Thrombotic microangiopathy after kidney transplantation: Expanding etiologic and pathogenetic spectra

Thrombotic microangiopathy(TMA)is an uncommon but serious complication that not only affects native kidneys but also transplanted kidneys.This review is specifically focused on post-transplant TMA(PT-TMA)involving kidney transplant recipients.Its reported prevalence in the latter population varies from 0.8%to 14%with adverse impacts on both graft and patient survival.It has many causes and associations,and the list of etiologic agents and associations is growing constantly.The pathogenesis is equally varied and a variety of pathogenetic pathways lead to the development of microvascular injury as the final common pathway.PT-TMA is categorized in many ways in order to facilitate its management.Ironically,more than one causes are contributory in PT-TMA and it is often difficult to pinpoint one particular cause in an individual case.Pathologically,the hallmark lesions are endothelial cell injury and intravascular thrombi affecting the microvasculature.Early diagnosis and classification of PT-TMA are imperative for optimal outcomes but are challenging for both clinicians and pathologists.The Banff classification has addressed this issue and has developed minimum diagnostic criteria for pathologic diagnosis of PT-TMA in the first phase.Management of the condition is also challenging and still largely empirical.It varies from simple maneuvers,such as plasmapheresis,drug withdrawal or modification,or dose reduction,to lifelong complement blockade,which is very expensive.A thorough understanding of the condition is imperative for an early diagnosis and quick treatment when the treatment is potentially effective.This review aims to increase the awareness of relevant stakeholders regarding this important,potentially treatable but under-recognized cause of kidney allograft dysfunction.

Glucocorticoid-induced thrombotic microangiopathy in paroxysmal nocturnal hemoglobinuria:A case report and review of literature

BACKGROUND Thrombotic microangiopathy(TMA)is a group of disorders that converge on excessive platelet aggregation in the microvasculature,leading to consumptive thrombocytopenia,microangiopathic hemolysis and ischemic end-organ dysfunction.In predisposed patients,TMA can be triggered by many environmental factors.Glucocorticoids(GCs)can compromise the vascular endothelium.However,GC-associated TMA has rarely been reported,which may be due to the lack of awareness of clinicians.Given the high frequency of thrombocytopenia during GC treatment,particular attention should be given to this potentially fatal complication.CASE SUMMARY An elderly Chinese man had a 12-year history of aplastic anemia(AA)and a 3-year history of paroxysmal nocturnal hemoglobinuria(PNH).Three months earlier,methylprednisolone treatment was initiated at 8 mg/d and increased to 20 mg/d to alleviate complement-mediated hemolysis.Following GC treatment,his platelet counts and hemoglobin levels rapidly decreased.After admission to our hospital,the dose of methylprednisolone was increased to 60 mg/d in an attempt to enhance the suppressive effect.However,increasing the GC dose did not alleviate hemolysis,and his cytopenia worsened.Morphological evaluation of the marrow smears revealed increased cellularity with an increased percentage of erythroid progenitors without evident dysplasia.Cluster of differentiation(CD)55 and CD59 expression was significantly decreased on erythrocytes and granulocytes.In the following days,platelet transfusion was required due to severe thrombocytopenia.Observation of platelet transfusion refractoriness indicated that the exacerbated cytopenia may have been caused by the development of TMA due to GC treatment because the transfused platelet concentrates had no defects in glycosylphosphatidylinositol-anchored proteins.We examined blood smears and found a small number of schistocytes,dacryocytes,acanthocytes and target cells.Discontinuation of GC treatment resulted in rapidly increased platelet counts and steady increases in hemoglobin levels.The patient’s platelet counts and hemoglobin levels returned to the levels prior to GC treatment 4 weeks after GC discontinuation.CONCLUSION GCs can drive TMA episodes.When thrombocytopenia occurs during GC treatment,TMA should be considered,and GCs should be discontinued.

