Risk factors of death or chronic renal replacement therapy requirements in patients with thrombotic microangiopathies without ADAMTS-13 deficiency.

Thrombotic microangiopathy (TMA), characterized by microangiopathic hemolytic anemia, thrombocytopenia, and multisystem organ dysfunction, is a life-threatening disease. Patients with TMA who do not exhibit a severe ADAMTS-13 deficiency (defined as a disintegrin-like and metalloprotease with thrombospondin type 1 motif no. 13 activity ≥10%: TMA-13n) continue to experience elevated mortality rates. This study explores the prognostic indicators for augmented mortality risk or necessitating chronic renal replacement therapy (composite outcome: CO) in TMA-13n patients. We included 42 TMA-13n patients from January 2008 to May 2018. Median age of 41 years and 60% were female. At presentation, 62% required dialysis, and 57% warranted intensive care unit admission. CO was observed in 45% of patients, including a 9-patient mortality subset. Multivariate logistic regression revealed three independent prognostic factors for CO: early administration of eculizumab (median time from hospitalization to eculizumab initiation: 5 days, range 0-19 days; odds ratio [OR], 0.14; 95% confidence interval [CI], 0.02-0.94), presence of neuroradiological lesions (OR, 6.67; 95% CI, 1.12-39.80), and a PLASMIC score ≤4 (OR, 7.39; 95% CI, 1.18-46.11). In conclusion, TMA-13n patients exhibit a heightened risk of CO in the presence of low PLASMIC scores and neuroradiological lesions, while early eculizumab therapy was the only protective factor.

HLA-DR-DQ associations, combined with PLASMIC score, are reliable predictors of acquired thrombotic thrombocytopenic purpura (aTTP) and aid in differentiating aTTP from other thrombotic microangiopathies.

BACKGROUND: Thrombotic microangiopathies (TMA) are a group of disorders with overlapping clinical features that require urgent intervention. Treatment is based on the recognition of the TMA type, which is often challenging. The aim of this study was to identify specific HLA associations with different TMA types to aid rapid diagnosis and appropriate treatment, since the HLA assay can be completed within five hours. METHODS: All 86 consecutive patients who presented to the University of Arkansas for Medical Sciences between May 2013 and January 2021 with a presumptive diagnosis of TMA were included in this study. HLA typing was performed and correlated with other clinical and laboratory studies. RESULTS: In comparison with other types of TMA, patients with acquired thrombotic thrombocytopenic purpura (aTTP) showed increased frequencies of HLA-DRB1*11, HLA-DQB1*03:01/19, HLA-DRB1*08 and HLA-DRB3. Combining the presence of these HLA associations with a PLASMIC score of 6 or more achieved a higher positive predictive value (90%) for identifying aTTP than the PLASMIC score alone (69%). In comparison with other TMA types, patients with aTTP showed decreased frequencies of HLA-DRB4, HLA-DRB1*07, HLA-DQB1*02. The HLA-DRB1*07/DQB1*02 was not observed in any aTTP patients (negative predictive value: 100%), and thus the presence of this haplotype essentially rules out aTTP. Further, HLA-DRB1*11/DQB1*03:01/19 was absent in atypical hemolytic uremic syndrome patients. CONCLUSION: HLA alleles can be used as an adjunct for the rapid assessment of TMA and can help to differentiate it from other primary and secondary forms of TMA, allowing for earlier definitive therapy.

Adult Vitamin B12 Deficiency-Associated Pseudo-Thrombotic Microangiopathy: A Systematic Review of Case Reports.

Cobalamin-deficient thrombotic microangiopathy or vitamin B12 deficiency presenting as pseudo-thrombotic microangiopathy is a rare disorder that can be misdiagnosed as thrombotic thrombocytopenic purpura. Patients with this condition are at risk of receiving unnecessary plasmapheresis with a potential delay in appropriate therapy with vitamin B12 supplementation. There are no established diagnostic criteria for this condition in clinical practice. We performed a systematic review of case reports published between January 2018 and January 2023 to analyze the clinical characteristics, risk factors, and patterns of laboratory markers to improve the diagnostic criteria for this condition.

Hump-Nosed Viper Bite-Associated Thrombotic Thrombocytopenic Purpura: A Rare Complication.

