Abstract

OBJECTIVES One of the treatment modalities that can be used for hyperleukocytosis is leukapheresis. However, the result of studies showing the benefit of early mortality through the use of leukapheresis versus no leukapheresis is still inconclusive. Hence, we aimed to conduct a systematic review with meta-analysis to determine the effect of leukapheresis on early mortality in AML patients with hyperleukocytosis. METHODS We conducted a literature search on five databases (PubMed, EBSCOhost, Scopus, Clinicalkey, and JSTOR) up to October 2021 for studies comparing early mortality outcomes between hyperleukocytosis AML patients treated with leukapheresis versus no leukapheresis. Summary odds ratios (OR) and 95% confidence intervals (CI) were calculated using random-effects models. Heterogeneity tests were presented in I(2) value and publication bias was analyzed using a funnel plot. RESULTS Eleven retrospective cohort studies were eligible based on the inclusion and exclusion criteria. Pooled analysis showed that there was no significant difference in early mortality between patients receiving leukapheresis and not receiving leukapheresis in studies using hyperleukocytosis cutoff of 95,000/mm(3) or 100,000/mm(3) (OR: 1.17; 95% CI: 0.74-1.86; p: 0.50; I(2): 0%). Similarly, studies using hyperleukocytosis cutoff of 50,000/mm(3) also showed no benefits of early mortality (OR: 0.67; 95% CI: 0.43-1.05; p: 0.08; I(2): 0%). Most of the studies used had a moderate risk of bias due to being observational studies. Funnel plot showed an indication of publication bias on studies using hyperleukocytosis cutoff of ≥50,000/mm(3). CONCLUSION The use of leukapheresis does not provide early mortality benefit in adult AML patients with hyperleukocytosis.

Abstract

The efficacy and safety of caplacizumab in individuals with acquired thrombotic thrombocytopenic purpura (aTTP) have been established in the phase 2 TITAN and phase 3 HERCULES trials. Integrated analysis of data from both trials was conducted to increase statistical power for assessing treatment differences in efficacy and safety outcomes. Caplacizumab was associated with a significant reduction in the number of deaths (0 vs 4; P < .05) and a significantly lower incidence of refractory TTP (0 vs 8; P < .05) vs placebo during the treatment period. Consistent with the individual trials, treatment with caplacizumab resulted in a faster time to platelet count response (hazard ratio, 1.65; P < .001), a 72.6% reduction in the proportion of patients with the composite end point of TTP-related death, TTP exacerbation, or occurrence of at least 1 treatment-emergent major thromboembolic event during the treatment period (13.0% vs 47.3%; P < .001), and a 33.3% reduction in the median number of therapeutic plasma exchange days (5.0 vs 7.5 days) vs placebo. No new safety signals were identified; mild mucocutaneous bleeding was the main safety finding. This integrated analysis provided new evidence that caplacizumab prevents mortality and refractory disease in acquired TTP and strengthened individual trial findings, with a confirmed favorable safety and tolerability profile. These trials were registered at www.clinicaltrials.gov as #NCT01151423 and #NCT02553317.

Abstract

INTRODUCTION Activation of the complement system and leukocytes by blood-membrane interactions may further promote arteriosclerosis typically present in patients on lipoprotein apheresis. As clinical data on the hemocompatibility of lipoprotein apheresis are scarce, a controlled clinical study comparing two different types of plasma separation and fractionation membranes used in double filtration lipoprotein apheresis was urgently needed, as its outcome may influence clinical decision-making. METHODS In a prospective, randomized, crossover controlled trial, eight patients on double filtration lipoprotein apheresis were subjected to one treatment with recent polyethersulfone (PES) plasma separation and fractionation membranes and one control treatment using a set of ethylene-vinyl alcohol copolymer (EVAL) membranes. White blood cell (WBC) and platelet (PC) counts, complement factor C5a and thrombin-anti-thrombin III (TAT) concentrations were determined in samples drawn at defined times from different sites of the extracorporeal blood and plasma circuit. RESULTS With a nadir at 25 min, WBC in EVAL decreased to 33.5 ± 10.7 % of baseline compared to 63.8 ± 22.0 % at 20 min in PES (P < 0.001). The maximum C5a levels in venous blood re-entering the patients were measured at 30 min, being 30.0 ± 11.2 µg/L with EVAL and 12.3 ± 9.0 µg/L with PES (P < 0.05). The highest C5a concentrations were found in plasma after the plasma filters (EVAL 56.1 ± 22.0 µg/L at 15 min vs. PES 23.3 ± 15.2 µg/L at 10 min; P < 0.001). PC did not significantly decrease over time with both membrane types, while TAT levels did not rise until the end of the treatment without differences between membranes. Regarding lipoprotein(a) and LDL cholesterol removal, both membrane sets performed equally. CONCLUSION Compared to EVAL, PES membranes cause less leukocyte and complement system activation, the classical parameters of hemocompatibility of extracorporeal treatment procedures, at identical treatment efficacy. Better hemocompatibility may avoid inflammation-promoting effects through blood-material interactions in patients requiring double-filtration lipoprotein apheresis.