Pulmonary tumor thrombotic microangiopathy of hepatocellular carcinoma: A case report and review of literature

BACKGROUND Pulmonary tumor thrombotic microangiopathy(PTTM)is a rare condition in patients with hepatocellular carcinoma(HCC);to date,few cases have been reported.While hepatic dysfunction has been focused on the later stages of HCC,the management of symptoms in PTTM is important for supportive care of the cases.For the better understanding of PTTM in HCC,the information of our recent case and reported cases have been summarized.CASE SUMMARY A patient with HCC exhibited acute and severe respiratory failure.Radiography and computed tomography of the chest revealed the multiple metastatic tumors and a frosted glass–like shadow with no evidence of infectious pneumonia.We diagnosed his condition as acute respiratory distress syndrome caused by the lung metastases and involvement of the pulmonary vessels by tumor thrombus.Administration of prednisolone to alleviate the diffuse alveolar damages including edematous changes of alveolar wall caused by the tumor cell infiltration and ischemia showed mild improvement in his symptoms and imaging findings.An autopsy showed the typical pattern of PTTM in the lung with multiple metastases.CONCLUSION PTTM is caused by tumor thrombi in the arteries and thickening of the pulmonary arterial endothelium leading to the symptoms of dyspnea in terminal staged patients.Therefore,supportive management of symptoms is necessary in the cases with PTTM and hence we believe that the information presented here is of great significance for the diagnosis and management of symptoms of PTTM with HCC.

Thrombotic microangiopathy after renal transplantation: Current insights in de novo and recurrent disease

Thrombotic microangiopathy(TMA) is one of the most devastating sequalae of kidney transplantation. A number of published articles have covered either de novo or recurrent TMA in an isolated manner. We have, hereby, in this article endeavored to address both types of TMA in a comparative mode. We appreciate that de novo TMA is more common and its prognosis is poorer than recurrent TMA; the latter has a genetic background, with mutations that impact disease behavior and, consequently, allograft and patient survival. Post-transplant TMA can occur as a recurrence of the disease involving the native kidney or as de novo disease with no evidence of previous involvement before transplant. While atypical hemolytic uremic syndrome is a rare disease that results from complement dysregulation with alternative pathway overactivity, de novo TMA is a heterogenous set of various etiologies and constitutes the vast majority of post-transplant TMA cases. Management of both diseases varies from simple maneuvers, e.g., plasmapheresis, drug withdrawal or dose modification, to lifelong complement blockade, which is rather costly. Careful donor selection and proper recipient preparation, including complete genetic screening, would be a pragmatic approach. Novel therapies, e.g., purified products of the deficient genes, though promising in theory, are not yet of proven value.

Broad spectrum of interferon-related nephropathies-glomerulonephritis,systemic lupus erythematosus-like syndrome and thrombotic microangiopathy:A case report and review of literature

BACKGROUND Interferons(IFNs)are characterized by a wide range of biological effects,which justifies their potential therapeutic use in several pathologies,but also elicit a wide array of adverse effects in almost every organ system.Among them,renal involvement is probably one of the most complex to identify.CASE SUMMARY We describe four cases of kidney damage caused by different IFN formulations:IFN-β-related thrombotic microangiopathy,IFN-β-induced systemic lupus erythematosus,and two cases of membranous nephropathy secondary to pegylated-IFN-α2B.In each case,we carefully excluded any other possible cause of renal involvement.Once suspected as the casual relationship between drug and kidney damage,IFN treatment was immediately discontinued.In three cases,we observed a complete and persistent remission of clinical and laboratory abnormalities after IFN withdrawal,while the patient who developed thrombotic microangiopathy,despite IFN withdrawal and complement-inhibitor therapy with eculizumab,showed persistent severe renal failure requiring dialysis.CONCLUSION This case series highlights the causal relationship between IFN treatment and different types of renal involvement and enables us to delineate several peculiarities of this association.

Acute liver failure with thrombotic microangiopathy due to sodium valproate toxicity:A case report

BACKGROUND Sodium valproate is widely used in the treatment of epilepsy in clinical practice.Most adverse reactions to sodium valproate are mild and reversible,while serious idiosyncratic side effects are becoming apparent,particularly hepatotoxicity.Herein,we report a case of fatal acute liver failure(ALF)with thrombotic microangiopathy(TMA)caused by treatment with sodium valproate in a patient following surgery for meningioma.CASE SUMMARY A 42-year-old man who received antiepileptic treatment with sodium valproate after surgery for meningioma exhibited extreme fatigue,severe jaundice accompanied by oliguria,soy sauce-colored urine,and ecchymosis.His postoperative laboratory values indicated a rapid decreased platelet count and hemoglobin level,severe liver and kidney dysfunction,and disturbance of the coagulation system.He was diagnosed with drug-induced liver failure combined with TMA.After plasma exchange combined with hemoperfusion,pulse therapy with high-dose methylprednisolone,and blood transfusion,his liver function deteriorated,and finally,he died.CONCLUSION ALF with TMA is a rare and fatal adverse reaction of sodium valproate which needs to be highly valued.