Thrombotic thrombocytopenic purpura (TTP) is one of the rarely encountered complications of hump-nosed viper bites, which requires early detection and specific management. Hump-nosed viper bites are well known to affect multiple systems, and it is imperative to identify and manage each complication simultaneously. A 48-year-old patient presented to the hospital following a hump-nosed viper bite, where he subsequently developed local necrosis, acute kidney injury (AKI), and TTP. A diagnosis of TTP was made using the PLASMIC score (which refers to the score's seven components: platelet count; combined hemolysis variable; absence of active cancer; absence of stem-cell or solid organ transplant; mean corpuscular volume (MCV); international normalized ratio (INR); and creatinine) and supporting blood picture findings despite the diagnostic difficulties encountered due to the misleadingly normal automated platelet counts. The patient underwent multiple blood transfusions, 12 cycles of hemodialysis, and two cycles of therapeutic plasma exchange, the latter contributing to a significant improvement in his overall clinical and biochemical markers. In this case presentation, we report a rare case of TTP occurring after a hump-nosed viper bite, with the outcome of the report focusing on the diagnostic difficulties and available therapeutic modalities.

Cancer-related thrombotic microangiopathy and disseminated intravascular coagulation in a patient with bone marrow carcinomatosis of unknown primary origin: A case report.

BACKGROUND: Cancer-related thrombotic microangiopathy (CR-TMA) is a rare type of Coombs-negative hemolytic anemia, which is caused by malignancy and has a poor prognosis. CASE: A 76-year-old female was referred to our hospital due to Coombs-negative hemolytic anemia, which was causing fatigue and dyspnea on exertion, accompanied by schistocytosis. A bone marrow examination demonstrated bone marrow carcinomatosis, and the tumor cells were morphologically suspected to be signet-ring cell carcinoma cells. As we failed to find the primary tumor site before the patient died, she was diagnosed with CR-TMA due to bone marrow carcinomatosis of unknown primary origin. Thrombotic thrombocytopenic purpura (TTP) was rapidly ruled out based on her PLASMIC score. In addition, immunohistochemical staining of a clot section of the bone marrow and tumor marker data were useful for narrowing down the likely primary tumor site. CONCLUSION: Although CR-TMA is an extremely rare phenomenon, clinicians who suspect CR-TMA should quickly rule out TTP and decide whether to provide appropriate chemotherapy or plan for palliative care.

Renal Thrombotic Microangiopathy: A Complication of Paediatric Systemic Lupus Erythematosus That Requires Attention.

Systemic lupus erythematosus (SLE) is a multi-system disorder with a variety of clinical presentations. A wide range of renal vascular lesions (VL) is described predominantly in adult patients. The exact prevalence of renal VL in the pediatric SLE (pSLE) population is yet to be determined. A 10-year-old female patient with lupus nephritis (LN) presented with deteriorating kidney function. An exhaustive array of clinical-biochemical and pathological evaluations resulted in a diagnosis of class IV LN with thrombotic microangiopathy (TMA) associated with malignant hypertension and hypocomplementemia. Renal VL is overlooked or underreported in SLE patients, as it is neither accorded much importance in the International Society of Nephrology/Renal Pathology Society (ISN/RPS) classification nor in the activity and chronicity scoring. The TMA lesions in LN patients can be managed following the recently devised PLASMIC score; hence, reporting such VL has therapeutic implications.

The Combination of the Lactate Dehydrogenase/Hemoglobin Ratio with the PLASMIC Score Facilitates Differentiation of TTP from Septic DIC Without Identification of Schistocytes.

In some cases, differentiating thrombotic thrombocytopenic purpura (TTP) from septic disseminated intravascular coagulation (DIC) without measuring ADAMTS13 activity is critical for urgent lifesaving plasma exchange. To investigate whether PLASMIC score without identifying the presence of schistocytes, D-dimer, fibrin/fibrinogen degradation products (FDP), FDP/D-dimer ratio, prothrombin time-international normalized ratio (PT-INR), lactate dehydrogenase (LD), hemoglobin (Hb), and LD/Hb ratio are useful in differentiating patients with TTP from those with septic DIC. Retrospective analysis was conducted on the medical records of the patients with septic DIC (32 patients) or TTP (16 patients). The PLASMIC score and other laboratory measurements all were helpful in differentiating TTP from septic DIC. When dichotomized between high risk (scores 6-7) and intermediate-low risk (scores 0-5), the PLASMIC score predicted TTP with a sensitivity of 75.0% and a specificity of 100%. However, 4 of 16 patients with TTP and 19 of 32 patients with septic DIC showed comparable PLASMIC scores of 4 or 5, making it difficult to distinguish between the two by PLASMIC score alone. Among the measurements examined, the LDH/Hb ratio was the most useful for differentiation. Receiver operating characteristic analysis of the LD/Hb ratio for predicting TTP revealed a cutoff of 53.7 (IU/10 g) (sensitivity 0.94, specificity 0.91). If the LD/Hb ratio was less than 53.7, it was unlikely that the patient had TTP. A combination of the LD/Hb ratio and the PLASMIC score may be useful for distinguishing between TTP and DIC and identifying patients who need rapid plasma exchange or caplacizumab administration.

