Hemolysis and schistocytosis in the emergency department: consider pseudothrombotic microangiopathy related to vitamin B12 deficiency

Vitamin B12 Deficiency Mimicking Thrombotic Thrombocytopenic Purpura: A Case Report and Review of Literature

Vitamin B12 (cyanocobalamin) deficiency can lead to ineffective erythropoiesis, intramedullary hemolysis, and, in severe cases, neurologic deficits. Some of those findings are also features of thrombotic microangiopathies, specifically thrombotic thrombocytopenic purpura (TTP), and the distinction between both entities could sometimes be challenging. While the treatment of the former consists of enteral or parenteral repletion, the treatment of TTP is more complex and time-sensitive. For that reason, refining diagnostic strategies is crucial to avoid misdiagnosis and unnecessary interventions. Here is an example of a potential life-threatening hemolysis caused by vitamin B12 deficiency with acute onset neurologic symptoms, which resolved with B12 repletion.

Adult Vitamin B12 Deficiency-Associated Pseudo-Thrombotic Microangiopathy: A Systematic Review of Case Reports

Cobalamin-deficient thrombotic microangiopathy or vitamin B12 deficiency presenting as pseudo-thrombotic microangiopathy is a rare disorder that can be misdiagnosed as thrombotic thrombocytopenic purpura. Patients with this condition are at risk of receiving unnecessary plasmapheresis with a potential delay in appropriate therapy with vitamin B12 supplementation. There are no established diagnostic criteria for this condition in clinical practice. We performed a systematic review of case reports published between January 2018 and January 2023 to analyze the clinical characteristics, risk factors, and patterns of laboratory markers to improve the diagnostic criteria for this condition.

Vitamin B12 Deficiency Disguised As Hemolytic Anemia: A Case Presentation

This case report describes an 18-month-old male presenting with hemolytic anemia and lethargy, who was ultimately diagnosed with severe vitamin B12 deficiency. The child exhibited global developmental delays, including a lack of speech and walking skills. Initially suspected as intravascular hemolytic anemia, the normal reticulocyte count led to further investigation, which revealed low cobalamin (vitamin B12) levels. The patient received vitamin B12 injections, resulting in normalized cobalamin levels. Additional evaluations ruled out metabolic disorders and other etiologies for his anemia. Follow-up laboratory testing showed improved hemoglobin levels, and the patient was discharged with plans for close monitoring. The case emphasizes the importance of considering vitamin B12 deficiency in children, particularly those with developmental delays and anemia. Early diagnosis and treatment are crucial for preventing long-term neurological consequences associated with severe and prolonged cobalamin deficiency. Healthcare professionals should be aware of the impact of nutrient deficiencies on growth, development, and brain maturation in pediatric populations.

Molecular Mimicry: An Uncommon Occurrence of Vitamin B12 Deficiency Imitating Thrombotic Thrombocytopenic Purpura in an African American Male

Thrombotic thrombocytopenic purpura (TTP) and vitamin B12 deficiency can share similar symptoms but require different treatment approaches. TTP is a blood disorder with a high mortality rate requiring immediate plasmapheresis treatment. On the other hand, vitamin B12 deficiency usually presents with anemia, low platelet counts, jaundice, and signs of disrupted red blood cell breakdown, resembling a condition called microangiopathic hemolytic anemia. Vitamin B12 deficiency can sometimes lead to or mimic pseudo-thrombotic microangiopathy (pseudo-TMA), a rare occurrence. Pseudo-TMA manifests as microangiopathic hemolytic anemia and thrombocytopenia and is characterized by schistocytes in a peripheral blood smear. Differentiating TTP cases from pseudo-TMA cases is essential and should be done promptly. The etiology, treatments, and prognosis of these two conditions differ and can be fatal if not identified and managed. We present a case that emphasizes the need for familiarity with TTP-like conditions, the use of ADAMTS13 as a diagnostic tool, prompt and accurate treatment decision-making, the complexities of therapeutic plasma exchange, and the importance of excluding an enzyme inhibitor or mutator as the cause of TTP or TTP-like cases. Lack of knowledge can lead to erroneous diagnoses, resulting in unnecessary treatments or delayed life-saving interventions.

Pseudo-thrombotic microangiopathy due to folate deficiency

Classically, deficiencies of vitamin B12 and folate are associated with megaloblastic anaemia. Additionally, vitamin B12 is able to cause a haemolytic anaemia in the form of pseudo-thrombotic microangiopathy (pseudo-TMA). Here, we present a case of a middle-aged woman with a history of Roux-en-Y gastric bypass who presented with dyspnoea and fatigue and was found to have thrombocytopenia and a non-immune haemolytic anaemia. Work-up for haemolytic uraemic syndrome, thrombotic thrombocytopenic purpura, paroxysmal nocturnal haemoglobinuria, infection, malignancy and autoimmune conditions was unremarkable. Her haemolytic anaemia and thrombocytopenia resolved with folate replenishment. She was diagnosed as likely having pseudo-TMA secondary to folate deficiency.

