Noninfectious complications of hematopoietic cell transplantation.

Noninfectious lung diseases contribute to nonrelapse mortality. They constitute a spectrum of diseases that can affect the parenchyma, airways, or vascular pulmonary components and specifically exclude cardiac and renal causes. The differential diagnoses of these entities differ as a function of time after hematopoietic cell transplantation. Specific diagnosis, prognosis, and optimal treatment remain challenging, although progress has been made in recent decades.

Early Elevation of Complement Factor Ba Is a Predictive Biomarker for Transplant-Associated Thrombotic Microangiopathy.

Transplant-associated thrombotic microangiopathy (TA-TMA) is a fatal complication after allogeneic hematopoietic stem cell transplantation (allo-HSCT). Previous reports suggest that TA-TMA is caused by complement activation by complement-related genetic variants; however, this needs to be verified, especially in adults. Here, we performed a nested case-control study of allo-HSCT-treated adults at a single center. Fifteen TA-TMA patients and 15 non-TA-TMA patients, matched according to the propensity score, were enrolled. Based on a previous report showing an association between complement-related genes and development of TA-TMA, we first sequenced these 17 genes. Both cohorts harbored several genetic variants with rare allele frequencies; however, there was no difference in the percentage of patients in the TA-TMA and non-TA-TMA groups with the rare variants, or in the average number of rare variants per patient. Second, we measured plasma concentrations of complement proteins. Notably, levels of Ba protein on Day 7 following allo-HSCT were abnormally and significantly higher in TA-TMA than in non-TA-TMA cases, suggesting that complement activation via the alternative pathway contributes to TA-TMA. All other parameters, including soluble C5b-9, on Day 7 were similar between the groups. The levels of C3, C4, CH50, and complement factors H and I in the TA-TMA group after Day 28 were significantly lower than those in the non-TA-TMA group. Complement-related genetic variants did not predict TA-TMA development. By contrast, abnormally high levels of Ba on Day 7 did predict development of TA-TMA and non-relapse mortality. Thus, Ba levels on Day 7 after allo-HSCT are a sensitive and prognostic biomarker of TA-TMA.

Clinical characteristics, triggering etiologies, and response of plasmapheresis in thrombotic microangiopathy in Taiwan.

ABSTRACT: Thrombotic microangiopathy (TMA) syndromes are extraordinarily diverse in clinical presentations and etiologies. However, there are still a limited number of large cohort studies focusing on the underlying causes, outcomes, and response to plasmapheresis.A retrospective study was designed to understand trigger etiologies, organ dysfunctions, clinical outcomes, and efficacy of plasmapheresis in patients with TMA. The whole population of Taiwan was set up into 2 cohorts: 875 patients with TMA in the 2006 cohort (2006-2010) and 1352 patients with TMA in the 2011 cohort (2011-2015). One hundred ninety-five patients in the 2006 cohort and 272 patients in the 2011 cohort were under plasmapheresis treatment.The common underlying etiologies were pregnancy, followed by systemic lupus erythematosus, rheumatoid arthritis, transplantation and drugs, which were significantly higher than the control group. Stroke, seizure, arterial thrombosis, vascular stenosis, hypertension, myocardial infarction, and pancreatitis were the main clinical signs and extra-renal involvements. In the multivariate regression analysis, stroke, arterial thrombosis, peripheral arterial disease, and uremia were significantly higher compared with the control group. The mortality rate in TMA under plasmapheresis was significantly higher than all TMA cases (39.33% vs 15.39% in the 2006 cohort and 39.27% vs 15.06% in the 2011 cohort).This study indicated the spectrum of underlying causes, extra-renal characteristics, and the response to plasmapheresis of patients with TMA in Taiwan. Of note, the poor clinical outcomes of plasmapheresis in patients with TMA might highlight the masked underlying etiology or worse disease condition that should be noticed.

Defibrotide in hematopoietic stem cell transplantation: A multicenter survey study of the Spanish Hematopoietic Stem Cell Transplantation Group (GETH).