Thrombotic Microangiopathy and Multiple Organ Failure in Scleroderma Renal Crisis: A Case Report.

This case report can be considered a rare occurrence of scleroderma renal crisis (SRC) presenting with a severe clinical course and multiple organ failure. A patient diagnosed with systemic sclerosis four years earlier was admitted to the hospital because of severe malignant systolic-diastolic arterial hypertension and acute kidney injury (AKI). Exacerbating disease suggested thrombotic microangiopathy (TMA) and the PLASMIC (Platelet count; combined hemoLysis variable; absence of Active cancer; absence of Stem-cell or solid-organ transplant; MCV; INR; Creatinine) score was used in the differential diagnosis. Despite the timely initiation of therapy with ACE inhibitors (ACE-I), the progressive renal failure required hemodialysis treatment, but renal function never recovered. Disease duration, skin involvement, and previous specific pharmacological therapy represented multiple risk factors that determined a clinical course complicated by pericardial tamponade with acute heart failure, acute pancreatitis, and ischemic stroke, with fatal evolution. These complications presented a challenging clinical sequence of events requiring an interdisciplinary course of action. Timely ascertainment of the SRC is important given the possible severe organ involvement as well as mortality. A diagnosis of scleroderma renal crisis should be considered in cases of acute kidney injury associated with known risk factors. Early treatment and collaboration between rheumatology and renal physicians can improve patient outcomes.

Immune Thrombotic Thrombocytopenic Purpura in Elderly Patients: The Roles of PLASMIC and French Scores

Objective: In recent years, new developments have been incorporated into daily practice in the management of immune thrombotic thrombocytopenic purpura (iTTP). In particular, clinical scoring systems could help clinicians with clinical decision-making and early recognition. However, older patients frequently present with more organ involvement and in unusual ways. The ways in which age could affect these clinical prediction scoring systems remain unclear. We evaluated the use of PLASMIC and French scores in patients over 60 years of age. Materials and Methods: We performed a retrospective cross-sectional analysis of patients over 60 years of age with a presumptive diagnosis of iTTP between 2014 and 2022 at 10 centers. We calculated PLASMIC and French scores and compared our data with a single-center analysis of younger patients presenting with thrombotic microangiopathy. Results: Our study included 30 patients over 60 years of age and a control group of 28 patients younger than 60 years. The diagnostic sensitivity and specificity of a French score of ≥1 were lower in older patients compared to the control group (78.9% vs. 100% and 18.2% vs. 57.1%, respectively). The diagnostic sensitivity and specificity of a PLASMIC score of ≥5 were 100% vs. 95% and 27.3% vs. 100% for the study group and control group, respectively. Our study showed a higher mortality rate in older patients compared to the control group (30% vs. 7.1%, p=0.043). Conclusion: For a limited number of patients (n=6), our results showed that rituximab can reduce mortality. Given that the reliability of clinical prediction scores for iTTP in older patients may be lower, more caution must be undertaken in interpreting their results.

Challenges in the diagnosis of thrombotic thrombocytopenic purpura.

INTRODUCTION: Immune-mediated TTP (iTTP) is a rare condition without pathognomonic signs and symptoms. For this reason, the diagnosis of iTTP may be delayed or even missed, with potentially catastrophic consequences. AREAS COVERED: The authors performed an extensive literature review on the diagnosis of iTTP and its challenges combined with their own experience in a referral center for patients with iTTP. EXPERT OPINION: Although a definitive diagnosis of iTTP depends on the ADAMTS13 activity result, timely testing is rarely available at many centers to which patients present. If less complex tests were to become available, they would decrease the chances of late and/or missed diagnoses of iTTP throughout the world. While clinical scores to estimate the likelihood of iTTP exist, they are not well known, and can be misleading if used in the wrong context. Furthermore, the three scoring systems (PLASMIC, Bentley, and French) only moderately correlate with each other, which further complicates the landscape. The existence of these scores and how they should be used in practice is but one opportunity that can be seized through more robust programs to educate nonspecialist clinicians on how to recognize and treat patients with iTTP.