Vitamin B12 deficiency presenting with a pancytopenia in pregnancy

Vitamin B12 deficiency is a significant public health problem globally. Although it is a well-known cause of macrocytic anaemia and in advanced cases, pancytopenia, there remains a relative paucity of cases reported in pregnancy. It is associated with an increased risk of pregnancy complications and adverse birth outcomes such as neural tube defects, preterm birth, low birth weight, neurological sequelae and intrauterine death. It has a predilection for individuals aged >60 years. It has been implicated in a spectrum of neuropsychiatric disorders and it may also exert indirect cardiovascular effects. Severe vitamin B12 deficiency may present with haematological abnormalities that mimic thrombotic microangiopathy such as HELLP syndrome (haemolysis, elevated liver enzymes and low platelets) or it may present as pseudothrombotic microangiopathy (Moschcowitz syndrome) characterised by anaemia, thrombocytopenia and schistocytosis. It can also closely mimic thrombotic thrombocytopenia purpura, hence posing a diagnostic challenge to the unwary physician. Serological measurement of vitamin B12 levels confirms the diagnosis. Oral supplementation with vitamin B12 remains a safe and effective treatment. The authors describe the case of a multiparous woman in her late 20s presenting with a plethora of non-specific symptoms at 29+5 weeks' gestation. Her haemoglobin was 45 g/L, platelets 32×109/L, vitamin B12 <150 ng/L and serum folate <2 µg/L. She was not a vegetarian, but her diet lacked nutrition. Following parenteral B12 supplementation, her haematological parameters improved. The pregnancy was carried to term. Due to the plethora of non-specific symptoms, the diagnosis can be challenging to establish. Adverse maternal or fetal outcomes may occur. Folic acid supplementation may mask an occult vitamin B12 deficiency and further exacerbate or initiate neurological disease.

A Rare Presentation of Pernicious Anemia Manifesting as Disseminated Intravascular Coagulation

Pernicious anemia is an autoimmune disorder that is characterized by the presence of autoantibodies to intrinsic factor and parietal cells which results in the inability to absorb vitamin B12. It is the most common manifestation of vitamin B12 deficiency and accounts for 20-50% of cases. Disseminated intravascular coagulation (DIC) is a clinical condition that is a complication of another process which causes the activation of coagulation. A 63-year-old female with a history of hypothyroidism presented with a 1-month history of worsening fatigue, intermittent epigastric pain, nausea, vomiting, and diarrhea. Initial laboratory findings showed severe anemia and macrocytosis with a hemoglobin of 4.3 g/dL and a mean corpuscular volume (MCV) of 138 fL. There was also a significant elevation of the D-dimer, lactate dehydrogenase (LDH), and creatinine. She received three units of packed red blood cells (pRBCs) and fluid resuscitation. A vitamin B12 level was obtained which revealed a severe vitamin B12 deficiency (< 150 pg/mL). Additional workup showed seropositivity for anti-parietal cell antibodies and intrinsic factor blocking antibodies, and an esophagogastroduodenoscopy (EGD) biopsy yielded histologic findings consistent with autoimmune gastritis. She was treated acutely with daily intramuscular B12 injections with improvement in hematologic derangements and symptomatology. Arrested erythropoiesis can lead to apoptosis and the high proliferation of immature erythroblasts results in cells that are more susceptible to impaired deoxyribonucleic acid (DNA) synthesis and results in denatured DNA. Pernicious anemia manifesting as DIC has yet to be described in the literature. Here we describe an interesting case of pernicious anemia manifesting as early DIC resulting from arrest of erythropoiesis evidenced by the international society on thrombosis and hemostasis score of 5, diagnostic for DIC. Early recognition and treatment of this reversible etiology of DIC is essential to the improvement of patient outcomes.

Approach to Pancytopenia in a Deployed Service Member

BACKGROUND

Pancytopenia is a result of increased destruction or decreased production of bone marrow cells and has a broad differential. Pernicious anemia commonly presents as a macrocytic anemia and is typically autoimmune in nature and the result of vitamin B₁₂ deficiency. Pancytopenia is a rare presentation of this disorder especially in the setting of hemolysis. Testing in the deployed setting may be limited and/or challenging.

CASE PRESENTATION

A 24-year-old female patient with a history of Hashimoto thyroiditis presented during an overseas deployment with a witnessed syncopal episode and was found to be pancytopenic with a mild transaminitis and laboratory tests demonstrating hemolysis. Though initially she was hypotensive, tachycardic, and febrile, her vitals improved after multiple transfusions, but she had persistent cytopenia with transfusion dependence, concerning for aplastic anemia or acute leukemia.

CONCLUSIONS

Testing for B₁₂ deficiency is crucial in symptomatic, patients with pancytopenic to either diagnose or exclude pernicious anemia and conserve resources by preventing costly workup and transfer/escalation of medical care, especially in the deployed setting. A predeployment screening in those with history of autoimmune disorders may be warranted.

Macrocytic Anaemia: Not Always a Straightforward Diagnosis

Macrocytosis is defined as a mean corpuscular volume greater than 100 femtolitres (fL). There are several causes for macrocytic anaemia, and they can be divided into megaloblastic or non-megaloblastic anaemia. Vitamin B12 deficiency is one of the most common causes of megaloblastic anaemia.

The cause of vitamin B12 deficiency must be evaluated including the presence of pernicious anaemia as it could alter the treatment and follow-up.