Transplant-associated thrombotic microangiopathy:a rare but deadly complication post orthotopic heart transplantation

Thrombotic microangiopathy(TMA)is potentially life-threatening condition caused by small-vessel microthrombi and is associated with schistocyte formation,low platelets and end-organ damage that may not be reversible.[1,2]As a life-threatening condition,TMA recognition in hospitalized patients after organ transplantation is key to improving survival.Transplant-associated TMA(TATMA)can occur after both solid organ or hematopoietic stem cell transplantation and often mimics other disease processes such as thrombotic throm-bocytopenic purpura(TTP)with similar constellation of symptoms during presentation.We present a rare case of a patient with TATMA after orthotopic heart transplantation.

Relationships Between Superoxide Anion and Microangiopathy in Non-Insulin-Dependent Diabetes Mellitus

Concentration of supemxide anion in plasma and ecythrocytes in 21 patients with non-Insulin-dependent diabetes mellitus (NIDDM)(14 with complicating microangiopathy) and 34 normal adults was assayed by chemiluinesence. Both plasma and erythrocyte concentration of .0-2 were ekvated in NIDDM with complicating microangiopathy beyond normal range (P<0.01),whereas in NIDDM without microangiopathy,in plasma was only slightly raised and RBC(.0-2) was within normal range. The authors think that RBC (.0-2) may be used as an indicator for the detection of presence of microangiopathy in NIDDM.

Changes in macrophage infiltration and podocyte injury in lupus nephritis patients with repeated renal biopsy: Report of three cases

BACKGROUND In this study,we retrospectively analysed macrophage infiltration and podocyte injury in three patients with diffuse proliferative lupus nephritis(LN)who un-derwent repeated renal biopsy.CASE SUMMARY Clinical data of three diffuse proliferative LN patients with different pathological characteristics(case 1 was LN IV-G(A),case 2 was LN IV-G(A)+V,and case 3 was LN IV-G(A)+thrombotic microangiopathy)were reviewed.All patients underwent repeated renal biopsies 6 mo later,and renal biopsy specimens were studied.Macrophage infiltration was assessed by CD68 expression detected by immunohistochemical staining,and an immunofluorescence assay was used to detect podocin expression to assess podocyte damage.After treatment,Case 1 changed to LN III-(A),Case 2 remained as type V LN lesions,and Case 3,which changed to LN IV-S(A),had the worst prognosis.We observed reduced macro-phage infiltration after therapy.However,two of the patients with active lesions after treatment still showed macrophage infiltration in the renal interstitium.Before treatment,the three patients showed discontinuous expression of podocin.Notably,the integrity of podocin was restored after treatment in Case 1.CONCLUSION It may be possible to reverse podocyte damage and decrease the infiltrating ma-crophages in LN patients through effective treatment.

The relationship between concentration of growth hormone in serum and microangiopathy in patients with diabetes mellitus.

Objective To study the relationship between growth hormone (GH) and microangiopathy in patients with diabetes mellitus in order to elucidate pathogenesis on microangiopathy in diabetics. Methods GH and insulin (INS) were detected by radioimmunoassay, and blood sugar (BS) was detected by oxydase method. Results 138 NIDDM diabetics were examined. The concentration of serum GH in diabetics without microangiopathy (2.3±1.2 μg/L) was higher than in normal people (1.0±1.2 μg/L) and GH in diabetics with microangiopathy (5.74±1.94 μg/L) was higher than in diabetics without microangiopathy. The differences were significant ( P <0.01). As the history of diabetes went on, the level of GH in serum increased, and the incidence of microangiopathy increased too. The correlation of GH in serum with BS was parallel. The correlation of GH in serum with INS was not apparent. 27 IDDM diabetics were examined, their level of GH in serum (6.8±3.4 μg/L) was higher than that of NIDDM diabetics (4.6±1.8 μg/L). They were all patients with microangiopathy. Conclusion The rise of GH in serum may be an important pathogeny that causes microangiopathy in diabetics.

