Thrombotic thrombocytopenic purpura

Outcomes of patients with thrombotic thrombocytopenic purpura treated in an intensive care unit

Background Thrombotic thrombocytopenic purpura (TTP) is a multisystem disorder characterized by widespread microthrombosis that can predispose to multiple organ failure. The literature is sparse on the outcomes of critically ill patients with TTP managed in intensive care units (ICUs). We aimed to determine the mortality of ICU patients admitted with TTP and evaluate the predictors of survival. We also compared the incidence of nosocomial infection among those who did or did not receive plasma exchange (PE). Methods We conducted a retrospective study in a tertiary ICU. Two authors screened patients for eligibility from the hospital information system based on peripheral smear reports. Adult critically ill TTP patients managed in ICU were included. Patients with a diagnosis of haemolytic uraemic syndrome, autoimmune causes of haemolysis and pregnancy-related conditions, etc. were excluded. Two authors extracted data from medical charts. No imputation of missing variables was done. Non-parametric statistics were used to report data. Statistical analyses were performed using Stata version 16. Results Of the 535 records that were screened, 33 patients were deemed eligible. Mortality among TTP patients was 14 (42%). The women to men ratio was 7:3. At admission, greater degree of anaemia, thrombocytopenia, and higher lactate dehydrogenase levels were observed in non-survivors compared to survivors (5.4 g/dl [4.8-7.1] v. 7.6 g/dl [6.1-8.9], p=0.05; 17x103 μl v. 21x103 μl, p=0.63; and 2987 (1904-3614) U/L v. 2126 U/L (1941-3319), p=0.71; respectively]. Nineteen (57%) patients had acute kidney injury (AKI), of which 11 survived: 6 recovered completely from renal failure and 5 progressed to end-stage renal disease. Nosocomial infection rates were not different among those receiving and not receiving PE therapy (7 [33%] v. 3 [25%], respectively). Conclusion TTP is more common in women and has a high mortality. Older age, low haemoglobin and higher platelet transfusions are predictors of poor survival. Nosocomial infection rates were similar irrespective of receiving PE therapy.

Development and validation of a prediction model (AHC) for early identification of refractory thrombotic thrombocytopenic purpura using nationally representative data

Immune-mediated thrombotic thrombocytopenic purpura (iTTP) is a rare and life-threatening haematological emergency. Although therapeutic plasma exchange together with corticosteroids achieve successful outcomes, a considerable number of patients remain refractory to this treatment and require early initiation of intensive therapy. However, a method for the early identification of refractory iTTP is not available. To develop and validate a model for predicting the probability of refractory iTTP, a cohort of 265 consecutive iTTP patients from 17 large medical centres was retrospectively identified. The derivation cohort included 94 patients from 11 medical centres. For the validation cohort, we included 40 patients from the other six medical centres using geographical validation. An easy-to-use risk score system was generated, and its performance was assessed using internal and external validation cohorts. In the multivariable logistic analysis of the derivation cohort, three candidate predictors were entered into the final prediction model: age, haemoglobin and creatinine. The prediction model had an area under the curve of 0.886 (95% CI: 0.679-0.974) in the internal validation cohort and 0.862 (95% CI: 0.625-0.999) in the external validation cohort. The calibration plots showed a high agreement between the predicted and observed outcomes. In conclusion, we developed and validated a highly accurate prediction model for the early identification of refractory iTTP. It has the potential to guide tailored therapy and is a step towards more personalized medicine.

Thrombotic Thrombocytopenic Purpura, Heparin-Induced Thrombocytopenia, and Disseminated Intravascular Coagulation

Hemostatic abnormalities are common among critically ill patients and are associated with a high risk of bleeding. The abnormalities range from isolated thrombocytopenia or prolongation of global coagulation assays to complex disease states, such as thrombotic microangiopathic syndromes, and can be associated with a wide range of conditions, including trauma, surgery, acute disease processes, cardiopulmonary bypass, and exposure to drugs and blood products. Prompt identification of underlying causes is important because treatment strategies vary. Moreover, prompt initiation of both supportive and specific treatments is vital to decrease the morbidity and mortality in the intensive care unit.