Pernicious anaemia can be associated with other autoimmune diseases constituting polyglandular syndromes.

Metabolism-mediated thrombotic microangiopathy and B12

Thrombotic microangiopathies (TMAs) are a group of life-threatening conditions requiring urgent management and characterized by a clinical triad of microangiopathic hemolytic anemia, thrombocytopenia, and ischemic tissue injury. Severe vitamin B12 (Cobalamin-Cbl) deficiency or defective cobalamin metabolism, particularly defects in intracellular B12 metabolism, may lead to a TMA-like picture. The latter has been termed metabolism-mediated TMA (MM-TMA). This confusing picture is mediated partly by ineffective erythropoiesis with significant red cell fragmentation resulting in a hemolytic pattern, coupled with reduced platelet production and endothelial injury with organ damage resulting from accumulated toxic byproducts of B12 dysmetabolism. However, unlike in classic thrombotic thrombocytopenic purpura, where therapeutic plasma exchange has to be initiated promptly, cases of MM-TMA can be treated, if diagnosed properly, with adequate B12 replacement.

How I investigate acquired megaloblastic anemia

In this review of megaloblastic anemia (MA), an overview of vitamin B₁₂ and folate body requirements, biochemical pathways, and laboratory testing strategies will be provided. However, the focus of this review is the classic and unique features of MA in blood and bone marrow. Acquired MA is a benign disorder for many, but can be detrimental for some. The clinical presentation can vary considerably, and the spectrum of symptoms and signs is diverse and quite broad. Prompt recognition and therapy are critical to prevent potential irreversible damage and clinical sequelae, especially in patients with vitamin B₁₂ deficiency. A delay in diagnosis of vitamin B₁₂ deficiency can result in significant neurologic sequelae that may not fully resolve with treatment, including in neonates and young infants. The blood and bone marrow features in MA can closely mimic thrombocytopenic purpura, myelodysplasia, and other myeloid neoplasms. Both pancytopenia and normal MCV at presentation are common in MA and raise unique challenges for the diagnostician. Partially treated MA is also a significant diagnostic "trap". MA is highly responsive to treatment, and patients tend to improve rapidly upon treatment initiation. However, the broad range of clinical and hematologic features makes the rapid, successful diagnosis of MA a unique challenge for the hematopathologist. Even in the era of state-of-the-art laboratory testing, a high suspicion is required.

Life-Threatening Microangiopathy or Vitamin Deficiency: A Case Report of the Clinical Manifestations of Pseudo-Thrombotic Microangiopathic Anemia

Hemolytic anemia with thrombocytopenia and organ damage raises suspicion for thrombotic microangiopathy (TMA), a pathology that results in thrombosis within the small vessels secondary to endothelial injury. While usually attributed to atypical hemolytic uremic syndrome (aHUS) or thrombotic thrombocytopenic purpura (TTP), an increasingly recognized and treatable entity is pseudo-thrombotic microangiopathic anemia (pseudo-TMA) secondary to severe vitamin B-12 deficiency.

While TMA often requires expensive diagnostic testing and can lead to invasive treatment options such as plasma exchange, immunosuppression, and/or complement cascade blocking, pseudo-TMA requires only vitamin supplementation. Therefore, the prompt and accurate diagnosis of this entity is important for the clinician to recognize in order to avoid unnecessary health costs and institute appropriate treatment.

We present the case of a 51-year-old male without any past medical history, who presented with generalized weakness, dyspnea on exertion, and decreased exercise tolerance for several months and was found to have severe microangiopathic anemia with work-up concerning for TTP. After stabilization, he was found to have severe B-12 deficiency secondary to newly diagnosed pernicious anemia and was treated with subcutaneous B-12 injections with improvement in clinical symptoms and laboratory parameters. This presentation highlights the need for prompt diagnosis and high clinical suspicion for vitamin deficiencies as a source of pseudo-microangiopathy.

Pseudothrombotic Microangiopathy as a Rare Presentation of Cobalamin Deficiency

The hematological manifestations of cobalamin (vitamin B12) deficiency may range from asymptomatic to life-threatening forms. Pseudothrombotic microangiopathy is a rare but severe presentation, characterized by the presence of hemolysis and schistocytosis, that is completely reversible after vitamin supplementation.

We present a challenging diagnostic approach of a 55-year-old man who presented with high hemolytic markers, pancytopenia, and schistocytes on the peripheral smear due to acquired cobalamin deficiency. Subsequent testing revealed positive anti-intrinsic factor and anti-parietal cell antibodies consistent with pernicious anemia. Cobalamin replacement led to the resolution of microangiopathic hemolysis and clinical improvement, thereby confirming the diagnosis.

This case highlights the importance of early recognition of this syndrome, which is often misdiagnosed as true microangiopathic hemolytic anemia, confounding appropriate management.

