Outcome of severe adult thrombotic microangiopathies in the intensive care unit

ST-Segment-Elevation Myocardial Infarction Unmasking Underlying Systemic Lupus Erythematosus or Representing Thrombotic Thrombocytopenic Purpura? Report of a Challenging Case

Thrombotic thrombocytopenic purpura (TTP) is a multisystem disorder that frequently manifests itself with renal and neurological involvements. Cardiac involvement, however, has been rarely reported. In this report, we present a rare case of acquired TTP with acute myocardial infarction (AMI) as the initial manifestation. Although AMI was successfully managed by percutaneous coronary intervention, the patient developed hemolytic anemia, fever, marked thrombocytopenia, oliguria, and renal dysfunction, requiring treatment with plasma exchange and corticosteroids. TTP, albeit extremely rare, should be considered in cases with unexpected thrombocytopenia during acute-phase treatment for AMI as it can be highly lethal if not treated immediately.

Myasthenia gravis exacerbation and myasthenic crisis associated with COVID-19: case series and literature review

BACKGROUND

Myasthenia gravis (MG) is an autoimmune disorder of the neuromuscular junction that can be exacerbated by many viral infections, including COVID-19. The management of MG exacerbations is challenging in this scenario. We report 8 cases of MG exacerbation or myasthenic crisis associated with COVID-19 and discuss prognosis and treatment based on a literature review.

RESULTS

Most patients were female (7/8), with an average age of 47.1 years. Treatment was immunoglobulin (IVIG) in 3 patients, plasma exchange (PLEX) in 2 patients, and adjustment of baseline drugs in 3. In-hospital mortality was 25% and 37.5% in 2-month follow-up.

DISCUSSION

This is the largest case series of MG exacerbation or myasthenic crisis due to COVID-19 to this date. Mortality was considerably higher than in myasthenic crisis of other etiologies. Previous treatment for MG or acute exacerbation treatment did not seem to interfere with prognosis, although sample size was too small to draw definitive conclusions. Further studies are needed to understand the safety and effectiveness of interventions in this setting, particularly of PLEX, IVIG, rituximab, and tocilizumab.

Outcomes in 1096 patients with severe thrombotic thrombocytopenic purpura before the Caplacizumab era

INTRODUCTION

Thrombotic thrombocytopenic purpura (TTP) is a diagnostic and therapeutic emergency. Therapeutic plasma exchange (TPE) combined with immunosuppression has been the cornerstone of the initial management. To produce optimal benefits, emerging treatments must be used against a background of best standard of care. Clarifying current uncertainties is therefore crucial.

METHODS

The objective of this study was to analyze a large high-quality database (Marketscan) of TTP patients managed between 2005 and 2014, in the pre-caplacizumab era, in order to assess the impact of time to first TPE and use of first-line rituximab on mortality, and whether mortality declines over time.

RESULTS

Among the 1096 included patients (median age 46 [IQR 35-55], 70% female), 28.8% received TPE before day 2 in the ICU. Hospital mortality was 7.6% (83 deaths). Mortality was independently associated with older age (hazard ratio [HR], 1.024/year; 95% confidence interval [95%CI], [1.009-1.040]), diagnosis of sepsis (HR, 2.360; 95%CI [1.552-3.588]), and the need for mechanical ventilation (HR, 4.103; 95%CI, [2.749-6.126]). Factors independently associated with lower mortality were TPE at ICU admission (HR, 0.284; 95%CI, [0.112-0.717]), TPE within one day after ICU admission (HR, 0.449; 95%CI, [0.275-0.907]), and early rituximab therapy (HR, 0.229; 95% CI, [0.111-0.471]). Delayed TPE was associated with significantly higher costs.

CONCLUSIONS

Immediate TPE and early rituximab are associated with improved survival in TTP patients. Improved treatments have led to a decline in mortality over time, and alternate outcome variables such as the use of hospital resources or longer term outcomes therefore need to be considered.