BACKGROUND: Defibrotide is approved in European Union for the treatment of severe sinusoidal obstruction syndrome (SOS) after HSCT. However, it has also been used for SOS prophylaxis, moderate SOS and in other complications such as transplant-associated thrombotic microangiopathy (TAM). The objective of this study was to evaluate current uses, effectiveness and safety of defibrotide in patients with HSCT. METHODS: This multicenter, retrospective study included patients treated with defibrotide for any indication at 28 HSCT centers of the Grupo Español de Trasplante Hematopoyetico (GETH) including the pediatric subgroup Grupo Español de Trasplante de Medula en Niños (GETMON). RESULTS: Three hundred and eighty eight patients treated with defibrotide between January 2011 and December 2018 were included. 253 patients were children, and 135 patients were adults. In total, 332 transplants were allogeneic, and the remainder were autologous. Main indications for defibrotide use were severe/very severe SOS in 173 patients, SOS prophylaxis in 135 patients, moderate SOS in 41 patients, TAM in six patients and suspected SOS in 33 patients. Overall survival (OS) at day +100 in the SOS prophylaxis group was 89% (95% CI, 87%-91%). In the group of patients with moderate and severe/very severe SOS, the OS at day +100 was 80% (95% CI, 74%-86%) and 62% (95% CI, 59%-65%), respectively (P = .0015). With a longer follow-up, median of 2 years (4 months-7 years), OS was 63% (95% CI, 59%-67%) in the SOS prophylaxis patients. OS for patients with moderate and severe/very severe SOS groups was 53% (95% CI, 47%-61%) and 26% (95% CI, 22%-30%), respectively (P = .006). 191 patients died, and SOS was the main cause of death in 23 patients (12%). CONCLUSIONS: Defibrotide has an acceptable safety profile with an improved response in severe/very severe SOS compared with historical controls, mainly in pediatric patients. Use of defibrotide for prophylaxis may improve prognosis of patients at high risk of complications due to endothelial damage such as those who receive a second transplant. SOS has an important impact on the HSCT long-term survival, as can be concluded from our study.

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.

Clinical Features and Outcome of Thrombotic Microangiopathies: Comparison between Patients with and without Malignancy.

Thrombotic microangiopathy (TMA) is an uncommon complication of cancers, related to the malignancy itself, antineoplastic drugs, or hematopoietic stem cell transplant. It was reported mostly as case series but large data are lacking. We used the large U.S. MarketScan database to compare TMA between patients with and without malignancy. Adult patients hospitalized between 2005 and 2014 with a diagnosis of TMA were included; cancer patients were defined by a diagnosis of cancer within 1 year prior to or during the admission with TMA. Associated inpatient diagnoses, procedures, hospital mortality, and long-term survival were collected. We included 3,227 patients; 617 (19.1%) had cancer (age 54 [44-60] years, 58% female), which was a new diagnosis for 23% of patients. Two-thirds of cancer patients had solid tumors (mostly pancreas, lung, breast, colorectal, and hepatobiliary, half of them metastatic) and one-third had hematological malignancies (lymphoma, acute leukemia, and multiple myeloma); TMA patients with cancer were older, more often men, had more noncancer-related comorbidities, and developed more sepsis and coagulopathy than TMA patients without cancer. Hospital mortality was significantly higher in cancer patients (16.6% vs. 6.1%, p < 0.001) and reached 30% in transplant recipients; malignancy was an independent risk factor for hospital mortality in multivariate analysis and sensitivity analyses excluding patients with metastases or patients who did not undergo plasmapheresis led to similar results. Malignancy was also associated with decreased long-term survival.

Podocyte Involvement in Renal Thrombotic Microangiopathy: A Clinicopathological Study.

BACKGROUND: The current study aimed to evaluate the associations between podocyte injury and clinicopathological features in renal thrombotic microangiopathy (TMA) based on a Chinese cohort, which might be underscored in this disease. METHODS: The clinical, laboratory, and renal histopathological data of patients with renal biopsy-proven TMA from 2000 to 2015 in our institute were collected. Foot process effacement (FPE) was quantified by foot process width (FPW) by electron microscopy. Podocytes in the renal specimens were also detected by stainings for podocyte-specific markers, including Wilms tumor 1 (WT-1), synaptopodin, and podocalyxin. The associations between FPW and clinico-histopathological data were further analyzed. A composite end-point was defined by all-cause death or end-stage renal disease to address the predictive value of FPW. RESULTS: Sixty-three patients with renal biopsy-proven TMA were enrolled. The FPW of renal TMA patients was 1,090 ± 637 nm (range, 572-4,748 nm), which was significantly higher than the normal range in our center (p = 0.005). By immunohistochemistry and immunofluorescence assays, we found decreased expressions of synaptopodin, podocalyxin, and WT-1 and continued stainings of WT-1 in some podocytes without detectable synaptopodin stainings in the areas of sclerotic tufts and cellular crescents. The FPW value was correlated with the serum albumin concentration (rs = -0.281, p = 0.026), proteinuria amount (rs = 0.255, p = 0.047), serum creatinine levels (rs = 0.339, p = 0.007), and eGFR (rs = -0.335, p = 0.007). According to ROC curve analysis, the optimal cutoff level of FPW for predicting the composite end-point was 869 nm. In patients with FPW ≥ 869 nm, FPW levels were further correlated with the severity of mesangiolysis (rs = 0.351, p = 0.033) and glomerulosclerosis (rs = 0.369, p = 0.025) in pathological evaluations. Patients without clinical remission also had higher FPW than those with remission (1,240 ± 793 vs. 925 ± 344 nm, p = 0.013). The multivariate Cox hazard model showed that FPW ≥ 869 nm was an independent risk factor for the composite end-point (hazard ratio: 3.64, 95% CI: 1.37-9.66, p = 0.009). CONCLUSION: The podocyte injury was prevalent and the FPW levels were closely associated with clinicopathological features, especially prognosis, in renal TMA patients.

