Hemolytic Uremic Syndrome: A Case Report.

Thrombotic microangiopathy is a pathological condition comprised of microvascular thrombosis involving any body organ leading to thrombocytopenia, coombs-negative hemolytic anemia, and end-organ damage. The clinical presentation of the case shows typical hemolytic uremic syndrome, however, lab reports show atypical hemolytic uremic syndrome (low C3). Pain abdomen and loose stool with some signs of dehydration were initial presentations. Early initiation of renal replacement therapy and management of dehydration was done. Simple diarrhea can also manifest as acute kidney injury with the hemolytic uremic syndrome. Hence we should keep hemolytic uremic syndrome as the differential diagnosis of diarrhea. Irrespective of lab parameters, early management in line with the typical hemolytic uremic syndrome should be done for better outcomes. Keywords: anemia; case reports; dehydration; renal replacement therapy.

Utility of Different Scoring Systems for the Diagnosis of Thrombotic Microangiopathies.

OBJECTIVE:  To investigate the appropriateness of Bentley and plasmic scores and ADAMTS-13 activity to distinguish between primary thrombotic microangiopathies (TMA) syndromes and other thrombotic microangiopathies, as well as primary thrombotic microangiopathies (TTP, complement-related TMA, etc). STUDY DESIGN:  Descriptive study. Place and Duration of the Study: Department of Hematology, Faculty of Medicine, from February 2013 to February 2020. METHODOLOGY: Data of patients with non-immune hemolytic anaemia (MAHA) and thrombocytopenia who had ADAMTS-13 test, were analysed. Clinical and laboratory findings, Bentley and plasmic scores, and ADAMTS activity levels were compared. RESULTS: The patients were grouped as primary (n = 27) and secondary (n = 28) TMA, the age was median 38.0 (18-63) years in the primary TMA group and 49.5 (20-84) years in the secondary TMA group. Neurological findings were less in the secondary TMA group (p = 0.008). Plasmic score, lactate dehydrogenase, and total and indirect bilirubin levels were high and D-dimer levels were low in the primary TMA group. In the primary TMA group, a greater number of patients with high plasmic scores were found, whereas all patients in the secondary TMA group had low risk according to Bentley score. Calcium levels were high and platelet levels were low in those with ADAMTS activity level <10% (p = 0.006). The evaluation of primary TMAs demonstrated significant differences in platelet, urea, creatinine, and sodium values between the two groups. CONCLUSION: Laboratory data and clinical scores are valuable in differentiating primary and other TMA. KEY WORDS: Bentley score, Complement, Plasmic score, Thrombotic microangiopathy, Thrombotic thrombocytopenic purpura, ADAMTS-13.

Complement-Mediated Thrombotic Microangiopathy and Spontaneous Splenic Rupture Associated With Cytomegalovirus Infection.

This is a case report of a previously healthy female patient with complement-mediated thrombotic microangiopathy (TMA) caused by a systemic cytomegalovirus infection that was successfully treated with plasmapheresis, steroids, and parenteral valganciclovir. Complement-mediated TMA is the result of various genetic mutations leading to complement abnormalities with overactivation of alternate complement pathway in response to a triggering infection. She also had splenic rupture without splenomegaly and was managed successfully without splenectomy.

[Thrombotic microangiopathy with gastrointestinal hemorrhage during carfilzomib therapy for multiple myeloma].

A 70-year-old woman was admitted to the hospital with loss of appetite and melena. She was diagnosed with multiple myeloma 7 years ago and had been on carfilzomib, lenalidomide, and dexamethasone (KRd) therapy for a month because her disease had a relapsed/refractory. On admission, her laboratory tests revealed hemolytic anemia with schizocytes, thrombocytopenia, and acute renal dysfunction. TMA (thrombotic microangiography) caused by carfilzomib was suspected. The possibility of thrombotic thrombocytopenia was considered, and steroid pulse therapy was initiated. Her condition improved significantly after she stopped taking carfilzomib, plasma exchange, hemodiafiltration, steroid pulse therapy, and abstaining from food. The previously reported cases of carfilzomib-induced TMA included fever, gastrointestinal symptoms (nausea/vomiting, diarrhea), and acute renal disorders (lower extremity edema, decreasing urine output). As far as we know, this is the first case of carfilzomib-induced TMA with bleeding as the first symptom.