Sudden coma at the onset of severe refractory thrombotic thrombocytopenic purpura with successful treatment

Most patients develop coma several days after the onset of thrombotic thrombocytopenic purpura (TTP) caused by microvascular occlusion. However, aggravated coma as the first symptom of TTP has rarely been reported. Although plasma exchange (PEX) and steroids have reduced mortality, the prognosis of patients with TTP is still poor. We reported a patient with refractory TTP presenting with aggravated coma on admission. After days of successful PEX, rituximab, and glucocorticoid therapy for clinical remission, the patient regained consciousness and returned to his normal life with a good outcome. Our case highlights that TTP should be considered when coma occurs as the first symptom.

Therapeutic Plasma Exchange: A potential Management Strategy for Critically Ill COVID-19 Patients

In the 5 months since initial reports of COVID-19 came to light, the death toll due to SARS-CoV-2 has rapidly increased. The morbidity and mortality of the infection varies based upon patient age, comorbid conditions, viral load, and the availability of effective treatments. Findings from limited autopsies, clinical observations, and laboratory data suggest that high cytokine levels and a procoagulant state can precipitate acute respiratory distress syndrome and multi-organ dysfunction syndrome in critically ill patients. To complicate matters, comorbidities may affect the response to medical treatments currently in use, all of which are still in trial phase. Therapeutic plasma exchange (TPE) merits consideration in the treatment of critically ill COVID-19 patients and is an avenue for clinical trials to pursue. If efficacious, faster recovery of patients may lead to shorter intensive care unit stays and less time on mechanical ventilation. Herein, we briefly discuss some of the various approaches currently being investigated for the treatment of SARS-CoV-2 with a focus on potential benefits of TPE for selected critically ill patients.

Plasmapheresis in Sepsis-induced Thrombotic Microangiopathy: A Case Series

Introduction

Cytokines and granulocyte elastase produced in sepsis cleave a disintegrin and metalloprotease with thrombospondin type I motif 13 (ADAMTS13) and deplete its levels. By this mechanism, sepsis results in microangiopathic hemolytic anemia (MAHA) with thrombocytopenia. Hence, the hypothesis is that plasmapheresis may help in sepsis-induced thrombotic microangiopathy (sTMA), by removing the factors responsible for low levels of ADAMTS13. In tropical countries like India, the contribution of sepsis to intensive care unit (ICU) mortality is high; and hence, it is essential to look out for newer modalities of sepsis treatment. There is abundant literature on the use of plasmapheresis in sepsis but data on its use in sTMA are limited, thus necessitating further research in this field.

Case description

This case series studies the outcomes of five patients admitted with sTMA in the ICU and attempts to evaluate the effectiveness of plasmapheresis in improving their outcomes. All patients diagnosed with sTMA and treated with plasmapheresis, between January 2016 and August 2018 at our tertiary care center, were selected for the study. The diagnosis of sepsis was based on sepsis-3 definition.

Results

Four different gram-negative organisms were found to have caused MAHA, with the commonest source being either urinary tract infection (UTI) or lower respiratory tract infection. Three of five patients required hemodialysis and two had disseminated intravascular coagulation (DIC). All five had good outcome and recovered well from the acute episode post plasmapheresis.

Discussion

In two of five patients, the initial smear was negative and hence the need for repeated examination of the peripheral blood smear should be kept in mind in cases of sTMAs. The median of the number of plasmapheresis sessions required in sTMA is six, which is lesser than that required for primary thrombotic thrombocytopenic purpura (TTP). Hence, the duration of central line placement and the risk of catheter-related complications are low. Based on the observations made in this case study, further exploratory studies are required to evaluate the efficacy of plasmapheresis in sTMA secondary to tropical infections.

How to cite this article

Upadhya SRS, Mahabala C, Kamat JG, Jeganathan J, Kumar S, Prabhu MV. Plasmapheresis in Sepsis-induced Thrombotic Microangiopathy: A Case Series. Indian J Crit Care Med 2020;24(3):195–199.