Clinical usefulness of diagnostic criteria for transplant-associated thrombotic microangiopathy.

One major cause of treatment-related death is transplant-associated thrombotic microangiopathy (TA-TMA). Because of difficulties with diagnosis, many criteria for TA-TMA have been defined. Some patients clinically suspected as TA-TMA have been treated as TA-TMA regardless of TA-TMA criteria fulfillment (clinical-TMA). To examine sensitivities of TA-TMA criteria for clinical-TMA, we retrospectively evaluated 160 patients undergoing allogeneic hematopoietic stem cell transplantation by five major TA-TMA criteria and compared them with clinical-TMA. Cumulative incidences of TA-TMA and non-relapse mortality (NRM) were widely diverse between criteria. Thirty-eight patients fulfilled one or more TA-TMA criteria (total-TMA), and 12 of them fulfilled only one criterion. In patients with total-TMA, thrombocythemia, serum creatinine > 1.5 × baseline, and proteinuria were especially repeatedly observed among TA-TMA criteria. Ninety-two percent of clinical-TMA patients were classified as patients with total-TMA, and high NRM incidences were exhibited in patients with total-TMA even without clinical-TMA. Hematopoietic cell transplant-comorbidity index ≥ 3, nutritional risk index < 83.5, and grade II-IV acute graft-versus-host disease were extracted as independent risk factors for total-TMA. TA-TMA summation criteria that can cover most of clinical-TMA patients and high-risk patients of NRM were useful in clinical settings, and items of TA-TMA criteria previously described might be triggers for applying TA-TMA criteria.

Pulmonary microvascular metastases in cervical carcinoma: A case series.

Pulmonary microvascular tumor embolism (PMTE), pulmonary tumor thrombotic microangiopathy (PTTM), and lymphangitis carcinomatosis (LC) have an intricate pathophysiology and usually occur with cancers of breast, stomach, and lung. Microvascular pulmonary metastases attributable to cervical cancer are a rarity. Clinical presentation and autopsy findings of patients with microvascular pulmonary metastases in cervical cancers were studied with a review of literature. Four patients (mean age of 55.5 years) with carcinoma cervix showed microvascular metastases. Three of whom presented with respiratory symptoms, and the fourth case was unresponsive on presentation. Each patient succumbed to their illness shortly after admission. Autopsy examination performed on each patient depicted varying combination of PMTE, PTTM, and LC, all with squamous histology. This case series highlights the rare association of carcinoma cervix with the aforementioned microvascular phenomena. Besides, it underscores the sequential mechanism of occurrence of microvascular pulmonary metastasis and the associated guarded prognosis.

Thinking Beyond HLH: Clinical Features of Patients with Concurrent Presentation of Hemophagocytic Lymphohistiocytosis and Thrombotic Microangiopathy.