Severe Vitamin B12 Deficiency Mimicking Microangiopathic Hemolytic Anemia

Most individuals with vitamin B12 deficiency present with anemia, fatigue, and neurologic disturbances such as paresthesia and loss of sensory function if chronic. However, in severe states, it may manifest as hemolytic anemia, thrombocytopenia, schistocytosis, elevated lactate dehydrogenase, and low reticulocyte production. This phenomenon is known as pseudo-thrombotic microangiopathy (TMA), and is most commonly due to pernicious anemia. The overlap in clinical presentation with primary TMA creates a challenge in the diagnosis and management of pseudo-TMA. Primary TMA, particularly thrombotic thrombocytopenic purpura, is emergently managed with plasma exchange and may require admission to an intensive care unit due to high risk of mortality. In contrast, pseudo-TMA does not respond to plasma exchange and instead is treated with vitamin B12 supplementation. Patients with this atypical presentation of B12 deficiency may receive unnecessary, costly, and potentially harmful therapy. We present the case of a patient with pseudo-TMA in the setting of pernicious anemia.

2021 update of the 2012 ICSH Recommendations for identification, diagnostic value, and quantitation of schistocytes: Impact and revisions

In 2012, the International Council for Standardization in Hematology (ICSH) published recommendations for the identification, quantitation, and diagnostic value of schistocytes. In the present review, the impact of these recommendations is evaluated. This work is based on citations in peer-reviewed papers published since 2012. The first 2012 ICSH Recommendations have also been revised to incorporate newly published data in the literature and current best laboratory practice. Recommended reference ranges have been proposed for healthy adults and full-term neonates of 1% or less schistocytes. More than 1% of morphologically identified schistocytes on the blood film are considered suspicious for thrombotic microangiopathy. For preterm infants, a normal level of 5% or less is recommended. The fragment red cell count (FRC) generated by some automated hematological analyzers provides a valuable screening tool for the presence of schistocytes. Specifically, the absence of FRCs can be used as a valuable parameter to exclude the presence of schistocytes on the blood film. The validity and usefulness of microscope schistocytes and automated FRCs, respectively, are discussed in the context of the laboratory diagnostic tests used for thrombotic microangiopathies.

The doctor who stared at schistocytes: an intriguing case of suspected thrombotic microangiopathic anemia

A 33-year-old man with type 1 diabetes mellitus was admitted to the Internal Medicine Unit due to subacute onset of exertional dyspnea, with evidence at initial blood exams of severe macrocytic anemia with thrombocytopenia, biohumoral signs of hemolysis and 5 schistocytes per magnified field on the blood smear. A thrombotic microangiopathy (TMA) was suspected and plasma exchange (PEX) was started soon, since the risk of a life threatening condition. On the second day, after the results of A Disintegrin And Metalloproteinase with ThromboSpondin-1 motif, member 13 (ADAMTS-13) and reticulocytes were available, a critical reappraisal of the clinical scenario was done. B12 vitamin deficiency was evident after completing the diagnostic work-up. Finally, a diagnosis of "pseudo TMA vitamin B12 deficiency-related" was done. This is an intriguing and rare manifestation of cobalamin deficiency, given the very uncommon occurrence of schistocytes in this condition. "Pseudo TMA vitamin B12 deficiency-related" should be kept in mind when facing the differential diagnosis of microangiopathic anemia in the presence of a low proliferative index.

Vitamin B12 Deficiency Presenting With Microangiopathic Hemolytic Anemia

Vitamin B12 has essential roles in DNA synthesis, red blood cell development, and neurologic functions. Vitamin B12 deficiency is relatively common, particularly in people aged over 60 years. Among hematological disturbances, microangiopathic hemolytic anemia with thrombocytopenia or so-called pseudo-thrombotic microangiopathy (pseudo-TMA) is a particularly rare but significant clinical complication in patients with vitamin B12 deficiency. We herein describe a case of an elderly patient with pseudo-TMA whose lack of vitamin B12 was misdiagnosed as thrombotic thrombocytopenic purpura (TTP). The patient was admitted as a case of pancytopenia with a hemolytic picture. The initial impression was TTP versus acute promyelocytic leukemia M3. After examination of laboratory tests and bone marrow examination, we deduced that the patient had a B12 deficiency. The condition of the patient improved with B12 replacement. This report should remind physicians to widen their differential diagnoses when patients present with microangiopathic hemolysis or in patients who are not responsive to standard treatments for TTP.

Et Tu, B12? Cobalamin Deficiency Masquerading As Pseudo-Thrombotic Microangiopathy

Vitamin B12 deficiency is classically associated with megaloblastic anemia. Possible cobalamin deficiency is not investigated once hemolysis is seen. Around 2.5% of cases can present as pseudo-thrombotic microangiopathy (TMA). A swift identification of this means the difference between an easy solution and a protracted one for the patient. A 74-year-old man with no past medical history presented with exertional dyspnea, fatigue, and increasing anorexia over two weeks. Physical examination including a neurological examination was normal. Laboratory tests revealed pancytopenia, unconjugated hyperbilirubinemia, elevated LDH (lactate dehydrogenase), low haptoglobin, and fragmented red blood cells (RBCs) on the peripheral smear, but normal FDP (fibrinogen degradation product) and fibrinogen. The absolute reticulocyte count was reduced as opposed to the expected elevation. Vitamin B12 levels were undetectable, and severe cobalamin deficiency from pernicious anemia was found to be the paramount etiology. Cobalamin deficiency causing pseudo-TMA baffles most physicians. Advanced pernicious anemia is thought to cause intramedullary hemolysis, resulting in peripheral pancytopenia. The fragile RBCs are easily sheared, producing schistocytosis without platelet microthrombi. In contrast to hemolytic anemias, reticulocyte count is low given the unavailability of B12 for erythropoiesis. Reticulocytopenia is a universal finding in cases of pseudo-TMA. Around 38.8% of cases with pseudo-TMA are misdiagnosed as thrombotic thrombocytopenic purpura and treated with plasma product therapy. Keeping an eye out for reticulocytopenia in cases of hemolysis could mean a world of difference for the patient.