Performance Validation of Three Scoring Systems for the Prediction of Thrombotic Microangiopathy Due to Severe ADAMTS13 Deficiency and the Response to Therapeutic Plasma Exchange: First Study in Korea.

Background: The BENTLEY score (B-S), French thrombotic microangiopathy (TMA) Reference Center score (FTMA-S), and PLASMIC score (PLASMIC-S) have been developed for TMA diagnostic prediction. We retrospectively validated their predictive performances in patients with severe (<10%) disintegrin and metalloprotease with thrombospondin type 1 motif, member 13 (ADAMTS13) deficiency in terms of the risk of TMA and response to therapeutic plasma exchange (TPE). Methods: The predictive performances of the three scoring systems were compared in 145 patients with suspected TMA who underwent ADAMTS13 activity tests between January 2014 and September 2022. The response to TPE and mortality in TMA-positive patients were compared after risk stratification, using the Mann-Whitney U and Fisher's exact tests. Results: The PLASMIC-S, FTMA-S, and B-S showed area under the curve values of 0.820, 0.636, and 0.513, respectively, for predicting TMA positivity in high-risk patients. The PLASMIC-S showed higher sensitivity (81.8%), negative predictive value (91.2%), positive predictive value (PPV; 66.7%), and accuracy (82.1%) than the FTMA-S (72.7%, 82.1%, 41.0%, and 60.0%, respectively) and B-S (4.6%, 70.2%, 50.0%, and 69.7%, respectively). The PLASMIC-S also showed higher specificity than the FTMA-S (82.2% vs. 54.5%). The modified PLASMIC-S, including lactate dehydrogenase/upper limit of normal ratios, increased the specificity, PPV, and accuracy to 97.0%, 92.3%, and 92.4%, respectively. In TMA-positive patients, high risk assessed by the PLASMIC-S predicted higher platelet recovery rates and less TPE sessions required for recovery than for those assessed at low-to-intermediate risk. Conclusions: PLASMIC-S is the preferred scoring system for detecting patients with TMA positivity and for prognosis before confirmation of ADAMTS13 activity.

Bilateral Proliferative Retinopathy as the Initial Presentation of Atypical Hemolytic Uremic Syndrome: A Case Report.

In this case report, we describe a 34-year-old male patient who presented with vision loss and was found to have profound occlusive retinal vasculopathy. His initial laboratory studies were unremarkable, but five weeks after his ocular symptoms began, he developed acute multi-organ failure and was ultimately diagnosed with atypical hemolytic uremic syndrome (aHUS). His course was complicated by a stroke, respiratory distress requiring intubation, long-term hemodialysis, and eventually death. Occlusive retinal vasculopathy may be the presenting finding in aHUS, although thrombotic microangiopathy syndromes typically present with acute kidney injury and or failure, hemolytic anemia, and thrombocytopenia. [Ophthalmic Surg Lasers Imaging Retina 2023;54:297-300.].

[Advances in Diagnosis and Treatment of Transplant-Associated Thrombotic Microangiopathy --Review].

Transplantation-associated thrombotic microangiopathy (TA-TMA) is one of the serious complications mostly occurring within 100 days after hematopoietic stem cell transplantation (HSCT). Risk factors of TA-TMA include genetic predispositions, GVHD, and infections. The pathophysiological mechanisms of TA-TMA start with endothelial injury caused by complement activation, which leads to microvascular thrombosis, and microvascular hemolysis, ultimately resulting in multi-organ dysfunction. In recent years, the development of complement inhibitors has markedly improved the prognosis of TA-TMA patients. This review will give an update on risk factors, clinical manifestations, diagnosis, and treatment of TA-TMA, so as to provide references for clinical practice.

Catastrophic antiphospholipid syndrome accompanied by complement regulatory gene mutation.

