Severe vitamin B-12 deficiency in a child mimicking thrombotic thrombocytopenic purpura

Vitamin B12 deficiency misdiagnosed as TTP: What can we learn from it?

The case report by Dwyre et al. shows that vitamin B12 deficiency may be misdiagnosed as acute thrombotic thrombocytopenic purpura. Together with similar observations, this underlines that acquired vitamin B12 deficiency-besides the inherited disorder of intracellular cobalamin metabolism, cbl C disease-should be listed as a separate entity of the thrombotic microangiopathies. Commentary on: Dwyre et al. Microangiopathic thrombocytopenia caused by vitamin B12 deficiency responding to plasma exchange. Br J Haematol 2024; 205:1546-1550.

Congenital thrombotic thrombocytopenic purpura masquerading as vitamin B12 deficiency

INTRODUCTION

Congenital thrombotic thrombocytopenic purpura (CTTP), also called Upshaw-Schulman syndrome (USS), is a rare autosomal recessive disorder resulting from the deficiency of the ADAMTS13. CTTP is characterized by the formation of platelet-rich thrombi in small vessels of multiple organs, resulting in thrombocytopenia and microangiopathic hemolytic anemia, eventually leading to organ failure.

CASE REPORT

We present a case of an 11-month-old male infant with CTTP lacking classic features of the disease. Instead, his clinical picture portrayed vitamin B12 deficiency, leading to misdiagnosis and subsequent treatment delay.

CONCLUSION

This case led to the conclusion that congenital TTP should be suspected in case of vitamin B12 deficiency if the child does not respond to the vitamin B12 replacement therapy. We also emphasize that management for CTTP should be started at its earliest in case of increased clinical suspicion to avoid worse outcomes, especially in countries lacking rapid availability of enzyme assay.

Imerslund-Gräsbeck Syndrome presenting with microangiopathic hemolytic anemia in a child

Imerslund-Gräsbeck Syndrome is a rare autosomal recessive disorder characterized by proteinuria and selective malabsorption of cobalamin. Deficiency of cobalamin can lead to megaloblastic anemia, pancytopenia and even "pseudo"-thrombotic microangiopathy (TMA). Signs of mechanical hemolysis on peripheral blood smear, elevated lactate dehydrogenase and thrombocytopenia are common findings of TMA. We report a child presenting with TMA features with cobalamin deficiency. Because of her family history of vitamin B12 deficiency and proteinuria, the performed genetic analysis revealed that an Imerslund-Gräsbeck Syndrome with the detection of a homozygous mutation in AMN gene.

Vitamin B12 deficiency presenting as pseudo-thrombotic microangiopathy: a case report and literature review

Pseudo-thrombotic microangiopathy (pseudo-TMA) is a recognized, yet uncommon, clinical presentation of vitamin B12 deficiency. Patients with pseudo-TMA present with microangiopathic hemolytic anemia (MAHA), thrombocytopenia and schistocytes. They are often misdiagnosed as thrombotic thrombocytopenia purpura (TTP) and receive unnecessary therapy. Here, we report a case of a 60-year-old male who presented with thrombocytopenia and normocytic normochromic anemia. Anemia work-up was remarkable for severe B12 deficiency (<60 pg/mL) and a positive non-immune hemolysis panel. Peripheral smear was reviewed and showed anisocytes, poikilocytes, schistocytes and hypersegmented neutrophils. Vitamin B12 replacement (1000 mcg IM daily) was started, ADAMTS13 activity was sent and daily plasmapheresis was initiated. Over the next 3 days, the patient’s hemoglobin and platelets were stable and the hemolysis panel showed gradual improvement. On day 4, ADAMTS13 activity results came back normal at 61%. Accordingly, plasmapheresis was discontinued, parenteral B12 replacement was continued and that resulted in gradual improvement and eventually cessation of hemolysis and normalization of hemoglobin and platelets. In this patient, parietal cell autoantibodies were positive and so the diagnosis of pernicious anemia was made. Patients with severe vitamin B12 deficiency may present with features mimicking TTP such as MAHA, thrombocytopenia and schistocytosis. An early and accurate diagnosis of pseudo-TMA has a critical clinical impact with respect to administering the correct treatment with vitamin B12 replacement and avoiding, or shortening the duration of, unnecessary therapy with plasmapheresis.