Hemophagocytic lymphohistiocytosis (HLH) is a syndrome of excessive immune system activation driven mainly by high levels of interferon gamma. The clinical presentation of HLH can have considerable overlap with other inflammatory conditions. We present a cohort of patients with therapy refractory HLH referred to our center who were found to have a simultaneous presentation of complement-mediated thrombotic microangiopathy (TMA). Twenty-three patients had therapy refractory HLH (13 primary, 4 EVB-HLH, 6 HLH without known trigger). Sixteen (69.6%) met high-risk TMA criteria. Renal failure requiring renal replacement therapy, severe hypertension, serositis, and gastrointestinal bleeding were documented only in patients with HLH who had concomitant complement-mediated TMA. Patients with HLH and without TMA required ventilator support mainly due to CNS symptoms, while those with HLH and TMA had respiratory failure predominantly associated with pulmonary hypertension, a known presentation of pulmonary TMA. Ten patients received eculizumab for complement-mediated TMA management while being treated for HLH. All patients who received the complement blocker eculizumab in addition to the interferon gamma blocker emapalumab had complete resolution of their TMA and survived. Our observations suggest co-activation of both interferon and complement pathways as a potential culprit in the evolution of thrombotic microangiopathy in patients with inflammatory disorders like refractory HLH and may offer novel therapeutic approaches for these critically ill patients. TMA should be considered in children with HLH and multi-organ failure, as an early institution of a brief course of complement blocking therapy in addition to HLH-targeted therapy may improve clinical outcomes in these patients.

Difference in thrombotic microangiopathy between concurrently and previously diagnosed systemic lupus erythematosus.

BACKGROUND: Thrombotic microangiopathy (TMA) syndromes are potentially life-threatening complications and are defined as integrated syndromes of microangiopathic hemolytic anemia, thrombocytopenia, and organ injury. Systemic lupus erythematosus (SLE) is an autoimmune disease that can affect various organs, including the hematopoietic system. SLE can complicate with TMA and can be categorized into two distinct groups by chronological association: TMA occurring as the initial presentation and leading to a diagnosis of SLE concurrently (TMA-cSLE) or TMA developing in patients previously diagnosed as having SLE (TMA-pSLE). We examined the differences in clinical characteristics, treatment responses, and clinical outcomes between these groups. METHODS: We reviewed data of patients diagnosed as having TMA and SLE at Taipei Veterans General Hospital between 2002 and 2013. We included 29 patients: 8 and 21 in TMA-cSLE and TMA-pSLE groups, respectively. All underwent plasma exchange. Patients' demographic and clinical characteristics, disease activity, and treatment modality were summarized. RESULTS: Overall survival (OS) from SLE or TMA diagnosis was poor for the TMA-cSLE group. Median OS from SLE diagnosis was 2.9 months in the TMA-cSLE group and 103.5 months in the TMA-pSLE group (p < 0.001). Median OS from TMA diagnosis was 2.9 months in the TMA-cSLE group and 10.7 months in the TMA-pSLE group (p = 0.58). Time to TMA remission after treatment appeared longer in the TMA-cSLE group (38.00 vs 10.76 days). Multivariate Cox analysis revealed TMA-cSLE and anti-RNP positivity were independent risk factors for mortality in SLE patients with TMA. CONCLUSION: The occurrence of TMA with SLE is rare, and its vigorous course results in high mortality and morbidity rates. In patients without a history of autoimmune disease, early suspicion of TMA and working-up for SLE under this condition are vital. Early recognition of TMA-cSLE and prompt plasma exchange with upfront immunosuppressive therapies for TMA-cSLE patients or anti-RNP-positive patients may improve their prognosis.

Incidence, Risk Factors for and Outcomes of Transplant-Associated Thrombotic Microangiopathy.

Transplant-associated thrombotic microangiopathy (TA-TMA) is a complication of allogeneic transplantation (allo-HCT). The incidence and risk factors associated with TA-TMA are not well known. A retrospective analysis from the Center for International Blood and Marrow Transplant Research (CIBMTR) was conducted including patients receiving allo-HCT between 2008 and 2016, with the primary objective of evaluating the incidence of TA-TMA. Secondary objectives included identification of risk factors associated with TA-TMA, and the impact of TA-TMA on overall survival and the need for renal replacement therapy (RRT). Among 23,665 allo-HCT recipients, the 3-year cumulative incidence of TA-TMA was 3%. Variables independently-associated with increased incidence of TA-TMA included female sex, prior autologous transplant, primary disease (acute lymphoblastic leukaemia and severe aplastic anaemia), donor type (mismatched or unrelated donor), conditioning intensity (myeloablative), GVHD prophylaxis (sirolimus + calcineurin inhibitor), pre-transplant kidney dysfunction and acute GVHD (time-varying effect). TA-TMA was associated with higher mortality (HR = 3·1, 95% Confidence Interval [CI] = 2·8-16·3) and RRT requirement (HR = 7·1, 95% CI = 5·7-311·6). This study provides epidemiologic data on TA-TMA and its impact on transplant outcomes. Increased awareness of the risk factors will enable providers to be vigilant of this uncommon but serious transplant complication. The results will also provide benchmarking for future study designs and comparisons.