BACKGROUND: Antiphospholipid syndrome (APS), particularly the catastrophic antiphospholipid syndrome (CAPS), is one of the rare causes of thrombotic microangiopathy (TMA). CAPS is the most severe form of APS, especially when accompanied by complement dysregulation, causes progressive microvascular thrombosis and failure in multiple organs. In this report, a case of CAPS with TMA accompanied by a genetic defect in the complement system is presented. CASE: A 13-year-old girl was admitted to the hospital with oliguric acute kidney injury, nephrotic range proteinuria, Coombs positive hemolysis, refractory thrombocytopenia, a low serum complement C3 level and anti-nuclear antibody (ANA) positivity. The kidney biopsy was consistent with TMA. She was first diagnosed with primary APS with clinical and pathological findings and double antibody positivity. As initial treatments, plasmapheresis (PE) was performed and eculizumab was also administered following pulsesteroid and intravenous immunoglobulin treatments. Her renal functions recovered and she was followed up with mycophenolate mofetil, hydroxychloroquine, low dose prednisolone and low molecular weight heparin treatments. The patient presented with severe chest pain, vomiting and acute deterioration of renal functions a few months after the diagnosis of TMA. A CAPS attack was considered due to radiological findings consistent with multiple organ thrombosis and intravenous cyclophosphamide (CYC) was given subsequent to PE. After pulse CYC and PE treatments, her renal functions recovered, she is still being followed for stage-3 chronic kidney disease. Complement factor H-related protein I gene deletion was detected in the genetic study. CONCLUSIONS: The clinical course of complement mediated CAPS tends to be worse. Complement system dysregulation should be investigated in all CAPS patients, and eculizumab treatment should be kept in mind if detected.

Pulmonary tumor thrombotic microangiopathy during good response to immuno-chemotherapy for advanced non-small cell lung cancer: a case report.

BACKGROUND: Pulmonary tumor thrombotic microangiopathy is a rapidly progressive and fatal disease in which tumor cells embolize to the pulmonary microvasculature. This condition is characterized by severe dyspnea and right heart failure. Although pulmonary tumor thrombotic microangiopathy typically occurs in patients with untreated and/or advanced cancer, its occurrence in patients who are responding well to medical therapy is poorly documented. CASE PRESENTATION: A 68-year-old Japanese woman who had received four cycles of immuno-chemotherapy (pembrolizumab, carboplatin, and pemetrexed) followed by three cycles of maintenance therapy (pembrolizumab and pemetrexed) for advanced non-small cell lung cancer and had achieved a partial response with a stable clinical course was admitted to the emergency ward because of worsening breathlessness and general fatigue for 1 week. Chest computed tomography showed no evidence of tumor progression or any new lung lesion. Two-dimensional transthoracic echocardiography demonstrated right atrial and ventricular dilatation, tricuspid regurgitation, and a high trans-tricuspid pressure gradient of 65 mmHg. Despite her percutaneous oxygen saturation being 96% on room air at the time of admission, it worsened rapidly; the patient requiring 8 L/min of oxygen within 4 h. Repeat computed tomography with contrast medium revealed no evidence of pulmonary embolism. The patient developed progressive respiratory failure that was unresponsive to optimal cardio-pulmonary supportive therapy. An autopsy revealed tumorous clusters in pre-capillary lung vessels, whereas the primary lesion had shrunk to the point of almost complete resolution. CONCLUSION: Pulmonary tumor thrombotic microangiopathy occurs not only in patients with advanced and/or uncontrolled cancer but also in those whose primary lesion seems to have been well controlled by medical treatment.

[Multifocal analysis of the bioelectric potential and light sensitivity of the retina in thrombotic microangiopathy associated with malignant arterial hypertension]. / Mul'tifokal'nyi analiz elektricheskogo biopotentsiala i svetovoi chuvstvitel'nosti setchatki pri tromboticheskoi mikroangiopatii, assotsiirovannoi so zlokachestvennoi arterial'noi gipertenziei.

PURPOSE: This study evaluates the function of the retina according to multifocal electroretinography (mfERG) and its light sensitivity according to microperimetry (MP) in patients with thrombotic microangiopathy (TMA) associated with malignant hypertension (MH). MATERIAL AND METHODS: The study analyzed mfERG and MP data of 20 patients (40 eyes) aged 40.4±7.4 years (18 men, 2 women) with MH-associated TMA. In all patients TMA of the kidneys was verified by nephrobiopsy. The control group consisted of 20 healthy individuals (40 eyes) of the appropriate age. RESULTS AND DISCUSSION: A statistically significant decrease in the response density of P1 mfERG (nV/deg2) of the central retinal zone (0-27.7°) was found in study patients in comparison with the control group (p<0.05), differences in the latency of P1 mfERG (ms) were statistically insignificant (p>0.05). Analysis of MP data in study patients revealed a statistically significant decrease in the mean light sensitivity (dB) of the central field of vision (30°) (p<0.05) compared to the control group. A statistically significant correlation was found between the response density of P1 mfERG (nV/deg2) and mean light sensitivity (dB) in the corresponding quadrants of the visual field (p<0.05). A number of statistically significant correlations were found between the indicators of MP and mfERG and some non-ocular clinical manifestations of TMA in MH. CONCLUSION: A statistically significant decrease in the light sensitivity of the central field of vision caused by marked decrease in retinal function, probably of an ischemic nature, is characteristic for MH-associated TMA. In this disease the response density of P1 mfERG (nV/deg2) is a sensitive indicator of impaired retinal function. With the activation of systemic TMA, increase in blood pressure and deterioration of kidney function in MH, the light sensitivity of the eye also decreases.