Pancytopenia and TTP-like picture secondary to pernicious anaemia

A 21-year-old man presented to the emergency department with generalised weakness, weight loss and decreased appetite for few weeks. He had evidence of severe pancytopenia and haemolysis. His peripheral smear with many schistocytes was suspicious for thrombotic thrombocytopenic purpura (TTP). He was supported with blood transfusions and daily plasmapheresis. His platelet counts worsened despite 4 days of therapy. Bone marrow biopsy was significant for hypercellular bone marrow with megaloblastic changes. Further workup revealed normal ADAMTS13 level, low vitamin B12, positive intrinsic factor antibodies and high methylmalonic acid. Diagnosis of pernicious anaemia was established and he was started on daily treatment with intramuscular vitamin B12which subsequently improved his symptoms and haematological parameters. This report highlights the importance of checking vitamin B12level in patients presenting with pancytopenia and TTP-like picture before making a diagnosis of TTP.

Pernicious Anemia Presenting With Pseudo Thrombotic Microangiopathy and Falsely Elevated B 12 Levels

Pseudo thrombotic microangiopathy is a distinct clinical entity that is seen in patients with B12 deficiency. We describe a patient who presented with microangiopathic hemolytic anemia, thrombocytopenia, altered mentation and renal insufficiency. Thrombotic thrombocytopenic purpura was a major concern; however the peripheral blood smear showed hypersegmented neutrophils and the altered mental status as well as renal dysfunction improved with red cell transfusions. It was concluded that her clinical picture was more consistent with ineffective erythropoiesis, which can mimic thrombotic thrombocytopenic purpura (TTP). She was ultimately diagnosed with pernicious anemia based on positive intrinsic factor antibody, elevated methylmalonic acid, and homocysteine levels. Her B12 levels were falsely elevated which confounded the diagnosis. Distinguishing between these two conditions is imperative to avoid unwarranted plasmapheresis.

Vitamin B12 deficiency and metabolism-mediated thrombotic microangiopathy (MM-TMA)

Thrombotic microangiopathies (TMA) are characterized by microangiopathic hemolytic anemia, thrombocytopenia and organ damage resulting from mechanical factors, accumulation of the ultra-large von Willebrand factor multimers or complement-mediated abnormalities. Severe acquired vitamin B12 (Cobalamin - Cbl) deficiency or congenital defective Cbl metabolism could lead to a picture that mimics TMA. The later has been termed metabolism-mediated TMA (MM- TMA). This confusing picture is mediated partly by the large red cell fragmentation coupled with reduced platelet production in the absence of vitamin B12 and partly by the accumulated byproducts and metabolites that induce endothelial injury and hence organ damage. Expensive and complicated treatment for TMA is often initiated on an empiric basis, pending the results of confirmatory tests. In contrast, vitamin B12 Pseudo-TMA and MM-TMA could be treated with proper vitamin B12 supplementation. It is therefore important to identify these disorders promptly. The recent availability of a validated scoring system such as the PLASMIC score uses simple clinical and laboratory parameters. As it incorporates the mean corpuscular volume in its laboratory parameters, this helps in the identification of pseudo and MM-TMA. Perhaps some minor modification of this scoring system by changing the parameters of hemolysis to include reticulocytosis and rather than and/or other hemolytic parameters could even help refine this identification.

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.

[Kidney disease in cobalamin C deficiency]

Cobalamin C deficiency (cblC) is the most common inborn error of vitamin B₁₂ metabolism. This autosomal recessive disease is due to mutations in MMACHC gene, encoding a cyanocobalamin decyanase. It leads to hyperhomocysteinemia associated with hypomethioninemia and methylmalonic aciduria. Two distinct phenotypes have been described : early-onset forms occur before the age of one year and are characterized by a severe multisystem disease associating failure to thrive to neurological and ophthalmological manifestations. They are opposed to late-onset forms, less severe and heterogeneous. CblC deficiency-associated kidney lesions remain poorly defined. Thirty-eight cases have been described. Age at initial presentation varied from a few days to 28 years. Most of the patients presented renal thrombotic microangiopathy (TMA) associated with acute renal failure, and 21 patients presented typical lesions of renal thrombotic microangiopathy on kidney biopsy. Prognosis was poor, leading to death in the absence of treatment, and related to the severity of renal lesions in the early-onset forms. Late-onset disease had better prognosis and most of patients were weaned off dialysis after treatment initiation. We suggest that all the patients with renal TMA be screened for cobalamin metabolism disorder, regardless of age and even in the absence of neurological symptoms, to rapidly initiate the appropriate treatment.