Successful Treatment of Refractory Thrombotic Thrombocytopenic Purpura (TTP) With Caplacizumab: A Case Report.

We report a female patient who presented with generalized weakness, episodes of altered mental status and slurred speech, and a history of systemic lupus erythematosus. Initial investigations showed profound thrombocytopenia and schistocytosis on peripheral blood smear. PLASMIC score was promptly calculated, and plasma exchange with steroids was initiated based on the initial high PLASMIC score. Bone marrow examination showed hypocellular marrow without any other obvious abnormalities. The patient's platelet counts initially improved but had a quick decline, on which, rituximab and subsequently caplacizumab were introduced. The patient was discharged after stabilization with plasma exchange (PLEX) therapy as needed on an outpatient basis.

Potential modifications of the PLASMIC scoring system for predicting thrombotic thrombocytopenic purpura: Sometimes, less is more.

INTRODUCTION: Thrombotic thrombocytopenic purpura (TTP) is a life-threatening occlusive disease of the microcirculation characterized by systemic platelet plugs, organ ischemia, deep thrombocytopenia, and fragmentation of erythrocytes. One of the widely used scoring system to determine the clinical probability of TTP is the PLASMIC scoring system. This study aimed to evaluate the contribution of PLASMIC score modifications to sensitivity and specificity in patients with microangiopathic hemolytic anemia (MAHA) undergoing plasma exchange with a prediagnosis of TTP at our center. MATERIALS AND METHODS: The data of patients who were hospitalized with a previous diagnosis of MAHA and TTP and underwent plasma exchange at Bursa Uludag University, Faculty of Medicine, Department of Hematology between January 2000 and January 2022 were retrospectively analyzed. RESULTS: Overall, 33 patients (including 15 and 18 with and without TTP, respectively) were included in this study. Receiver operating characteristic (ROC) analysis revealed that the area under the curve (AUC) for the original PLASMIC score was 0.985 (95% confidence interval [95% CI]: 0.955-1.000), and AUC for the PLASMIC score without mean corpuscular volume (MCV) was 0.967 (95% CI: 0.910-1.000), which is close to the original AUC. With the removal of MCV from the scoring system, the sensitivity decreased from 100% to 93%, whereas the specificity increased from 33% to 78%. CONCLUSIONS: Based on the results of this validation study, removing MCV from the PLASMIC score led to the categorization of eight non-TTP cases in the low-risk category, and this could avoid unnecessary plasma exchange. However, in our study increasing the specificity was at the expense of the sensitivity by missing one patient with this new scoring system without MCV. Further multicenter studies with large sample sizes are required owing to the fact that different parameters may be effective in TTP prediction among different populations.

A Saudi multicenter experience on therapeutic plasma exchange for patients with thrombotic thrombocytopenic purpura: A call for national registry.

BACKGROUND: The improvement in the clinical care for patients with thrombotic thrombocytopenic purpura (TTP) is evolving, and many efforts are being put to standardize it. Here, we aimed to assess the provided care at a national level and identify deficiencies. METHODS: A national Saudi retrospective descriptive study was carried out at six tertiary referral centers and included all patients who underwent therapeutic plasma exchange (TPE) for the diagnosis of TTP between May 2005, and July 2022. Collected information included demographic data, clinical features on presentation, and the results of laboratory investigations at admission and discharge. In addition, the number of TPE sessions, days till the first session of TPE, usage of immunological agents, and clinical outcomes were all collected. RESULTS: One hundred patients were enrolled, predominantly female (56%). The mean age was 36.8 years. At diagnosis, 53% of patients showed neurological involvement. The mean platelet count at presentation was 21 × 109 /L. All patients had anemia (mean hematocrit 24.2%). Schistocytes were present in the peripheral blood film of all patients. The mean number of TPE rounds was 13 ± 9.3, and the mean days to start TPE since admission for the first episode was 2.5 days. ADAMTS13 level was measured in 48% of patients and was significantly low in 77% of them. Assessing for clinical TTP scores, 83%, 1000%, 64% of eligible patients had an intermediate/high PLASMIC, FRENCH, and Bentley scores, respectively. Caplacizumab was used on only one patient, and rituximab was administered to 37% of patients. A complete response for the first episode was achieved in 78% of patients. The overall mortality rate was 25%. Neither time to TPE, the use of rituximab or steroid affected survival. CONCLUSIONS: Our study shows an excellent response to TPE with a survival rate approximate to the reported international literature. We observed a deficiency in using validated scoring systems in addition to confirming the disease by ADAMTS13 testing. This emphasizes the need for a national registry to facilitate proper diagnosis and management of this rare disorder.

