Rationale:Dengue fever is capable of inciting the formation of transient polyclonal antibodies directed at red blood cell antigens,resulting in complement-mediated hemolysis,leading to intravascular hemolysis and hemoglobinuria.Patient’s concern:A 12-year-old male patient who recovered from dengue fever a week ago had red blood cell agglutination,spherocytes,and engulfment of red blood cells(erythrophagocytosis)by monocytes and neutrophils on routine hematological peripheral blood smear.The unexpected blood smear results prompted the lab physicians to investigate autoimmune hemolytic anemia,which revealed a monospecific positive direct antiglobulin test for complement(C3d,C3b)and the presence of Donath-Landsteiner antibody.Diagnosis:Paroxysmal cold hemoglobinuria(PCH),secondary to dengue fever.Interventions:Oxygen supplements,antibiotics,intravenous immunoglobulins,steroid therapy,and packed cell transfusions were administered.Outcomes:The patient’s condition was improved following the therapy.Lessons:Post-dengue PCH is a rare complication that requires a thorough peripheral smear examination for erythrophagocytosis,as advanced hematology analyzers fail to detect such findings.
Momin Majed Abdul BasitAluri AnamikaSyed Arfa AshrafunnisaRahul Dev Singh Rathore
Paroxysmal kinesigenic dyskinesia(PKD),the most common type of paroxysmal movement disorder,is characterized by sudden and brief attacks of choreoathetosis or dystonia triggered by sudden voluntary movements.PKD is mainly caused by mutations in the PRRT2 or TMEM151A gene.The exact pathophysiological mechanisms of PKD remain unclear,although the function of PRRT2 protein has been well characterized in the last decade.Based on abnormal ion channels and disturbed synaptic transmission in the absence of PRRT2,PKD may be channelopathy or synaptopathy,or both.In addition,the cerebellum is regarded as the key pathogenic area.Spreading depolarization in the cerebellum is tightly associated with dyskinetic episodes.Whereas,in PKD,other than the cerebellum,the role of the cerebrum including the cortex and thalamus needs to be further investigated.
