Vanoli Jennifer, Carrer Andrea, Martorana Roberto, Grassi Guido, Bombelli Michele
Divisione di Clinica Medica, Ospedale San Gerardo, Monza, Italy.
University of Milano-Bicocca, Milan, Italy.
J Med Case Rep. 2018 Oct 3;12(1):296. doi: 10.1186/s13256-018-1815-8.
Vitamin B deficiency-induced thrombotic microangiopathy, known as pseudothrombotic microangiopathy, is a rare condition which resembles the clinical features of thrombotic thrombocytopenic purpura but requires a markedly different treatment. Most cases of vitamin B deficiency have only mild hematological findings, but in approximately 10% of patients life-threatening conditions have been reported.
We report a case of a 46-year-old Moroccan man presenting with severe hemolytic anemia, thrombocytopenia, and renal failure in absence of macrocytosis, thus mimicking a genuine thrombotic thrombocytopenic purpura. Rapid improvement of renal function observed with only hydration and transfusions of packed red blood cells and the presence of pancytopenia suggested a bone marrow deficiency associated to a hemolytic component of unclear origin. Detection of low levels of vitamin B and rapid restitutio ad integrum with its replacement supported the diagnosis of pseudothrombotic thrombocytopenic purpura caused by vitamin B deficiency.
Diagnosis of pseudothrombotic thrombocytopenic purpura caused by vitamin B deficiency might be difficult. Awareness of clinicians toward this differential diagnosis might spare patients from unnecessary therapeutic plasma exchange that is burdened by morbidity and mortality.
维生素B缺乏引起的血栓性微血管病，即假性血栓性微血管病，是一种罕见疾病，其临床特征与血栓性血小板减少性紫癜相似，但治疗方法明显不同。大多数维生素B缺乏病例仅有轻微血液学表现，但据报道约10%的患者会出现危及生命的情况。
我们报告一例46岁摩洛哥男性病例，该患者出现严重溶血性贫血、血小板减少和肾衰竭，无大细胞性贫血，从而酷似真正的血栓性血小板减少性紫癜。仅通过补液和输注浓缩红细胞后肾功能迅速改善，且存在全血细胞减少，提示存在与不明原因溶血性成分相关的骨髓缺乏。检测到低水平维生素B并通过补充维生素B后迅速恢复正常，支持维生素B缺乏所致假性血栓性血小板减少性紫癜的诊断。
维生素B缺乏所致假性血栓性血小板减少性紫癜的诊断可能困难。临床医生了解这种鉴别诊断可能使患者避免不必要的治疗性血浆置换，而治疗性血浆置换存在发病率和死亡率问题。