Microangiopathic haemolytic anaemia with thrombocytopenia induced by vitamin B12 deficiency long term after gastrectomy

Microangiopathic haemolytic anaemia with thrombocytopenia, called pseudo-thrombotic microangiopathy (TMA), is a clinically important complication in patients with vitamin B12 deficiency. We herein present a case of an 80-year-old woman with pseudo-TMA after gastrectomy. She was initially suspected with thrombotic thrombocytopenic purpura based on rapid progression of anaemia with schistocytes and thrombocytopenia; however, her anaemia and thrombocytopenia were improved by vitamin B12 supplementation alone, with a single session of plasma exchange. Vitamin B12 deficiency was finally confirmed by low vitamin B12 levels from the patient's initial blood sample. In addition, normal ADAMTS13 activity was proven, lowering the likelihood of thrombotic thrombocytopenic purpura. Therefore, this patient was diagnosed with pseudo-TMA caused by vitamin B12 deficiency. Pseudo-TMA can occur in patients with vitamin B12 deficiency post-gastrectomy.

Cobalamin deficiency presenting with thrombotic microangiopathy (TMA) features: A systematic review

INTRODUCTION

Cobalamin deficiency may result in hematologic characteristics similar to thrombotic microangiopathy (TMA). To facilitate diagnosis, we reviewed reported cases of acquired cobalamin deficiency presenting with TMA features (c.def-TMA).

METHODS

A literature search identified reports of c.def-TMA. Deficiency was defined as B12 levels of <118 pmol/L. Corrected reticulocyte counts and reticulocyte production indexes were calculated. Clinical features were presented as proportion abnormal and results summarized as medians and interquartile ranges (IQR).

RESULTS

Patient level data was extracted from 41 identified cases. Median age (years) was 43 (30-55) with 21/41 (51%) being female. Cobalamin deficiency was noted in 35/40 (87.5%) but fold increases in MMA and HC were 30 and 6, respectively. The etiology was pernicious anemia in 28/41 (68%) cases. Anemia was both universal and severe, with hemoglobin levels of 55 g/L (4.7-6.6). Hypersegmented neutrophils were noted in 23/37 (62%), schistocytes in 29/38 (76%) and median LDH levels 3981 U/L (2004-5467). The RPI was <3.0% in all patients. Thrombocytopenia occurred in 33/41 (80.5%) with a median platelet count of 91 × 10⁹/L (42-112). Plasma infusion or exchange was initiated in 14/41 (34%) with associated complications in 2 cases.

CONCLUSION

Reticulocytopenia (RPI of <3.0%) was a universal finding that aids in differentiating c.def-TMA from other causes of hemolysis. C.def-TMA was associated with severe anemia, generally mild-moderate thrombocytopenia, and significant elevations in LDH.

Renal thrombotic microangiopathy and pulmonary arterial hypertension in a patient with late-onset cobalamin C deficiency

Cobalamin C (cblC) deficiency is the most commonly inherited inborn error of vitamin B12 metabolism. It is characterized by multisystem involvement with severe neurological, hematological, renal and cardiopulmonary manifestations. Disease is most commonly diagnosed early in the first decade of life. We report a case of a 20-year-old woman who developed severe pulmonary arterial hypertension while under nephrologic follow-up for chronic kidney disease. She had initially presented at 14 years of age with visual disturbance and acute renal failure and been diagnosed with thrombotic thrombocytopenic purpura on the basis of kidney biopsy findings of thrombotic microangiopathy and compatible ADAMTS13 (a disentegrin and metalloproteinase with a thrombospondin type 1 motif member 13). When cblC deficiency was eventually diagnosed, remarkable improvement in cardiopulmonary function was evident upon initiation of treatment. This case highlights the importance of a timely diagnosis and initiation of treatment for cblC deficiency. Clinical diagnosis may be challenged by asynchronous organ symptom presentation and by misleading laboratory tests, in this case: an initial low ADAMTS13. A simple test of plasma homocysteine level should be encouraged in cases of thrombotic microangiopathy and/or pulmonary artery hypertension.