Severe Vitamin B12 Deficiency in Pregnancy Mimicking HELLP Syndrome

Severe vitamin B12 deficiency may present with hematologic abnormalities that mimic thrombotic microangiopathy disorders such as hemolysis, elevated liver enzymes, and low platelet count (HELLP) syndrome. We report a patient diagnosed with severe vitamin B12 deficiency, following termination of pregnancy for suspected preeclampsia and HELLP syndrome at 21 weeks' gestation. When hemolysis and thrombocytopenia persisted after delivery, testing was performed to rule out other etiologies of thrombotic microangiopathy, including atypical hemolytic uremic syndrome, thrombotic thrombocytopenic purpura, and vitamin B12 deficiency. This work-up revealed undetectable vitamin B12 levels and presence of intrinsic factor antibodies, consistent with pernicious anemia. Parenteral B12 supplementation was initiated, with subsequent improvement in hematologic parameters. Our case emphasizes the importance of screening for B12 deficiency in pregnancy, especially in at-risk women with unexplained anemia or thrombocytopenia. Moreover, providers should consider B12 deficiency and pernicious anemia in the differential diagnosis of pregnancy-associated thrombotic microangiopathy.

A Rare Cause of Thrombotic Thrombocytopenia Purpura- (TTP-) Like Syndrome, Vitamin B12 Deficiency: Interpretation of Significant Pathological Findings

Thrombotic thrombocytopenia purpura (TTP) is a hematological emergency that requires rapid assessment followed by prompt initiation of therapy due to high mortality associated with delayed treatment. TTP has many causes including heritable syndromes, ADAMTS13 deficiency, and drugs-related etiologies. Profound vitamin B12 deficiency can, in rare cases, mimic TTP in presentation, and since plasmapheresis can be of limited benefit, prompt diagnosis is necessary for accurate treatment with B12. Therefore, careful analysis of all clinical signs, symptoms, and labs must be assessed. We report a patient who presented with a diagnosis of TTP, and repeat assessment confirmed a diagnosis of sever vitamin B12 (B12) deficiency with pancytopenia who was appropriately treated with B12.

Relationship between cobalamin and folate deficiencies and anemia in dogs

Background

Megaloblastic, nonregenerative anemia is a well‐known consequence of cobalamin or folate deficiencies in humans but is not recognized in hypocobalaminemic or hypofolatemic dogs. Establishment of relationships between hypocobalaminemia or hypofolatemia and hematologic disease would encourage vitamin B testing, and potentially supplementation, in anemic dogs.

Objectives

To determine the prevalence of anemia in hypocobalaminemic or hypofolatemic dogs and to report the prevalence of hypocobalaminemia and hypofolatemia and nonregenerative anemia, macrocytosis, and anisocytosis in anemic dogs.

Animals

One hundred and fourteen client‐owned dogs with known serum cobalamin and folate concentrations and CBCs and 42 client‐owned anemic dogs.

Methods

Retrospective comparison of anemia prevalence in hypocobalaminemic or hypofolatemic and normocobalaminemic or normofolatemic dogs was performed. Prospective measurement of erythrocyte variables and cobalamin and folate concentrations in anemic dogs was carried out; relationships among hypocobalaminemia and regenerative status, mean corpuscular volume, and red cell distribution width were evaluated.

Results

Significant differences in prevalence of anemia between hypocobalaminemic (36%) and normocobalaminemic dogs (26%; P = .23) or between hypofolatemic (31%) and normofolatemic dogs (30%; P = .99) were not detected. Between hypocobalaminemic and normocobalaminemic dogs, no significant differences in prevalence of nonregenerative anemia (69% vs 63%; P = .65), macrocytosis (17% vs 0%; P = .53), or anisocytosis (28% vs 0%; P = .14) were detected. Anemic dogs had high prevalence of vitamin B deficiencies (nonregenerative: 64% hypocobalaminemic, 18% hypofolatemic; regenerative: 57% hypocobalaminemic, 21% hypofolatemic).

Conclusions and Clinical Importance

The association between cobalamin and folate deficiencies and macrocytic, nonregenerative anemia established in humans is not routinely present in dogs.

Vitamin B12 deficiency-induced pseudothrombotic microangiopathy without macrocytosis presenting with acute renal failure: a case report

BACKGROUND

Vitamin B₁₂ 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 B₁₂ deficiency have only mild hematological findings, but in approximately 10% of patients life-threatening conditions have been reported.

CASE PRESENTATION

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 B₁₂ and rapid restitutio ad integrum with its replacement supported the diagnosis of pseudothrombotic thrombocytopenic purpura caused by vitamin B₁₂ deficiency.

CONCLUSIONS

Diagnosis of pseudothrombotic thrombocytopenic purpura caused by vitamin B₁₂ 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.

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.

Platelet activation markers in children with congenital heart disease associated with pulmonary arterial hypertension

BACKGROUND

Mean platelet volume (MPV), platecrit, and platelet distribution width (PDW) are markers of platelet activation. Previous studies have found that platelet activation occurs in patients with pulmonary arterial hypertension. Platelet indices including MPV, PDW, and platecrit have not been studied in children with congenital heart disease associated pulmonary arterial hypertension (APAH-CHD) who survived and those who died.

OBJECTIVE

The objective of this study to investigate the value of platelet indices with clinical and hemodynamic indicators predicting the disease severity and survival in children with APAH-CHD.