Expert statement on the ICU management of patients with thrombotic thrombocytopenic purpura

Thrombotic thrombocytopenic purpura (TTP) is fatal in 90% of patients if left untreated and must be diagnosed early to optimize patient outcomes. However, the very low incidence of TTP is an obstacle to the development of evidence-based clinical practice recommendations, and the very wide variability in survival rates across centers may be partly ascribable to differences in management strategies due to insufficient guidance. We therefore developed an expert statement to provide trustworthy guidance about the management of critically ill patients with TTP. As strong evidence was difficult to find in the literature, consensus building among experts could not be reported for most of the items. This expert statement is timely given the recent advances in the treatment of TTP, such as the use of rituximab and of the recently licensed drug caplacizumab, whose benefits will be maximized if the other components of the management strategy follow a standardized pattern. Finally, unanswered questions are identified as topics of future research on TTP.

Early Differentiation of Shiga Toxin-Associated Hemolytic Uremic Syndrome in Critically Ill Adults With Thrombotic Microangiopathy Syndromes

OBJECTIVES

Thrombotic microangiopathy syndromes are a heterogeneous group of severe diseases that often require ICU admission. Prompt initiation of targeted therapies is required for atypical hemolytic uremic syndrome and thrombotic thrombocytopenic purpura, whereas there is no specific consensus therapy for Shiga toxin-associated hemolytic uremic syndrome. We sought to compare the characteristics of Shiga toxin-associated hemolytic uremic syndrome, atypical hemolytic uremic syndrome, and thrombotic thrombocytopenic purpura patients at admission in the ICU to allow early differentiation of Shiga toxin-associated hemolytic uremic syndrome from other thrombotic microangiopathy syndromes and help to tailor initial treatment.

DESIGN

Retrospective cohort study.

SETTING

Two ICUs part of the French reference center for thrombotic microangiopathy syndromes.

PATIENTS

Adult patients presenting with features of thrombotic microangiopathy syndromes. Other causes than Shiga toxin-associated hemolytic uremic syndrome, atypical hemolytic uremic syndrome, and thrombotic thrombocytopenic purpura were excluded.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

From September 2003 to January 2017, 236 thrombotic microangiopathy syndrome patients were admitted, including 12 Shiga toxin-associated hemolytic uremic syndrome, 21 atypical hemolytic uremic syndrome, and 91 thrombotic thrombocytopenic purpura. Shiga toxin-associated hemolytic uremic syndrome patients were older than other thrombotic microangiopathy syndromes patients (64 yr [interquartile range, 50-72 yr] vs 42 yr [31-54 yr]; p = 0.007) and presented with more frequent digestive symptoms (92% vs 42%; p < 0.001), especially nonbloody diarrhea and vomiting. Biologically, Shiga toxin-associated hemolytic uremic syndrome patients displayed higher fibrinogen (490 mg/dL [460-540 mg/dL] vs 320 mg/dL [240-410 mg/dL]; p = 0.003) and creatinine levels (2.59 mg/dL [2.12-3.42 mg/dL] vs 1.26 mg/dL [0.61-1.90 mg/dL]; p < 0.001), and less marked anemia (hemoglobin level, 9.7 g/dL [8.7-11.9 g/dL] vs 7.7 g/dL [6.3-9.1 g/dL]; p < 0.001). Forty-two percent (n = 5) required renal replacement therapy, and 83% (n = 10) were treated with plasma exchange before the distinction from other thrombotic microangiopathy syndromes could be made.

CONCLUSIONS

Adult Shiga toxin-associated hemolytic uremic syndrome patients are older, present more frequently with digestive symptoms and display higher hemoglobin and fibrinogen levels than other thrombotic microangiopathy syndromes. However, overlap across the three thrombotic microangiopathy syndromes remains substantial, putting forward the need to implement early plasma therapy until thrombotic thrombocytopenic purpura and atypical hemolytic uremic syndrome can be ruled out.

