acid-methenamine-silver.
: the primary regulator of platelet production," Blood, vol.
Wormann, "Clinical indications for thrombopoietin
and thrombopoietin-receptor agonists," Transfusion Medicine and Hemotherapy, vol.
 The treatment of CIT mainly depends on the disease severity with options being delay in reinitiation of chemotherapeutic regime or to stop the use of culprit drug, platelet transfusion if platelet count is below 20.000/[micro]l and recombinant thrombopoietin
Recently, the use of the thrombopoietin
receptor agonist eltrombopag has been approved in children older than one year with chronic ITP who have not responded to the administration of first-line drugs .
Although at the moment the reason for thrombocytopenia is not known, it is possible to hypothesize that the complex inflammatory response characterizing PIS might have determined an interference with the action of thrombopoietin
within the bone marrow.
(TPO) is a key regulator of megakaryopoiesis and megakaryocyte progenitor proliferation by promoting stem cell differentiation into megakaryocytes and their expansion, hence, boosting platelet production [9, 10].
Boukour et al., "miR-28 is a thrombopoietin
receptor targeting microRNA detected in a fraction of myeloproliferative neoplasm patient platelets," Blood, vol.
In addition, mutations in the thrombopoietin
receptor MPL , such as MPLW515L, or in the chaperone protein calreticulin (CALR) were identified in ET and MF, which converge on activation of JAK2 signaling [12-15].
Romiplostim, a TPO-ra that interacts with the extracellular domain of the thrombopoietin
receptor, has demonstrated rapid and sustained platelet increases in approximately 85% ofboth splenectomized and nonsplenectomized ITP patients, while reducing the use of concomitant medications, the requirement of splenectomy as salvage therapy, and, more importantly, the incidence of bleeding [13-17].
In 5-10% of patients the thrombopoietin
receptor (MPL) gene is impaired, while in 30-45% of patients no specific molecular marker had been described until the discovery of calreticulin (CALR).
(2) Liver cirrhosis can also cause thrombocytopenia because the liver is the main organ producing thrombopoietin