Proteinuria in thrombotic microangiopathy is associated with partial podocytopathy.

BACKGROUND: Thrombotic microangiopathy (TMA) results in acute kidney injury, but the cause of heavy proteinuria in this disorder is puzzling. The goal of this study was to determine if there were significant effacement of foot processes and CD133-positive hyperplastic podocytes in TMA to explain the proteinuria. METHODS: The study included 12 negative controls (renal parenchyma removed from renal cell carcinoma) and 28 thrombotic microangiopathy due to different etiologies. The percent of foot process effacement was estimated, and proteinuria level was obtained for each TMA case. Both groups of cases were stained for CD133 by immunohistochemical method, and the number of positive CD133 in hyperplastic podocytes was counted and analyzed. RESULTS: Nineteen (19) of 28 (68%) TMA cases had nephrotic range proteinuria (urine protein/creatinine >3). Twenty-one (21) of 28 (75%) TMA cases showed positive CD133 staining in scattered hyperplastic podocytes within Bowman's space but was absent in control cases. The percent of foot process effacement (56 ± 4%) correlated with proteinuria (protein/creatinine ratio 4.4 ± 0.6) (r = 0.46, p = .0237) in TMA group. CONCLUSION: Our data indicate that the proteinuria in TMA can be associated with significant effacement of foot processes. CD133-positive hyperplastic podocytes can be seen in the majority of TMA cases of this cohort, indicating a partial podocytopathy.

Evaluation of Eculizumab Use in Renal Transplant Recipients.

Introduction: Eculizumab is a monoclonal antibody that binds to complement protein C5, inhibiting complement-mediated thrombotic microangiopathy. It is approved for several indications including atypical hemolytic uremic syndrome. Additionally, eculizumab is used off-label for antibody-mediated rejection and C3 glomerulopathy in renal transplant recipients. Due to limited data available, the purpose of this study was to describe the use of eculizumab treatment in renal transplant recipients. Design: This retrospective single-center study evaluated the safety and efficacy of eculizumab for on- and off-label indications in renal transplant recipients. Adult renal transplant recipients receiving at least 1 dose of eculizumab posttransplant between October 2018 and September 2021 were included. The primary outcome evaluated was graft failure in patients treated with eculizumab. Results: Forty-seven patients were included in analysis. The median age at eculizumab initiation was 51 years [IQR 38-60], with 55% being female. Indications for eculizumab included atypical hemolytic uremic syndrome/thrombotic microangiopathy (63.8%), antibody-mediated rejection (27.7%), C3 glomerulopathy (4.3%), and other (4.3%). Graft failure occurred in 10 patients (21.3%) with a median of 2.4 weeks [IQR 0.5-23.3] from transplant to graft failure. At last follow-up (median 56.1 weeks), 44 (93.6%) patients were alive. After eculizumab initiation, renal function improved at 1 week, 1 month, and last follow-up. Conclusion: Eculizumab treatment demonstrated a benefit on graft and patient survival compared to reported incidence in thrombotic microangiopathy and antibody-mediated rejection. Due to the small sample size and retrospective design, further research is warranted to confirm these results.

Pathway-driven rare germline variants associated with transplant-associated thrombotic microangiopathy (TA-TMA).