A validation and modification of PLASMIC score by adjusting the criteria of mean corpuscular volume and international normalized ratio.

BACKGROUND: The PLASMIC score was developed for distinguishing thrombotic thrombocytopenic purpura (TTP) from other types of thrombotic microangiopathy. However, two components of the PLASMIC score, mean corpuscular volume (MCV) and international normalized ratio (INR), showed non-significant differences between TTP and non-TTP patients in previous validations. Here, we validate the PLASMIC score and aim to modify it by adjusting the criteria of MCV and INR. MATERIALS AND METHODS: A retrospective validation of suspected TTP patients was performed by reviewing electronic medical records from two medical centers in Taiwan. The performance of different modified types of the PLASMIC score was carried out. RESULTS: Among 50 patients included in the final analysis, 12 were diagnosed with TTP based on deficiency of ADAMTS13 activity and clinical judgement. When stratified by high (score ≥ 6) and low-intermediate risk (score < 6), the positive predictive value (PPV) of the PLASMIC score to predict TTP was 0.45 (95% confidence interval [CI]: 0.29-0.61). The area under curve (AUC) was 0.70 (95% CI: 0.56-0.82). When adjusting the criteria of the PLASMIC score from MCV < 90 fL to MCV ≥ 90 fL, the PPV increased to 0.57 (95% CI: 0.37-0.75). The AUC was 0.75 (95% CI: 0.61-0.87). When adjusting the INR from >1.5 to >1.1, the PPV increased to 0.56 (95% CI: 0.39-0.71). The AUC was 0.81 (95% CI: 0.68-0.90). CONCLUSION: MCV ≥ 90 fL and/or INR > 1.1 might be suitable modifications for PLASMIC score but should be validated in a larger sample size.

Current Intensive Care Management of Thrombotic Thrombocytopenic Purpura: A Case Report and Updated Literature Review.

Thrombotic thrombocytopenic purpura (TTP), caused by severely reduced activity of the von Willebrand factor-cleaving protease ADAMTS13, is a medical emergency with life-threatening complications and a 90% mortality rate if left untreated. It presents a diagnostic challenge given the multiorgan involvement of the cardiovascular, gastrointestinal, and central nervous systems. Furthermore, the well-known full pentad of fever, hemolytic anemia, bleeding associated with thrombocytopenia, neurological signs, and renal disease is often absent in patients with TTP. We present a 51-year-old male adult with TTP. We utilized the PLASMIC scoring system, which predicts the likelihood of ADAMST13 activity in adults with features of thrombotic microangiopathy and thrombocytopenia with high sensitivity and specificity. We further review the literature supporting the expert statement on ICU management of patients with TTP that plasma exchange (PEX) should be initiated within 6 hours of diagnosis with adjunctive glucocorticoids, rituximab, and caplacizumab. If PEX is unavailable, plasma infusion can be started while the patient awaits transfer to a center with PEX capabilities.

Role of the PLASMIC Score in the Management of Thrombotic Thrombocytopenic Purpura.

We report the case of a middle-aged male presenting with fatigue and abdominal pain. Prompt investigations demonstrated microangiopathic hemolytic anemia and thrombocytopenia on a peripheral blood smear. Thrombotic thrombocytopenic purpura was suspected based on the PLASMIC score. The patient significantly improved with therapeutic plasma exchange and prednisone within the next few days. The disintegrin and metalloprotease with a thrombospondin type 1 motif, member 13 levels reduction is a definitive hallmark leading to microvascular thrombosis. However, some medical centers in the United States do not promptly have quick allowance to the levels. Hence, the PLASMIC score becomes imminent in initiating immediate management and preventing life-threatening complications.

Epidermolysis Bullosa Acquisita in a patient with End Stage Renal Disease: Case study.

The clinical presentation of COVID-19 varies from being asymptomatic to developing acute respiratory distress syndrome and multi-organ dysfunction. The diffuse microvascular thrombi in multiple organs seen in the autopsy of COVID-19 patients are similar to that of thrombotic microangiopathy (TMA). TMA is characterised by thrombus formation in the microvasculature with laboratory findings of microangiopathic haemolytic anaemia (MAHA) and thrombocytopenia. A 49-year-old male presented to the Aga Khan University Hospital, Karachi. with fever, diarrhoea, altered level of consciousness, and a positive nasopharyngeal swab for SARS-CoV-2. He developed severe thrombocytopenia, MAHA with 5.8% schistocytes, and worsening renal function on the sixth day of admission. Diagnosis of thrombotic thrombocytopenic purpura (TTP) was established based on PLASMIC score, and he was successfully treated with intravenous (IV) Methylprednisolone, therapeutic plasma exchange and IV Rituximab. The case emphasises the need to keep TTP in the differential diagnosis when a patient with COVID-19 develops severe thrombocytopenia, acute renal failure, or impaired level of consciousness, since prompt diagnosis and treatment is necessary to gain favourable outcome.