Predictive features of chronic kidney disease in atypical haemolytic uremic syndrome

Chronic kidney disease (CKD) is a frequent and serious complication of atypical haemolytic uremic syndrome (aHUS). We aimed to develop a simple accurate model to predict the risk of renal dysfunction in aHUS based on clinical and biological features available at hospital admission. Renal function at 1-year follow-up, based on an estimated glomerular filtration rate < 60mL/min/1.73m2 as assessed by the Modification of Diet in Renal Disease equation, was used as an indicator of significant CKD. Prospectively collected data from a cohort of 156 aHUS patients who did not receive eculizumab were used to identify predictors of CKD. Covariates associated with renal impairment were identified by multivariate analysis. The model performance was assessed and a scoring system for clinical practice was constructed from the regression coefficient. Multivariate analyses identified three predictors of CKD: a high serum creatinine level, a high mean arterial pressure and a mildly decreased platelet count. The prognostic model had a good discriminative ability (area under the curve = .84). The scoring system ranged from 0 to 5, with corresponding risks of CKD ranging from 18% to 100%. This model accurately predicts development of 1-year CKD in patients with aHUS using clinical and biological features available on admission. After further validation, this model may assist in clinical decision making.

Acute renal failure is prevalent in patients with thrombotic thrombocytopenic purpura associated with low plasma ADAMTS13 activity

BACKGROUND

Among patients with thrombotic microangiopathies, acute kidney injury (AKI) is the hallmark of hemolytic uremic syndrome (HUS) and is largely underestimated in patients with thrombotic thrombocytopenic purpura (TTP).

OBJECTIVE

We sought to report AKI features and outcomes in patients with TTP.

METHODS

We conducted a retrospective study of 92 patients with TTP assessed by low ADAMTS13 activity (< 10%) between 2001 and 2013. A logistic regression identified variables independently associated with AKI.

RESULTS

Among the 92 patients, 54 (58.7%) presented with AKI, including 25 (46.3%) with stage 3 AKI. Fourteen (27.4%) patients had a nephrotic-range proteinuria and 21 (45.6%) had hemoglobinuria. Hematuria and leucocyturia were detected in 19 (41.3%) and 16 patients (36.4%), respectively. Renal replacement therapy (RRT) was required in 14 patients (25.9%). Six months after TTP remission, RRT-free patients had median (IQR) MDRD (Modification of Diet in Renal Disease formula estimating the glomerular filtration rate) of 93 mL min(-1) per 1.73 m(2) (68.8-110) and three patients required long-term dialysis. Mild or moderate chronic renal disease occurred in 23/54 (42.6%) AKI patients. By multivariate analysis, serum level of complement component 3 at admission was the only factor independently associated with AKI (OR per 0.25 unit decrease of C3, 0.85; CI, 1.82-8.33; P = 0.001).

CONCLUSIONS

In patients with TTP, AKI is present in more than half the patients, and half of those will have lasting renal effects. Further studies to better understand the pathophysiology of renal involvement in patients with TTP and to identify a subset of patients with TTP syndrome overlapping HUS are warranted.

Use of therapeutic plasma exchange in children with thrombocytopenia-associated multiple organ failure in the Turkish thrombocytopenia-associated multiple organ failure network

OBJECTIVE

Thrombocytopenia-associated multiple organ failure can lead to high mortality in critically ill children, possibly related to consequences of thrombotic microangiopathy. Plasma exchange therapy may improve thrombotic microangiopathy. The purpose of this observational cohort study is to describe whether there is an association between use of plasma exchange therapy and outcome in the Turkish thrombocytopenia-associated multiple organ failure network.

SETTING-INTERVENTIONS

We performed a retrospective cohort analysis in patients with thrombocytopenia-associated multiple organ failure at three different PICUs comparing those who received plasma exchange (+) plus standard therapies with those who did not receive plasma exchange (-) and only received standard therapies.

RESULTS

Among 42 of the enrolled patients with thrombocytopenia-associated multiple organ failure, all had a primary or secondary sepsis diagnosis. Fifteen received plasma exchange therapy (PE [+] group) and 27 received standard medical treatment without plasma exchange (PE [-] group). The mean age was 17.69 months (8.24-54.22) in the PE (+) group and 13.46 months (6.47-20.55) in the PE (-) group. Age (p = 0.232), gender (p = 0.206), thrombocyte count (p = 0.09), Organ Failure Index score (p = 0.111), and pediatric logistic organ dysfunction score (p = 0.177) at admission were not statistically different between groups. The overall 28-day mortality was higher in the PE (-) group (70.37%) compared with the PE (+) group (26.67%) (univariate p = 0.006; multivariate controlling for pediatric logistic organ dysfunction, Organ Failure Index, Pediatric Risk of Mortality scores, and neurological failure p = 0.048). Length of stay was increased in the PE (+) group (p = 0.004).