METHODS

This was a nested case-control study. MPV, platecrit, and PDW levels measured in 37 patients with APAH-CHD and 43 healthy subjects at the beginning of the study. Right heart catheterization was performed in all 37 patients. Clinical and hemodynamic data were collected. All patients were followed from the date of laboratory testing. The study was conducted between March 2012-July 2015. The comparison of clinical, hemodynamic data and platelet indices were made between patients with APAH-CHD who died than APAH-CHD patients who survived.

RESULTS

Of 37 patients, after a mean follow-up duration of 67.90 ± 47.90 months, 11 patients died. MPV (12.10 femoliter [fL; 8.20-12.50] vs 8.70 fL [6.40-9.70], P = .007), PDW (16.88 ± 1.09% vs 15.75 ± 1.58%, P = .04) and platecrit (0.28 ± 0.31 vs 0.22 ± 0.27, P = .01) were significantly higher in the patients with APAH-CHD who died than those who survived. Pearson's correlation analysis showed that MPV correlated with mean pulmonary artery pressure (r = 0.332, P = .04) and correlated negatively with six-minute walking distance (r = -0.600. P = .00). PDW and platecrit correlated positively with mean pulmonary artery pressure (r = 0.373, P = .02; r = 0.389, P = .01, respectively).

CONCLUSION

Our results showed that MPV, platecrit and PDW were increased in children with APAH-CHD. They might give clue about disease severity.

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.

Pseudothrombotic microangiopathy and vitamin B12 deficiency in pernicious anemia

Vitamin B12 deficiency may present as pseudothrombotic microangiopathy. Pseudothrombotic microangiopathy is anemia, thrombocytopenia, and schistocytosis caused by vitamin B12 deficiency. Pseudothrombotic microangiopathy may be mistaken for microangiopathic hemolytic anemia, confounding appropriate treatment. Evaluation of lactate dehydrogenase, reticulocyte count, bilirubin, and platelet count are most helpful in differentiating pseudothrombotic microangiopathy from a true microangiopathic hemolytic anemia. A case of pseudothrombotic microangiopathy due to severe vitamin B12 deficiency is presented.

An Atypical Presentation of Chronic Atrophic Gastritis: Hemolytic Anemia and Mesenteric Panniculitis

Microangiopathic hemolytic anemia (MAHA) requires an aggressive approach since primary thrombotic microangiopathy syndromes such as thrombotic thrombocytopenic purpura (TTP) can progress rapidly to a fatal outcome. Differential diagnosis can be challenging even for an experienced hematologist. We present a case of a 52-year-old male who presented with symptoms of mesenteric panniculitis and showed signs of MAHA. His condition was attributed to severe vitamin B12 deficiency secondary to chronic atrophic gastritis and initiation of appropriate therapy was met with complete resolution of symptoms and normalization of hematologic parameters.

Pseudo-thrombotic thrombocytopenic purpura presenting as multi-organ dysfunction syndrome: A rare complication of pernicious anemia

Objective:

We present a rare case of pernicious anemia presented as multi-organ dysfunction syndrome, later found to have pseudo-thrombotic thrombocytopenic purpura.

Methods:

An 86-year-old female presented with respiratory distress, altered mental status, acute renal failure and was intubated in emergency room. She was found to have severe anemia, thrombocytopenia, high lactate, high lactate dehydrogenase and low haptoglobin. Peripheral smear revealed multilobulated neutrophils with schistocytes, poikilocytes and anisocytes.

Results:

She was admitted to intensive care unit for altered mental status, multi-organ dysfunction syndrome with severe metabolic acidosis in setting of hemolysis. She was intubated and managed with intravenous antibiotics and blood transfusion. Patient improved significantly after blood transfusion. Lactic acid normalized, acute kidney injury resolved and mentation improved after transfusion. Laboratory investigation revealed low vitamin B12, high methylmalonic acid, high homocysteine, high lactate dehydrogenase, low haptoglobin, high anti-parietal antibody and high anti-intrinsic factor antibody. Patient was diagnosed with pernicious anemia and pseudo-thrombotic thrombocytopenic purpura with concomitant intramedullary hemolysis. Her hematological parameters and her clinical condition improved significantly after starting therapy with cyanocobalamin.

Conclusion:

Pernicious anemia is a chronic disease with subtle presentation but may present as life-threatening complications. Hemolysis and pseudo-thrombotic thrombocytopenic purpura may present as multi-organ dysfunction syndrome which has dramatic response to appropriate therapy.

Atypical Hemolytic Uremic Syndrome: A Brief Review

Atypical hemolytic uremic syndrome (aHUS) is a disease characterized by the triad of microangiopathic hemolytic anemia, thrombocytopenia and acute kidney injury. The histopathologic lesions of aHUS include thrombotic microangiopathy involving the glomerular capillaries and thrombosis involving arterioles or interlobar arteries. Extra-renal manifestations occur in up to 20% of patients. The majority of aHUS is caused by complement system defects impairing ordinary regulatory mechanisms. Activating events therefore lead to unbridled, ongoing complement activity producing widespread endothelial injury. Pathologic mutations include those resulting in loss-of-function in a complement regulatory gene (CFH, CFI, CD46 or THBD) or gain-of-function in an effector gene (CFB or C3). Treatment with the late complement inhibitor, eculizumab – a monoclonal antibody directed against C5 – is effective.