The significance of rare germline mutations in transplant-associated thrombotic microangiopathy (TA-TMA) is not well studied. We performed a genetic association study in 100 adult TA-TMA patients vs. 98 post-transplant controls after matching by race, sex, and year. We focused on 5 pathways in complement, von Willebrand factor (VWF) function and related proteins, VWF clearance, ADAMTS13 function and related proteins, and endothelial activation (3641variants in 52 genes). In the primary analysis focused on 189 functional rare variants, no differential variant enrichment was observed in any of the pathways; specifically, 29 % TA-TMA and 33 % controls had at least 1 rare complement mutation. In the secondary analysis focused on 37 rare variants predicted to be pathogenic or likely pathogenic by ClinVar, Complement Database, or REVEL in-silico prediction tool, rare variants in the VWF clearance pathway were found to be significantly associated with TA-TMA (p = 0.008). On the gene level, LRP1 was the only one with significantly increased variants in TA-TMA in both analyses (p = 0.025 and 0.015). In conclusion, we did not find a significant association between rare variants in the complement pathway and TA-TMA; however, we discovered a new signal in the VWF clearance pathway driven by the gene LRP1 among likely pathogenic variants.

Microangiopatías trombóticas en niños críticamente enfermos. Registro español MATUCIP / Thrombotic microangiopathies in critically ill children: The MATUCIP registry in Spain

Introducción: Las microangiopatías trombóticas (MAT) son entidades infrecuentes que suelen causar afectación renal, hematológica, neurológica y cardiovascular, con síntomas inespecíficos pero graves. Con la finalidad de mejorar el conocimiento de sus características clínicas, el proceso diagnóstico y el tratamiento en la fase aguda, se ha creado el registro de MAT en las unidades de cuidados intensivos pediátricos (UCIP) de España (Registro MATUCIP). Pacientes y métodos: Estudio observacional, multicéntrico, realizado en 20 UCIP españolas desde enero de 2017 hasta diciembre de 2021 que incluyó niños mayores de 1mes con diagnóstico de MAT y seguimiento hasta el alta de la UCIP. Resultados: Se incluyeron 97 pacientes (51,5% mujeres), con una mediana de edad de 2,6años (RIQ: 1,6-5,7). La clínica inicial fue de tipo gastrointestinal (74,2%), respiratoria (14,4%), cuadro febril (5,2%), neurológica (3,1%) y otras (3,1%). Al ingreso, el 75,3% presentaban anemia hemolítica microangiopática, el 95,9% trombocitopenia y el 94,8% daño renal agudo. Fueron diagnosticados de síndrome hemolítico urémico (SHU) asociado a Escherichia coli productora de toxina Shiga el 57,7%, SHU por Streptococcus pneumoniae el 14,4%, SHU atípico el 15,6%, MAT secundaria el 10,3% y púrpura trombótica trombocitopénica el 2,1%. Desarrollaron hipertensión arterial el 89,7%, manifestaciones digestivas el 49,5%, respiratorias el 22,7%, neurológicas el 25,8% y cardiacas el 12,4%. El 60,8% requirieron depuración extrarrenal y el 2,1%, plasmaféresis. Recibieron eculizumab 20 pacientes. La mediana de estancia en la UCIP fue de 8,5días (RIQ: 5-16,5). Dos niños fallecieron. (AU)

Introduction: Thrombotic microangiopathies (TMA) are rare diseases usually presenting with renal, haematological, neurologic and cardiovascular involvement and nonspecific but severe symptoms. A registry of TMA cases managed in Spanish paediatric intensive care units (the MATUCIP registry) was established with the aim of gaining knowledge on their clinical characteristics, diagnosis and acute-phase treatment. Patients and methods: We conducted a prospective multicentre observational study in 20 paediatric intensive care units (PICUs) in Spain from January 2017 to December 2021 in children aged more than 1month with TMAs, who were followed up through the discharge from the PICU. Results: The sample included 97 patients (51.5% female) with a median age of 2.6years (interquartile range [IQR]: 1.6-5.7). The initial manifestations were gastrointestinal (74.2%), respiratory (14.4%), fever (5.2%), neurologic (3.1%) and other (3.1%). At admission, 75.3% of patients had microangiopathic haemolytic anaemia, 95.9% thrombocytopenia and 94.8% acute kidney injury. Of the total sample, 57.7% of patients received a diagnosis of Shiga toxin-associated haemolytic uraemic syndrome (HUS), 14.4% of Streptococcus pneumoniae-associated HUS, 15.6% of atypical HUS, 10.3% of secondary TMA and 2.1% of thrombotic thrombocytopenic purpura. Eighty-seven patients (89.7%) developed arterial hypertension, and 49.5% gastrointestinal, 22.7% respiratory, 25.8% neurologic and 12.4% cardiac manifestations. Also, 60.8% required renal replacement therapy and 2.1% plasma exchange. Twenty patients received eculizumab. The median PICU stay was 8.5days (IQR: 5-16.5). Two children died. (AU)