CONCLUSIONS

The positive association found between use of plasma exchange therapy and improved survival supports the potential of this therapy in Turkish children with thrombocytopenia-associated multiple organ failure. The positive, although less so, associated treatment effect observed after controlling for illness severity provides further rationale for performing a randomized controlled trial in the pediatric Turkish thrombocytopenia-associated multiple organ failure network. Sample size calculations call for a 100-patient trial with a pre hoc interim analysis after enrollment of 50 patients with thrombocytopenia-associated multiple organ failure.

Clinical features of critically ill patients with Shiga toxin-induced hemolytic uremic syndrome

OBJECTIVE

In Spring 2011, an unprecedented outbreak of Shiga toxin-producing Escherichia coli serotype O104:H4-associated hemolytic uremic syndrome occurred in Northern Germany. The aim of this study was to describe the clinical characteristics, treatments, and outcomes of critically ill patients with Shiga toxin-producing E. coli-associated hemolytic uremic syndrome during this outbreak.

DESIGN, SETTING, AND PATIENTS

Multicenter, retrospective, observational study of critically ill adult patients with Shiga toxin-producing E. coli-associated hemolytic uremic syndrome in six hospitals in Hamburg, Germany, between May 2011 and August 2011.

MEASUREMENTS AND MAIN RESULTS

During the study period, 106 patients with Shiga toxin-producing E. coli-associated hemolytic uremic syndrome were admitted to eight ICUs. The median age was 40 years (range, 18-83) with a female:male ratio of 3:1. The median time from onset of clinical symptoms to hospital admission was 3 days and from hospital to ICU admission an additional 3 days. A total of 101 patients (95.3%) had acute renal failure and 78 (73.6%) required renal replacement therapy. Intubation and mechanical ventilation were required in 38 patients (35.8%) and noninvasive ventilation was required in 17 patients (16.0%). The median duration of invasive ventilation was 7 days (range, 1-32 days) and the median ICU stay was 10 days (range, 1-45 days). Fifty-one patients (48.1%) developed sepsis; of these 51 patients, 27 (25.4%) developed septic shock. Seventy patients (66.0%) developed severe neurological symptoms. Ninety-seven patients (91.5%) were treated with plasma exchange and 50 patients (47.2%) received eculizumab (monoclonal anti-C5 antibody). The mortality rate was 4.7%. Mild residual neurological symptoms were present in 21.7% of patients at ICU discharge, and no patient required renal replacement therapy 6 months after ICU admission.

CONCLUSIONS

During the 2011 Shiga toxin-producing E. coli-associated hemolytic uremic syndrome outbreak in Germany, critical illness developed rapidly after hospital admission, often in young women. The infection was associated with severe neurological and renal symptoms, requiring mechanical ventilation and renal replacement therapy in a substantial proportion of patients. Overall, recovery was much better than expected.

Plasma exchange therapy for thrombotic microangiopathies

Thrombotic microangiopathies (TMAs) are syndromes associated with thrombocytopenia and multiple organ failure. Plasma exchange is a proven therapy for primary TMA such as thrombotic thrombocytopenic purpura (TTP). There is growing evidence that plasma exchange therapy might also facilitate resolution of organ dysfunction and improve outcomes for secondary TMAs such as disseminated intravascular coagulation (DIC) and systemic inflammation-induced TTP. In this review, we survey the current available evidence and practice of plasma exchange therapy for TMAs.