Postoperative Thrombotic Thrombocytopenic Purpura after Total Hip Arthroplasty: A Case Report and Review of the Literature

Thrombotic thrombocytopenic purpura (TTP) is an uncommon and potentially lethal microangiopathy that carries a >90% mortality rate if not treated urgently and appropriately. Postoperative TTP after orthopaedic procedures is particularly rare with only four case reports existing in the literature. We present the case of postoperative TTP in a 57-year-old female who underwent elective total hip arthroplasty. We believe this case adds to the limited literature surrounding the topic. While rare, TTP after orthopaedic procedures poses a real and potentially fatal condition if not managed appropriately. Therefore, it is essential for orthopaedic surgeons to be cognizant of postoperative TTP for timely diagnosis and treatment.

Correlating S100B with disease course in a case of new onset, acquired thrombotic thrombocytopenic purpura (TTP): Could this be a new predictive biomarker in TTP?

Acute thrombotic thrombocytopenic purpura (TTP) is an aggressive thrombotic microangiopathy that if not treated, can have a 90% mortality rate. Clinical manifestations of this disease include profound thrombocytopenia, hemolytic anemia, and end-organ dysfunction. Neurologic symptoms can occur in 80% of patients and range from mild confusion to coma (Scully et al., Br J Haematol 142:819-826). Here, we present the clinical course of a patient diagnosed with new onset acquired TTP who presented with neurologic changes that waxed and waned during her disease course. In addition to usual clinical and laboratory markers for TTP severity and activity, we also collected and analyzed the protein S100B, an astroglial protein studied as a marker for central nervous system injury and impairment of the blood-brain barrier. Our hypothesis here is that because TTP involves endovascular damage, S100B could function as a biomarker for neurologic dysfunction and ultimately, predict disease activity. As illustrated in this case, our patient's S100B levels did appear to correlate with TTP disease activity and the trajectory of this protein seemed a better predictor of cognitive function. Furthermore, increased S100B velocity seemed to be the earliest indicator of a refractory TTP disease process requiring more intensive plasma exchange (TPE) therapy regimen. Therefore, we would suggest that S100B is a promising predictive biomarker of disease activity in guiding the intensity of TPE therapy for TTP as well as cognitive function.

Using plasma exchange to successfully manage thyrotoxicosis in a patient with possible antithyroid drug-related thrombotic thrombocytopenic purpura

OBJECTIVE

Thrombotic thrombocytopenic purpura (TTP) is a rare disease characterized by microangiopathic hemolytic anemia, thrombocytopenic purpura, neurologic abnormalities, fever, and renal insufficiency. The association or co-existence of thyrotoxicosis or antithyroid drugs with TTP has not been previously reported. Subject and Results. Herein, we present a 54-year-old female patient newly diagnosed with toxic multinodular goiter accompanying with TTP, possibly triggered by either thyrotoxicosis or antithyroid drugs.

CONCLUSIONS

The present report is the first in the literature to demonstrate the co-existence of these two diseases and the use of plasma exchange as a modality to treat both conditions.

Mechanisms of Autoantibody-Induced Pathology

Autoantibodies are frequently observed in healthy individuals. In a minority of these individuals, they lead to manifestation of autoimmune diseases, such as rheumatoid arthritis or Graves' disease. Overall, more than 2.5% of the population is affected by autoantibody-driven autoimmune disease. Pathways leading to autoantibody-induced pathology greatly differ among different diseases, and autoantibodies directed against the same antigen, depending on the targeted epitope, can have diverse effects. To foster knowledge in autoantibody-induced pathology and to encourage development of urgently needed novel therapeutic strategies, we here categorized autoantibodies according to their effects. According to our algorithm, autoantibodies can be classified into the following categories: (1) mimic receptor stimulation, (2) blocking of neural transmission, (3) induction of altered signaling, triggering uncontrolled (4) microthrombosis, (5) cell lysis, (6) neutrophil activation, and (7) induction of inflammation. These mechanisms in relation to disease, as well as principles of autoantibody generation and detection, are reviewed herein.