Efficacy and Safety of Eculizumab in the Treatment of Transplant-Associated Thrombotic Microangiopathy: A Systematic Review and Meta-Analysis.

Background: Transplant-associated thrombotic microangiopathy (TA-TMA) is a dangerous and life-threatening complication in patients undergoing hematopoietic stem cell transplantation (HSCT). Eculizumab has been used in the treatment of TA-TMA, and several studies have confirmed the benefit of Eculizumab in patients with TA-TMA. However, the results remain controversial. We conducted a systematic review and meta-analysis to evaluate the efficacy and safety of Eculizumab for TA-TMA. Materials and Methods: We searched PubMed and Embase for studies on the efficacy and safety of Eculizumab in TA-TMA patients. Efficacy outcomes consisted of overall response rate (ORR), complete response rate (CRR), and survival rate at the last follow-up (SR). Safety outcomes were adverse events (AEs), including infection, sepsis, impaired liver function, infusion reactions, and death. Results: A total of 116 patients from six studies were subjected to meta-analysis. The pooled estimates of ORR, CRR, and SR for TA-TMA patients were 71% (95% CI: 58-82%), 32% (95% CI: 11-56%), and 52% (95% CI: 40-65%), respectively. Only one patient presented with a severe rash, and infection was the most common AEs. The main causes of death were infection and GvHD. Conclusion: Current evidence suggests that Eculizumab improves SR and ORR in patients with TA-TMA and that Eculizumab is well tolerated. However, the number of studies is limited, and the findings are based mainly on data from observational studies. Higher quality randomized controlled trials and more extensive prospective cohort studies are needed.

Effects of recombinant thrombomodulin on long-term prognosis after allogeneic hematopoietic stem cell transplantation.

We investigated the effects of early recombinant thrombomodulin (rTM) treatment on long-term prognosis after hematopoietic stem cell transplantation (HSCT). Subjects included 300 patients who underwent allogeneic HSCT (131 in the rTM(+) group and 169 in the rTM(-) group). The control group received heparin or no anti-coagulation therapy. When we examined patients with confirmed complications (day 1-100), the frequencies of acute graft-versus-host disease (aGVHD) and thrombotic microangiopathy (TMA) were significantly lower in the rTM(+) group, while the frequencies of veno-occlusive disease did not show such differences. rTM administration was associated with significant differences in the cumulative incidence of aGVHD (any grade and II-IV grades) and TMA. The cumulative overall survival probability was significantly higher in the rTM(+) group (42.3% versus 26.2%, p = .037). Therefore, some causes of a poor prognosis included aGVHD and TMA. The present findings suggest that rTM plays a preventive role in transplant-related complications, such as aGVHD and TMA, after allogeneic HSCT.

Approaching treatment of transplant-associated thrombotic Microangiopathy from two directions with Eculizumab and transitioning from Tacrolimus to Sirolimus.

BACKGROUND: In the past, conventional treatment strategies for transplant-associated thrombotic microangiopathy (TA-TMA) have not proven to be very effective. Recently, eculizumab which is a humanized monoclonal antibody that works as a terminal complement inhibitor has demonstrated promise in the treatment landscape of TA-TMA. METHODS AND MATERIALS: This was a single-center retrospective analysis of 20 consecutive adult patients with TA-TMA: 10 patients who received conventional therapy and 10 patients who received eculizumab-based therapy. These patients had undergone allogeneic HSCT at MD Anderson Cancer Center between August 2011 and September 2016. RESULTS: When comparing the treatment outcomes in the two cohorts, none of the patients in the conventional therapy group obtained a hematologic or complete response according to our response criteria whereas seven patients in the eculizumab group achieved a hematologic response with one patient achieving a complete response with organ recovery. In addition, overall survival at the end of assessment was 60% in the eculizumab cohort and 30% in the conventional cohort. One major difference in practice at our institution versus previously published studies is the management of immunosuppression. In a majority of patients, tacrolimus was continued or transitioned to sirolimus for GVHD prophylaxis. CONCLUSION: Response rates and survival were improved for patients who were transitioned to sirolimus, so a two-pronged approach of inhibiting complement along with providing an alternative effective immunosuppressive agent may be beneficial in the treatment of early onset TA-TMA.