Coma in thrombotic thrombocytopenic purpura

Thrombotic thrombocytopenic purpura (TTP) is characterised by a thrombotic, haemolytic microangiopathy leading to microvascular occlusion, haemolysis and ischaemic dysfunction of various organs including the brain. TTP may present with a variety of neurological symptoms, including headache, focal deficits, seizures and coma. The authors describe a 55-year-old man presenting with abdominal pain and rapidly progressive deterioration into coma without focal neurological deficits or seizures. A concomitant, transient, rapid increase in blood pressure raised the suspicion of a hypertensive crisis. Yet, our patient did not improve after vigorous treatment with antihypertensives. Brain imaging excluded a hypertensive leucoencephalopathy. Despite the absence of a disintegrin and metalloproteinase with a thrombospondin type 1 motif member 13 (ADAMTS13) deficiency, the diagnosis idiopathic TTP was made after excluding secondary causes of TTP. Upon treatment with plasma exchange, corticosteroids and vincristin our patient gradually improved. On discharge to a rehabilitation centre he was awake and alert, had minor cognitive deficits and a mild proximal tetraparesis consistent with a critical illness poly(neuro)myopathy.

Thrombotic thrombocytopenic purpura and systemic lupus erythematosus: successful management of a rare presentation

Thrombotic thrombocytopenic purpura (TTP) and systemic lupus erythematosus (SLE) very rarely present simultaneously and pose a diagnostic and therapeutic dilemma to the critical care team. Prompt diagnosis and management with plasma exchange and immunosuppression is life-saving. A patient critically ill with TTP and SLE, successfully managed in the acute period of illness with plasma exchange, steroids and mycophenolate mofetil is described.

CKD in HIV-infected patients other than HIV-associated nephropathy

A spectrum of kidney diseases in HIV-infected patients has been reported both before and after the introduction of highly active antiretroviral therapy (HAART). Kidney syndromes affecting HIV-infected patients include CKD as well as proteinuria, nephrotic syndrome, and acute nephritic syndrome. Thrombotic microangiopathy should be considered in patients with kidney disease and typical clinical characteristics. As the HIV-infected population ages, there is increased concern regarding the incidence of vascular and metabolic disease, leading to an increased burden of CKD. Although HIV-associated nephropathy is still the major cause of nephrotic syndrome in HIV-infected patients, immune complex glomerulonephritis (ICGN) still comprises a substantial proportion of the disease burden, especially in people of European origin. Genetic investigations into the underpinnings of the various histologic expressions of HIV-associated kidney disease hold great promise. The single most important diagnostic test to differentiate various forms of kidney disease in HIV-infected patients is a kidney biopsy. The results of treating kidney disease in HIV-infected patients remain unclear, and properly designed randomized controlled trials of the treatment of ICGN with HAART and other approaches are desperately needed.

Refractory thrombotic thrombocytopenic purpura following influenza vaccination

Thrombotic thrombocytopenic purpura (TTP) is characterised by the systemic microvascular aggregation of platelets causing ischaemia of the brain and other organs. We describe the case of a 54 year-old man who presented with neurological signs, fever, severe thrombocytopenia, microangiopathic haemolytic anaemia and renal failure 5 days after receiving an influenza vaccination. He was diagnosed with acute refractory TTP caused by autoantibody-mediated ADAMTS-13 deficiency. He required stabilisation on the critical care unit before being successfully treated with 3 l plasma exchanges for 21 days and rituximab (MabThera) at a dose of 375 mg x m(-2), given weekly for a total of 4 weeks. Vaccination is an important part of preventative medicine and reduces morbidity and mortality. Only in a few rare cases has vaccination been associated with autoimmune pathology. We could find only one similar case report of thrombotic thrombocytopenic purpura following influenza vaccination. In addition to plasma exchange, rituximab appears to be effective and well tolerated in the treatment of refractory thrombotic thrombocytopenic purpura.