Pernicious Anemia Associated Cobalamin Deficiency and Thrombotic Microangiopathy: Case Report and Review of the Literature

A 43-year-old Hispanic male without significant previous medical history was brought to emergency department for syncope following a blood draw to investigate a 40 lbs weight loss during the past 6 months associated with decreased appetite and progressive fatigue. The patient also reported a 1-month history of jaundice. On examination, he was hemodynamically stable and afebrile with pallor and diffuse jaundice but without skin rash or palpable purpura. Normal sensations and power in all extremities were evident on neurological exam. Presence of hemolytic anemia, schistocytosis, thrombocytopenia, and elevated lactate dehydrogenase (LDH) was suggestive of thrombotic thrombocytopenic purpura (TTP). However, presence of leukopenia, macrocytes, and an inadequate reticulocyte response to the degree of anemia served as initial clues to an alternative diagnosis. Two and one units of packed red blood cells were transfused on day 1 and day 3, respectively. In addition, one unit of platelets was transfused on day 2. Daily therapeutic plasma exchange (TPE) was initiated and continued until ADAMTS-13 result ruled out TTP. A low cobalamin (vitamin B12) level was evident at initial laboratory work-up and subsequent testing revealed positive intrinsic factor-blocking antibodies supporting a diagnosis of pernicious anemia with severe cobalamin deficiency. Hematological improvement was observed following vitamin B12 supplementation. The patient was discharged and markedly improved on day 9 with outpatient follow-up for cobalamin supplementation.

Differentiation of pernicious anemia from thrombotic thrombocytopenic purpura: The clinical value of subtle pathologic findings

BACKGROUND

Thrombotic thrombocytopenic purpura (TTP) is a microangiopathic hemolytic anemia that requires emergent treatment with plasma exchange and is one of the most important conditions for which apheresis service professionals are consulted. Careful interpretation of initial laboratory values and the peripheral blood smear is a critical first step to determining the need for plasma exchange because other conditions can show deceptively similar red cell morphology, and ADAMTS13 levels are often not rapidly available.

CASE REPORT

We report a case of a patient who was initially diagnosed with TTP and treated with plasma exchange based on preliminary laboratory data and a peripheral blood smear that contained bizarre microcytic red blood cells presumed to be schistocytes. The peripheral blood smear was later interpreted by the hematopathologist to be inconsistent with TTP, and further workup led to a diagnosis of severe vitamin B12 deficiency secondary to pernicious anemia.

RESULTS AND CONCLUSION

This case highlights the diagnostic complexity of thrombotic microangiopathies and the importance of a critical evaluation of the blood smear and presenting laboratory data when there is a concern for TTP.

Vitamin B12 Deficiency and Hemoglobin H Disease Early Misdiagnosed as Thrombotic Thrombocytopenic Purpura: A Series of Unfortunate Events

We herein would like to report an interesting case of a patient who presented with anemia and thrombocytopenia combined with high serum Lactic Dehydrogenase where Thrombotic Thrombocytopenic Purpura was originally considered. As indicated a central venous catheter was inserted in his subclavian vein which led to mediastinal hematoma and finally intubation and Intensive Care Unit (ICU) hospitalization. After further examination patient was finally diagnosed with B12 deficiency in a setting of H hemoglobinopathy. There have been previous reports where pernicious anemia was originally diagnosed and treated as Thrombotic Thrombocytopenic Purpura but there has been none to our knowledge that was implicated with hemothorax and ICU hospitalization or correlated with thalassemia and we discuss the significance of accurate diagnosis in order to avoid adverse reactions and therapy implications.

Neglect-induced pseudo-thrombotic thrombocytopenic purpura due to vitamin B12 deficiency

Although thrombotic thrombocytopenic purpura (TTP) is rare, early diagnosis and treatment are important for decreasing the mortality rate. Acquired vitamin B12 deficiency is frequently overlooked because of its rarity in developed countries, particularly in children and adolescents. The hematological changes in vitamin B12 deficiency present as megaloblastic anemia, increased lactate dehydrogenase, vasoconstriction, increased platelet aggregation, and abnormal activation of the coagulation followed by microangiopathy as well as neutropenia and thrombocytopenia. We report herein the case of a 15-year-old girl who had been neglected, which might have caused pseudo-TTP through malnutrition, particularly vitamin B12 deficiency. When we encounter cases of TTP in children, clinicians must be aware of the possibility of malnutrition, particularly with vitamin B12 deficiency, even in developed countries, and investigate the cause of malnutrition including neglect.