COVID-19 and thrombotic thrombocytopenic purpura: A case report.

The clinical presentation of COVID-19 varies from being asymptomatic to developing acute respiratory distress syndrome and multi-organ dysfunction. The diffuse microvascular thrombi in multiple organs seen in the autopsy of COVID-19 patients are similar to that of thrombotic microangiopathy (TMA). TMA is characterised by thrombus formation in the microvasculature with laboratory findings of microangiopathic haemolytic anaemia (MAHA) and thrombocytopenia. A 49-year-old male presented to the Aga Khan University Hospital, Karachi. with fever, diarrhoea, altered level of consciousness, and a positive nasopharyngeal swab for SARS-CoV-2. He developed severe thrombocytopenia, MAHA with 5.8% schistocytes, and worsening renal function on the sixth day of admission. Diagnosis of thrombotic thrombocytopenic purpura (TTP) was established based on PLASMIC score, and he was successfully treated with intravenous (IV) Methylprednisolone, therapeutic plasma exchange and IV Rituximab. The case emphasises the need to keep TTP in the differential diagnosis when a patient with COVID-19 develops severe thrombocytopenia, acute renal failure, or impaired level of consciousness, since prompt diagnosis and treatment is necessary to gain favourable outcome.

Validating lactate dehydrogenase (LDH) as a component of the PLASMIC predictive tool (PLASMIC-LDH).

Background: The PLASMIC score is a convenient tool for predicting ADAMTS13 activity of <10%. Lactate dehydrogenase (LDH) is widely used as a marker of haemolysis in thrombotic thrombocytopenic purpura (TTP) monitoring, and could be used as a replacement marker for lysis. We aimed to validate the PLASMIC score in a multi-centre Asia Pacific region, and to explore whether LDH could be used as a replacement marker for lysis. Methods: Records of patients with thrombotic microangiopathy (TMA) were reviewed. Patients' ADAMTS13 activity levels were obtained, along with clinical/laboratory findings relevant to the PLASMIC score. Both PLASMIC scores and PLASMIC-LDH scores, in which LDH replaced traditional lysis markers, were calculated. We generated a receiver operator characteristics (ROC) curve and compared the area under the curve values (AUC) to determine the predictive ability of each score. Results: 46 patients fulfilled the inclusion criteria, of which 34 had ADAMTS13 activity levels of <10%. When the patients were divided into intermediate-to-high risk (scores 5‒7) and low risk (scores 0‒4), the PLASMIC score showed a sensitivity of 97.1% and specificity of 58.3%, with a positive predictive value (PPV) of 86.8% and negative predictive value (NPV) of 87.5%. The PLASMIC-LDH score had a sensitivity of 97.1% and specificity of 33.3%, with a PPV of 80.5% and NPV of 80.0%. Conclusion: Our study validated the utility of the PLASMIC score, and demonstrated PLASMIC-LDH as a reasonable alternative in the absence of traditional lysis markers, to help identify high-risk patients for treatment via plasma exchange.

The perfect storm: Thrombotic thrombocytopenic purpura (TTP) associated with COVID-19, a clinical case series and review.

This is a case series of three patients in our hospital system who developed acquired thrombotic thrombocytopenic purpura (aTTP) after testing positive for COVID-19 infection. Two patients had acute COVID-19 infections, and one had COVID-19 IgG antibodies consistent with prior COVID-19 infection. Twelve additional cases of aTTP after COVID-19 infection were found in the literature. COVID-19 creates alterations in the vWF-ADAMTS-13 axis with reduced ADAMTS-13 in acute illness that may lead those patients who are predisposed into fulminant aTTP. Further genetic studies are necessary to uncover why some patients with COVID-19 can have concurrent aTTP. For those with a prior COVID-19 infection, molecular mimicry with autoantibodies to ADAMTS-13 is likely the predominant trigger, but having an underlying predisposition (prior episode of TTP, genetic predisposition to autoimmune conditions, or breast cancer history) creates an environment that could be a possible trigger for aTTP.