Post-traumatic thrombotic microangiopathy: What trauma surgeons need to know?

Thrombotic microangiopathy(TMA)is characterized by systemic microvascular thrombosis,target organ injury,anemia and thrombocytopenia.Thrombotic thrombocytopenic purpura,atypical hemolytic uremic syndrome and Shiga toxin E-coli-related hemolytic uremic syndrome are the three common forms of TMAs.Traditionally,TMA is encountered during pregnancy/postpartum period,malignant hypertension,systemic infections,malignancies,autoimmune disorders,etc.Recently,the patients presenting with trauma have been reported to suffer from TMA.TMA carries a high morbidity and mortality,and demands a prompt recognition and early intervention to limit the target organ injury.Because trauma surgeons are the first line of defense for patients presenting with trauma,the prompt recognition of TMA for these experts is critically important.Early treatment of post-traumatic TMA can help improve the patient outcomes,if the diagnosis is made early.The treatment of TMA is also different from acute blood loss anemia namely in that plasmapheresis is recommended rather than platelet transfusion.This article familiarizes trauma surgeons with TMA encountered in the context of trauma.Besides,it provides a simplified approach to establishing the diagnosis of TMA.Because trauma patients can require multiple transfusions,the development of disseminated intravascular coagulation must be considered.Therefore,the article also provides different features of disseminated intravascular coagulation and TMA.Finally,the article suggests practical points that can be readily applied to the management of these patients.

Variable clinical manifestations of hematopoietic stem cell transplant-associated thrombotic microangiopathy

INTRODUCTIONTransplantation-associated thrombotic microangiopathy (TA-TMA) is a complication of hematopoietic stem cell transplantation (HSCT) characterized by small vessel endothelial damage leading to thrombosis and fibrin deposition resulting in hemolytic anemia and thrombocytopenia. The severity of TA-TMA varies from mild self-limited disease to a fulminant variant resulting in death. Here, we review two rare cases and review the literature of TA-TMA.

Advances in cardiovascular-related biomarkers to predict diabetic peripheral neuropathy

Diabetic peripheral neuropathy(DPN)is a common chronic complication of diabetes mellitus.One of the most common types is distal symmetric polyneuropathy,which begins as bilateral symmetry pain and hyperesthesia and gradually progresses into hypoesthesia with nerve fibre disorder and is frequently accompanied by depression and anxiety.Notably,more than half of patients with DPN can be asymptomatic,which tends to delay early detection.Furthermore,the study of adverse outcomes showed that DPN is a prominent risk factor for foot ulceration,gangrene and nontraumatic amputation,which decreases quality of life.Thus,it is essential to develop convenient diagnostic biomarkers with high sensitivity for screening and early intervention.It has been reported that there may be common pathways for microvascular and macrovascular complications of diabetes.The pathogenesis of both disorders involves vascular endothelial dysfunction.Emerging evidence indicates that traditional and novel cardiovascularrelated biomarkers have the potential to characterize patients by subclinical disease status and improve risk prediction.Additionally,beyond traditional cardiovascular-related biomarkers,novel cardiovascular-related biomarkers have been linked to diabetes and its complications.In this review,we evaluate the association between major traditional and nontraditional car-diovascular-related biomarkers of DPN,such as cardiac troponin T,B-type natriuretic peptide,Creactive protein,myeloperoxidase,and homocysteine,and assess the evidence for early risk factor-based management strategies to reduce the incidence and slow the progression of DPN.

Expression and Significance of fgl2 Prothrombinase in Cardiac Microvascular Endothelial Cells of Rats with Type 2 Diabetes

Microthrombosis may be involved in the pathogenesis of cardiac microangiopathy due to diabetes.Recent studies have shown that fibrinogen-like protein 2 (fgl2) plays a pivotal role in microthrombosis in viral hepatitis, acute vascular xenograft rejection and cytokine-induced fetal loss syndrome.The current study was designed to examine the expression of fgl2 in microvascular endothelial cells and investigate the effects of microthrombi due to fgl2 on cardiac function and structure in rats with type 2 diabetes.Following induction of type 2 diabetes, 24 rats were observed dynamically.Fgl2 expression and related cardiac microthrombosis were examined.Local or circulating TNF-α was measured.Coronary flow (CF) per min was calculated as an index of cardiac microcirculation.Cardiac function and morphology were evaluated.It was found that Fgl2 was highly expressed in cardiac microvascular endothelial cells of rats with type 2 diabetes, which was promoted by local or circulating TNF-α.The Fgl2 expression was associated with cardiac hyaline microthrombosis.In parallel with the fgl2 expression, CF per min, cardiac diastolic or systolic function and cardiac morphology were aggravated to some extent.It was concluded that in rats with type 2 diabetes, microthrombosis due to fgl2 contributes to the impairment of cardiac diastolic or systolic function and morphological changes.