Thrombotic thrombocytopenic purpura associated with severe acute pancreatitis in a context of decreased ADAMTS13 activity: a case report

Thrombotic thrombocytopenic purpura (TTP) is a severe multisystemic microvascular disease defined by the association of hemolytic anemia, thrombocytopenia, acute renal failure, fever, and neurological disorders. The pathophysiology has recently been elucidated by the discovery of a von Willebrand factor-cleaving protease (ADAMTS13) deficiency involved in platelet aggregation and ischemia. The association between TTP and acute pancreatitis (AP) has rarely been reported, described either as a cause or a consequence. The role of ADAMTS13 during AP is still unknown. We describe the case of a 41-year-old woman who developed a TTP, with decreased ADAMTS13 activity, associated with severe AP. Published cases of thrombotic microangiopathy associated with AP are reviewed. The pathophysiology, management, prognostic factors, and rationale for treatment are discussed. AP should be sought in patients with TTP presenting with abdominal pain. On the other hand, TTP should be considered in patients with AP and thrombocytopenia.

[Thrombotic microangiopathies. Incidence, pathogenesis, diagnosis, treatment and prognosis]

INTRODUCTION

The objective of this work was to review current data about the pathophysiology, clinical features, and treatment of thrombotic microangiopathies.

CURRENT KNOWLEDGE

Thrombotic microangiopathies are microvascular occlusive disorders characterized by systemic or intrarenal aggregation of platelets, thrombocytopenia, and mechanical injury to erythrocytes. In thrombotic thrombocytopenic purpura, systemic microvascular aggregation of platelets causes ischemia in the brain and other organs. In the hemolytic-uremic syndrome, platelet-fibrin thrombi occlude predominantly the renal circulation. Thrombotic microangiopathy is a rare disorder whose varied clinical manifestations result from the formation of platelet-rich thrombi within the microvasculature and consequent tissue ischemia. The clinical features are acute renal failure, microangiopathic hemolytic anemia and thrombocytopenia. This diagnosis is of considerable importance because of the possible fulminant clinical course. Some atypical forms may be unrecognized. Plasma exchange is the current reference treatment of thrombotic thrombocytopenic purpura. However, in the light of recent publications, either infusions of concentrates of purified enzyme or more intensive immunosuppressive therapy would be more specific.

Clinical review: specific aspects of acute renal failure in cancer patients

Acute renal failure (ARF) in cancer patients is a dreadful complication that causes substantial morbidity and mortality. Moreover, ARF may preclude optimal cancer treatment by requiring a decrease in chemotherapy dosage or by contraindicating potentially curative treatment. The pathways leading to ARF in cancer patients are common to the development of ARF in other conditions. However, ARF may also develop due to etiologies arising from cancer treatment, such as nephrotoxic chemotherapy agents or the disease itself, including post-renal obstruction, compression or infiltration, and metabolic or immunological mechanisms. This article reviews specific renal disease in cancer patients, providing a comprehensive overview of the causes of ARF in this setting, such as treatment toxicity, acute renal failure in the setting of myeloma or bone marrow transplantation.

Time course of organ dysfunction in thrombotic microangiopathy patients receiving either plasma perfusion or plasma exchange

INTRODUCTION

Few studies have investigated adults with thrombotic microangiopathy (TMA) requiring intensive care unit (ICU) admission, and the treatment remains controversial.

OBJECTIVE

To describe causes, outcomes, prognostic factors, and daily organ-failure score changes in adults with TMA requiring ICU admission.

DESIGN

A 3-yr single-center cohort study.

PATIENTS

The patients were 36 adults with TMA admitted to a teaching-hospital medical ICU between January 2000 and June 2003.

RESULTS

Of the 36 patients, 22 received plasma infusion and 15 underwent plasma exchange. All patients had anemia and thrombocytopenia at ICU admission, and 13 had neurologic impairment. Median creatinine clearance was 55.2 mL/min (interquartile range, 28.8-75.4). No patient had congenital TMA. Causative factors included microbiologically documented infection in 14 patients, allogeneic transplantation in 7 patients, and concomitant or subsequent systemic disease in 7 patients; 6 patients were human immunodeficiency virus-positive, 5 had drug-induced TMA, 2 were pregnant, and 2 had cancer. In 10 patients, no causative factors were identified. Plasma exchange was associated with a statistically significant decrease in hospital mortality (0 vs. 7 deaths; p < .001). Moreover, daily organ-failure scores were significantly lower in the plasma-exchange group from day 3 to day 9. Patients in the plasma-exchange group received a larger volume of plasma.