Intestinal thrombotic microangiopathy: a distinct entity in the spectrum of graft-versus-host disease.

Transplant-associated thrombotic microangiopathy (TA-TMA) is a severe complication of allogeneic hematopoietic cell transplantation (allo-HCT) with multisystem involvement. Cases of TMA in the intestinal vasculature (intestinal TMA/iTMA) have been reported. We hypothesized that iTMA is a distinct entity from TA-TMA. To test this hypothesis, we prospectively recruited allo-HCT recipients with an indication for endoscopy. Among 20 patients, histological features of iTMA, including loss of glands, total denudation of mucosa, apoptosis and detachment of endothelial cells, mucosal hemorrhage, intraluminal fibrin and microthrombi were found in six. Only 2/6 were classified as GVHD/TA-TMA, while the other 4 as GVHD/no TA-TMA. Gastro-intestinal symptoms were similar between the patients with or without iTMA. With a median follow-up of 11.1 (2.1-67.5) months, 1-year overall survival was 22.2% for iTMA, 55% for GVHD and 60% for TA-TMA. On multivariate analysis, independent unfavorable predictors of OS were iTMA (p = 0.048), HLA mismatched donors (p = 0.008) and gastro-intestinal bleeding (p = 0.021). In conclusion, iTMA emerges as a novel distinct entity in patients with GVHD and/or TA-TMA. Distinct histological features may be useful in differential diagnosis of these severe HCT complications. The higher mortality rates of iTMA than TA-TMA highlight the need for further investigation of this condition.

Postsurgical thrombotic microangiopathy: Case series and review of the literature.

OBJECTIVES: Describe the clinical presentation, treatment, and outcomes of postsurgical thrombotic microangiopathy (TMA). METHODS: In this retrospective study, records of individuals diagnosed with TMA developing within 30 days of a surgical procedure at Mayo Clinic from 2000 to 2016 were reviewed. Available literature regarding postsurgical TMA was comparatively reviewed. RESULTS: Twenty patients were diagnosed with TMA developing within 30 (median 6.5, range (1-28)) days) following a procedure. Preceding procedures included orthopedic (n = 4), vascular (n = 4), abdominal (n = 8), thoracic (n = 2), and other (n = 2). Review of the literature identified 65 patients with postsurgical TMA and cardiovascular procedures were the most common preceding surgery. The majority of patients in the current cohort and literature were treated with therapeutic plasma exchange (TPE). Among the evaluable patients in the current cohort, 100% demonstrated response to TPE; however, 25% required the addition of other therapy including eculizumab to maintain a response 80% of patients in the literature demonstrated a response to TPE. CONCLUSIONS: Although rare, early recognition and treatment of postsurgical TMA can lead to good outcomes. More research is necessary to determine the underlying pathophysiology and optimal treatment for postsurgical TMA.

Elevated Systemic Pentraxin-3 Is Associated With Complement Consumption in the Acute Phase of Thrombotic Microangiopathies.

Pentraxin-3 (PTX3) and C-reactive protein (CRP) have been shown to regulate complement activation in vitro, but their role has not been investigated in complement consumption in vivo. Thrombotic microangiopathies (TMA) are often accompanied by complement overactivation and consumption, therefore we analyzed the relation of the systemic pentraxin levels to the complement profile, laboratory parameters and clinical outcome of TMA patients. We determined the PTX3 and CRP levels, complement factor and activation product concentrations in blood samples of 171 subjects with the diagnosis of typical hemolytic uremic syndrome (STEC-HUS) (N = 34), atypical HUS (aHUS) (N = 44), secondary TMA (N = 63), thrombotic thrombocytopenic purpura (TTP) (N = 30) and 69 age-matched healthy individuals. Clinical data, blood count and chemistry were collected from medical records. To determine the in vitro effect of PTX3 on alternative pathway (AP) activation, sheep red blood cell-based hemolytic assay and AP activity ELISA were used. We found that PTX3 levels were elevated in the acute phase of STEC-HUS, aHUS and secondary TMA, whereas PTX3 elevation was exceptional is TTP. Conversely, a significantly higher median CRP was present in all patient groups compared to controls. PTX3, but not CRP was associated with signs of complement consumption in vivo, and PTX3 significantly decreased the AP hemolytic activity in vitro. Our results provide a detailed description of acute phase-TMA patients' complement profile linked to changes in the systemic pentraxin levels that may support further molecular studies on the function of PTX3 in disease pathogenesis and add to the laboratory assessment of complement consumption in TMA.