Gastrointestinal infection-related disseminated intravascular coagulation mimicking Shiga toxin-mediated hemolytic uremic syndrome-implications of classical clinical indexes in making the diagnosis:A case report and literature review

BACKGROUND Thrombocytopenia associated with acute kidney injury is a challenging disorder. Thrombotic microangiopathy (TMA) is a potentially life- or organ-threatening syndrome that can be induced by several disorders or medical interventions. There is overlap between the clinical presentation and pathophysiology of thrombotic thrombocytopenia purpura and hemolytic uremic syndrome (HUS), and to a lesser extent, disseminated intravascular coagulation (DIC). We describe a case to illustrate the potential diagnostic difficulty, especially at initial presentation. CASE SUMMARY We reported a case of a 44-year-old woman that presented with diarrhea, thrombocytopenia, schistocytes, elevated serum lactate dehydrogenase (LDH) level and acute kidney injury. While the clinical presentation resembled that of Shiga toxin–induced HUS, the disease course was more consistent with gastrointestinal infection-related DIC. To aid in the accurate diagnosis of TMA and other associated disorders, we have undertaken a review and provided a clear interpretation of some typical biomarkers including schistocytes, LDH and platelet count, coagulation profile and more specific indexes of ADAMTS13, complement profile, and the isolation of Shiga toxin-producing Escherichia coli (commonly referred to as STEC). CONCLUSION The use and correct interpretation of classical indexes of schistocyte, LDH, and platelet count is vital in diagnosing TMA and associated disorders. Understanding the characteristics of these biomarkers in the context of thrombocytopenia purpura, HUS and DIC will facilitate the accurate diagnosis and early initiation of appropriate treatment.

MicroRNA profiling in sera of patients with type 2 diabetes mellitus reveals an upregulation of miR-31 expression in subjects with microvascular complications

Type 2 diabetes (T2D) is a metabolic disease characterized by chronic hyperglycaemia due to a combination of resistance to insulin action and an inadequate compensatory insulin secretory response. Chronic hyperglycemia is associated with long-term micro- and macrovascular complications leading to dysfunction of several organs including kidney, heart, eye and nervous system. Early identification of chronic diabetic complications is necessary in order to prevent dysfunction and failure of these different organs. MicroRNAs (or miRNAs) are small endogenous RNAs, which negatively regulate gene expression. Recently, it has been demonstrated that miRNAs can be secreted by cells, thus being detectable in serum and in other biological fluids. Circulating microRNAs have been proposed as possible biomarkers of several diseases. Here, we performed a miRNAs expression profiling in the sera of T2D patients with or without vascular complications in order to find specific biomarkers to characterize T2D complications. We analyzed the expression of 384 microRNAs in serum pools from 3 groups of T2D patients: 12 T2D patients without any chronic complications, 12 T2D patients with macrovascular complications and 12 with microvascular complications. We found 223 miRNAs expressed in T2D,224 inT2D with microvascular and221 inT2D with macrovascular complications. Among expressed microRNAs, 45 resulted upregulated and 23 downregulated in microvascular patients sera, while 13 upregulated and 41 downregulated in macrovascular T2D patients compared to those without complications. We focused and validated microRNA miR-31 expression in single sera from each group, which resulted significantly upregulated in patients with microvascular complications and may be indeed related to the presence of microangiopathy. In conclusion, our study has identified miR-31 as a promising biomarker for diabetic microvascular complications;further prospective studies in the clinical setting are however required to establish the real utility of measuring serum circulating levels of this microRNA.