CONCLUSION

Plasma exchange may be associated with faster resolution of organ failure and with improved survival for patients with TMA requiring ICU admission.

Les microangiopathies thrombotiques en réanimation

OBJECTIVES

To analyze the clinico-biological manifestations, identify the causes and evaluate the outcome of patients with severe thrombotic microangiopathies admitted in a Tunisian intensive care unit.

METHODS

Retrospective study over a period of 10 years (1995-2004) in an intensive care unit.

RESULTS

Were included in this study 9 cases with a mean age of 29.2+/-9 years (range 15-44 years). Fever was observed in 5 patients, neurological impairment in 5 and digestive manifestations in 6. Haemolytic anaemia, thrombocytopenia and acute renal failure were observed in 100% of the cases. In our study, the aetiologies of thrombotic microangiopathies were: complicated pregnancy in 6 cases, systemic lupus erythematosus in 1 case. In contrast, no aetiology was found in 2 patients. Plasma exchange was performed in 5 patients, while 4 patients received only plasma infusion. After an average stay of 18+/-12.5 days, evolution was marked by the death 3 patients.

CONCLUSION

The incidence of severe thrombotic microangiopathies is rare in Tunisian ICU. The clinical manifestations are not specific. Despite the improvement in the outcome by exogenous plasma supply, thrombotic microangiopathies with severe organ dysfunctions leading to hospitalization in the intensive care unit are associated with a high mortality rate.

Acute myocardial infarction in thrombotic microangiopathies—clinical characteristics, risk factors and outcome

BACKGROUND

Acute myocardial infarction (AMI) has been reported and is associated with poor outcome in the course of thrombotic microangiopathies (TMA). However, data are very limited in regard to the clinical characteristics, risk factors and outcome of AMI during TMA. Furthermore, current AMI definitions based on troponins are more sensitive and specific to detect myocardial injury.

METHODS

We retrospectively analysed 74 consecutive patients with 78 TMA episodes. TMA was defined as platelets below 150 x 10(9)/l, haemolytic anaemia, elevated lactate dehydrogenase (LDH) and increased red cell fragmentation, and AMI as serum troponin I above 1 ng/ml with symptoms of myocardial ischaemia and/or appropriate electrocardiography (ECG) alterations.

RESULTS

AMI occurred in 14 TMA episodes (18%) (9 non- and 5 ST-segment elevation AMI). AMI occurred 5+/-3 days after TMA diagnosis, predominately in clinically suspected thrombotic thrombocytopenic purpura (TTP) as TMA subtype. Independent risk factors for subsequent AMI were TTP (RR 2.2; 95% CI 1.1-5.6), and serum LDH above 1,000 U/l (RR 2.7; 95% CI 1.3-7.2) as well as serum troponin I above 0.20 ng/ml at TMA presentation (RR 13.5; 95% CI 2.6-86.8). LDH above 1,000 U/l together with troponin I above 0.20 ng/ml had a sensitivity of 86% (95% CI 60-96%) and a specificity of 95% (95% CI 86-98%) to predict AMI in the later course of TMA. AMI contributed substantially to morbidity causing left ventricular dysfunction in three of eight survivors and potentially accounted for the death in five of six non-survivors.

CONCLUSIONS

AMI is an early, frequent and severe complication during TMA. AMI occurs especially in TTP, and serum LDH above 1,000 U/l in combination with serum troponin I above 0.20 ng/ml at TMA presentation are excellent predictors of subsequent AMI.

Thrombotic Microangiopathy Syndrome in the ICU

Major studies designed to improve our understanding of the pathophysiology of TMA have been conducted over recent years. This improved knowledge opens up new perspectives for more targeted treatment. However, until these innovative treatments become available, early diagnosis of these diseases is essential in order to rapidly initiate specific treatment, as the interval between diagnosis and initiation of plasma exchange is a decisive element in the prognosis of TTP. Treatment must not be stopped too early or too rapidly and must take into account the various associated factors, especially the presence of infection.