Fallo agudo de ventrículo derecho debido a microangiopatía / Right ventricle failure secondary to thrombotic microangiopathy

La microangiopatía trombótica tumoral pulmonar es una enfermedad infrecuente con un diagnóstico de elevada complejidad,que requiere una alta sospecha clínica. La detección precoz es importante debido al mal pronóstico en estadios avanzados.Presentamos el caso de un varón de 39 años ingresado en el hospital para estudio por tos, disnea progresiva, hipertensiónpulmonar y adenopatías abdominales. Durante su ingreso sufrió parada cardiorrespiratoria que no respondió a maniobrasde reanimación cardiopulmonar avanzadas. El examen post mortem mostró hallazgos compatibles con microangiopatíatrombótica tumoral pulmonar secundaria a adenocarcinoma gástrico en estadio avanzado.(AU)

Pulmonary tumour thrombotic microangiopathy is an infrequent disease with a high complex diagnosis that requires highclinical suspicion. Early detection is important because of the poor prognosis in advanced stages. We introduce a case of a39-year-old male admitted in hospital with symptoms of cough, progressively worsening dyspnea, pulmonary hypertensionand abdominal adenopathies. During admission he suffered a cardiac arrest with no response to advanced cardiopulmonaryresuscitation manoeuvres. Post mortem study revealed a pulmonary tumoral thrombotic microangiopathy secondary to gastricadenocarcinoma in advanced stage.(AU)

Eculizumab in the management of drug-induced thrombotic microangiopathy: A scoping review of the literature.

Drug-induced TMA (DI-TMA) is a thrombotic microangiopathy (TMA) caused by certain drugs, usually managed by drug discontinuation and supportive measures. Data on the use of complement-inhibition with eculizumab in DI-TMA is scarce, and its benefit in cases of severe or refractory DI-TMA is unclear. We conducted a comprehensive search in PubMed, Embase and MEDLINE databases (2007-2021). We included articles that reported on DI-TMA patients treated with eculizumab and its clinical outcomes. All other causes of TMA were excluded. We evaluated the outcomes of hematologic recovery, renal recovery, and a composite of both (complete TMA recovery). 35 studies fulfilled our search criteria, which included 69 individual cases of DI-TMA treated with eculizumab. Most cases were secondary to chemotherapeutic agents, and the most implicated drugs were gemcitabine (42/69), carfilzomib (11/69), and bevacizumab (5/69). The median number of eculizumab doses given was 6 (range 1-16). 55/69 (80 %) patients achieved renal recovery, after 28-35 days (5-6 doses). 13/22 (59 %) patients were able to discontinue hemodialysis. 50/68 (74 %) patients achieved complete hematologic recovery after 7-14 days (1-2 doses). 41/68 (60 %) patients met criteria for complete TMA recovery. Eculizumab was safely tolerated in all cases, and appeared to be effective in achieving both hematologic and renal recovery in DI-TMA refractory to drug discontinuation and supportive measures, or with severe manifestations associated with significant morbidity or mortality. Our findings suggest that eculizumab may be considered as a potential treatment for severe or refractory DI-TMA that does not improve after initial management, although larger studies are needed.

Reeling in complement in transplant-associated thrombotic microangiopathy: You're going to need a bigger boat.

Over the last decade there have been numerous advances in both the diagnosis and treatment of transplant-associated thrombotic microangiopathy (TA-TMA). These are largely the result of an improved understanding of complement activation in TA-TMA and the ability to prevent end organ injury and death with timely initiation of complement-blocking therapies. In this article, we review our current understanding of the pathophysiology of TA-TMA, particularly as it pertains to complement activation, endothelial injury, and clinical management. We then review novel complement-blocking therapies that are currently under investigation for use in TA-TMA, as well as discuss special considerations for complement-blocking therapy in hematopoietic stem cell transplant recipients. Through these reviews we aim to answer or at least provide an educated discussion on the most commonly posed TA-TMA management questions and dilemmas.