Fluorescent advanced glycation end-products (ages) detected by spectro-photofluorimetry, as a screening tool to detect diabetic microvascular complications

BACKGROUND: Advanced glycation end-products (AGEs) are one of the mechanisms related to diabetic vascular complications. However, since AGEs are multiple and heterogeneous moieties, there is no universally accepted method to measure them for clinical purposes. The aim of this work was to study the utility of a simple fluorimetric assay as predictor of complications. METHODS: Blood samples from 102 type 2 diabetic patients were obtained to assess glucose, glycosylated haemoglobin, creatinine, lipoproteins and C Reactive Protein (CRP), fluorescent AGES by spectrophotofluorimetry and non-fluorescent AGEs by measurement of N(ε)-carboxymethyl-Lysine (CML) using an ELISA kit in a subsample of 82 patients. Urinary fluorescent AGEs, albumin and creatinine were also measured in a morning urine sample. Microvascular complications were studied by ophthalmologic examination, albuminuria and peripheral nerve conduction velocity. RESULTS: Patients without microvascular complications had significantly lower levels of both serum and urinary AGEs. CML was associated with retinopathy. Multiple regression analysis confirmed that AGEs, length of diabetes and glycosylated haemoglobin were all variables associated with diabetic complications, in this sample. CONCLUSIONS: A simple fluorimetric assay to measure low molecular weight fluorescent AGEs, and CML could be employed as screening tools to predict diabetic complications, at a primary care setting. AGEs should probably be considered as another therapeutic target in diabetes management.

Gemcitabine-induced haemolytic uremic syndrome,although infrequent,can it be prevented:A case report and review of literature

Gemcitabine is an antineoplastic used to treat several malignancies including pancreatic cancer. Its toxicity profile is well known with myelotoxicity, increased vascular permeability and peripheral oedema as most frequent adverse events. However, several cases of acute renal failure have been reported and haemolytic uremic syndrome(HUS) seems to be the underlying process. The cause of HUS remains unknown but its consequences can be lethal. Therefore, a high grade of suspicion is crucial to diagnose it and promptly treat it. This hopefully will reduce its morbidity. HUS is characterized by progressive renal failure associated with microangiopathic haemolytic anaemia and thrombocytopenia. The primary event is damage to endothelial cells and thrombotic microangiopathy(TMA) is the histopathological lesion. TMA affects mainly renal microvasculature. However, some cases evolve with central nervous or cardiovascular systems involvement. We present here a case of gemcitabine-induced HUS, with renal and cardiovascular system affected at the time of diagnosis which to our knowledge this is the first time of such case to be reported.

Diagnostic Approach of Thrombocytopenia in Pregnancy: A Review

Thrombocytopenia (defined as platelet count 9/L) is present in 7% - 12% of pregnant women at delivery. Although there are mild etiologies of this condition that are often diagnosed incidentally, there are more severe causes that can be life threating. Thrombocytopenia also has a great implication in surgical risk and regional anesthesia. A structured evaluation of thrombocytopenia is necessary to allow an adequate diagnostic approach. Here we summarized the current knowledge of thrombocytopenia in pregnancy.

Correlation between Glomerulopathy and Retinopathy in an African Population of Type 2 Diabetics

Introduction: Diabetic microangiopathies are common, but their time to onset in a diabetic patient varies from subject to subject. The aim of our study was to study the correlation between renal and ophthalmic disorders in patients with type 2 diabetes. Patients and methods: This longitudinal, analytical study took place from March 1, 2018 to March 31, 2019 at the Abass Ndao University Hospital Center. It was studying retinal involvement in diabetic patients with glomerulopathy. Results: Of the 100 cases of diabetic glomerulopathy, they are divided into 70 women and 30 men with an average age of 58.2 years. The average duration of diabetes was 6.1 years and their average glycated hemoglobin (HbA1c) was 8.1%. Only 37% of patients had an HbA1c level below 7%. The other cardiovascular risk factors were high blood pressure (HBP) (39%), dyslipidemia (36%), and obesity (15%). Among these patients, diabetic retinopathy was present in 21% of the cases. Retinopathies were more frequent in the group of patients diagnosed with diabetes for less than 6 years (69%) and in patients with chronic renal disease with slightly reduced glomerular filtration rate (GFR) (34%). Conclusion: Our study allowed us to conclude that during the course of type 2 diabetes, the onset of chronic kidney disease does not systematically imply the presence of diabetic retinopathy. It is thus important to make screenings and assessments of systematic complications.