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.

When the picture is fragmented: Vitamin B12 deficiency masquerading as thrombotic thrombocytopenic purpura

Thrombotic thrombocytopenic purpura (TTP) has high mortality and necessitates prompt recognition of microangiopathic hemolytic anemia (MAHA) and initiation of plasmapheresis. We present a challenging diagnostic workup and management of a 42-year-old man who presented with anemia, thrombocytopenia, and schistocytes on peripheral smear, all pointing to MAHA. Plasmapheresis and steroid therapy were promptly initiated, but hemolysis continued. Further workup showed megaloblastic anemia, severe Vitamin B₁₂ deficiency, high iron saturation, and absent reticulocytosis, none of which could be explained by TTP. Severe Vitamin B₁₂ deficiency can lead to hemolytic anemia from the destruction of red cells in the marrow that have failed the process of maturation. However, this should not cause thrombotic microangiopathy. Previous reports of B₁₂ deficiency presenting with MAHA and a TTP-like manifestation have identified acute hyperhomocysteinemia as a missing link between B₁₂ deficiency and MAHA, so this possibility was further explored. Our patient similarly had significantly elevated serum homocysteine levels, confirming this suspicion of Vitamin B₁₂ deficiency. Vitamin B₁₂ replacement led to normalization of the elevated levels of homocysteine, the disappearance of schistocytes on the peripheral smear, and resolution of the microangiopathic hemolysis, thereby confirming the diagnosis. It is pertinent that intensivists not only know the importance of early recognition and treatment of TTP but are also familiar with rare conditions that can present in a similar fashion.

An Unusual Presentation of Pseudothrombotic Microangiopathy in a Patient with Autoimmune Atrophic Gastritis

Introduction. We hereby describe the case of a young female patient who presented with pseudothrombotic microangiopathy, as well as pancytopenia accompanied by autoimmune atrophic gastritis. Case Presentation. A 36-year-old Caucasian woman presented to the emergency department with fatigue and dyspnea on minimal exertion. Physical examination was unremarkable except for pallor and noninjected conjunctiva. Laboratory tests revealed high LDH and low hemoglobin, white blood cells, platelets, and haptoglobin. The peripheral blood smear showed schistocytes suggestive of pseudothrombotic microangiopathy. Low cobalamin level and hyperhomocysteinemia were also detected. Autoimmune atrophic gastritis was confirmed by gastric biopsy and positive anti-intrinsic factor antibodies. Vitamin B12 supplements were given which led to rapid recovery and normalization of blood parameters. Conclusion. This case highlights the importance and serves as a reminder to clinicians to rule out cobalamin deficiency and autoimmune atrophic gastritis in patients presenting with a picture suggestive of thrombotic thrombocytopenic purpura and pancytopenia, which was completely reversible after appropriate replacement therapy without recurring to unnecessary and invasive procedures such as plasma exchange.

Therapeutic dilemma in the management of a patient with the clinical picture of TTP and severe B12 deficiency

Background

Idiopathic thrombotic thrombocytopenic purpura (TTP) is a rare hematological emergency characterized by the pentad of microangiopathic hemolytic anemia, thrombocytopenia, neurological symptoms, renal injury, and fever that is invariably fatal if left untreated. Prompt intervention with plasma exchange minimizes mortality and is the cornerstone of therapy. Rare reports have described “pseudo-TTP” driven by extreme hematologic abnormalities resulting from deficiency of vitamin B₁₂. Distinguishing between these entities can pose a diagnostic and therapeutic challenge.

Case presentation

A 77 year old female presented with altered mental status, renal insufficiency, thrombocytopenia and evidence of microangiopathic hemolytic anemia, suggesting TTP. Workup demonstrated macrocytosis and reticulocytopenia, and B₁₂ level was unmeasurably low. Other elements of her clinical presentation, including volume loss and bleeding suggested a multifactorial pathogenesis could be contributing to her laboratory abnormalities, reducing the likelihood that she had TTP. The risks and benefits of treating aggressively with therapeutic plasma exchange (TPE) for TTP were considered given the diagnostic possibilities. The patient received TPE initially, with rapid de-escalation after her clinical response suggested “pseudo-TTP” from B₁₂ deficiency was the driving the process. B₁₂ supplementation corrected her hematologic abnormalities and she remains well two years after presenting.

Conclusions

TTP is a rare condition with fatal consequences if left untreated. Guidelines recommend TPE even if there is uncertainty about the diagnosis of TTP. B₁₂ deficiency is common, though not typically associated with severe hematologic abnormalities. We compare the presenting characteristics of all thirteen cases of pseudo-TTP reported in the literature with those from patients in case series of TTP to suggest a set of parameters that can help clinicians distinguish between pseudo-TTP and TTP and guide decision making regarding intervention. Evaluation of all TTP cases should include a B₁₂, methylmalonic acid level and reticulocyte count. Reticulocytopenia suggests B₁₂ deficiency. Finally an LDH level above 2500 IU/L is relatively uncommon in TTP and should suggest consideration of B₁₂ deficiency.