Abstract

OBJECTIVE To review all published cases of the rare association between thrombotic thrombocytopenic purpura (TTP) and Sjögren's syndrome (SS). The authors report an additional case of this unique association. METHODS Systematic review of the literature and a case report. The database were articles published in PubMed/MEDLINE, Web of Science, LILACS, and SciELO, registered from 1966 to August 2020. The DESH terms were "Sjögren's syndrome" and "thrombotic thrombocytopenic purpura," without language limitation. RESULTS Most patients were female (88%), and the age varied from 30 to 75 years old. Concerning the sequence of disease appearance, SS followed by TTP was seen in seven articles, TTP and SS in three, and simultaneous appearance of both diseases in three studies. Primary SS was observed in 16 patients, and secondary SS was detected in two cases: dermatomyositis and rheumatoid arthritis. Anemia was the most common TTP manifestation, followed by thrombocytopenia, fever, consciousness alteration, renal impairment, and schistocytes' appearance on a blood smear. Treatment involved plasmapheresis, plasma exchange, rituximab, glucocorticoid, and cyclophosphamide. A good outcome was noted in most studies; few patients died. CONCLUSIONS TTP is a rare manifestation associated with SS. After the TTP diagnosis, plasmapheresis and/or plasma exchange should be immediately implemented.

Abstract

BACKGROUND Up to 20% of patients with acute myeloid leukemia (AML) present with hyperleukocytosis, usually defined as a white blood cell (WBC) count greater than 100 × 10(9) /L. Given the high early mortality rate, emergent cytoreduction with either leukapheresis, hydroxyurea, or chemotherapy is indicated, but the optimal strategy is unknown. STUDY DESIGN AND METHODS For this systematic review and meta-analysis we searched MEDLINE and EMBASE via Ovid, Scopus, Cochrane Central Register of Controlled Trials (CENTRAL), and Web of Science from inception through March 2020 for multiarm studies comparing early mortality rates of patients with AML treated with leukapheresis and those who were not. The risk ratio (RR) of early death for patients who received leukapheresis vs patients who did not was estimated using a sum of the log-ratio of individual study estimates weighted by sample size. RESULTS Among 13 two-arm, retrospective studies with 1743 patients (486 leukapheresis and 1257 nonleukapheresis patients), leukapheresis did not improve the primary outcome of early mortality compared to treatment strategies in which leukapheresis was not used (RR, 0.88; 95% confidence interval [CI], 0.69-1.13; P = .321) without statistically significant heterogeneity between studies (Cochran's Q, 18; P = .115; I(2) , 33.4%). Patients presenting with clinical leukostasis tended to be more likely to undergo leukapheresis (odds ratio, 2.01; 95% CI, 0.99-4.08; P = .052). CONCLUSION As we did not find evidence of a short-term mortality benefit and considering the associated complications and logistic burden, our results argue against the routine use of leukapheresis for hyperleukocytosis among patients with AML.

Abstract

PURPOSE The pharmacology, pharmacokinetics, efficacy, safety, dosing and administration, and place in therapy of caplacizumab, a novel antibody fragment that inhibits von Willebrand factor, for the treatment of acquired thrombotic thrombocytopenic purpura (TTP) are summarized. SUMMARY Caplacizumab is a humanized anti-von Willebrand factor monoclonal antibody fragment that inhibits the interaction between ultralarge von Willebrand factor multimers and platelets. Caplacizumab is indicated for use in combination with standard-of-care modalities such as plasma exchange and immunosuppressive therapy for the treatment of adults with acquired TTP. By inhibiting von Willebrand factor, caplacizumab offers a new approach to the management of TTP by preventing the development of potentially life-threatening microvascular thrombosis that can occur in the disease process. In a randomized, placebo-controlled phase 3 trial, patients with acquired TTP treated with caplacizumab had more rapid platelet level normalization than placebo users; caplacizumab use also resulted in lower rates of disease recurrence and TTP-related death. The most common adverse events associated with caplacizumab use are bleeding-related events. In a phase 3 trial, serious bleeding-related adverse events were reported in 8 patients (11%) in the caplacizumab group and 1 patient (1%) in the placebo group. Caplacizumab is administered as an 11-mg intravenous loading dose 15 minutes prior to plasma exchange, followed by administration of 11 mg subcutaneously daily after plasma exchange. Once-daily caplacizumab administration can be continued for 30 days after the last plasma exchange. The medication and supplies for administration are provided as a single-use kit; patients should be trained on proper reconstitution and self-administration technique prior to the use of caplacizumab in the ambulatory setting. CONCLUSION Caplacizumab is a first-in-class von Willebrand factor inhibitor approved for the treatment of adults with acquired TTP.

Abstract

BACKGROUND The PLASMIC score was developed to identify patients with thrombotic microangiopathy who are most likely to have immune thrombotic thrombocytopenic purpura (TTP) and benefit from therapeutic plasma exchange (TPE). PLASMIC scores of 0-4, 5, and 6-7 are said to correspond to low, intermediate, and high probability of TTP, respectively. STUDY DESIGN AND METHODS We conducted a systematic review and meta-analysis on the diagnostic accuracy of the PLASMIC score in adults with suspected TTP. We evaluated the sensitivity, specificity, positive predictive value, and negative predictive value (NPV) of PLASMIC score thresholds of ≥5 and ≥6. Study quality was appraised using the QUADAS-2 tool. RESULTS We identified 13 eligible studies, which collectively enrolled 970 patients. The median prevalence of TTP among eligible studies was 35%. The sensitivity and specificity of a PLASMIC score ≥5 was 0.99 (95% confidence interval [CI], 0.91-1.00) and 0.57 (95% CI, 0.41-0.72), respectively. At a prevalence of 35%, the NPV of a PLASMIC score ≥5 was 0.99 (95% CI, 0.92-1.00). A PLASMIC score ≥6 was associated with a sensitivity and specificity of 0.85 (95% CI, 0.67-0.94) and 0.89 (95% CI, 0.81-0.94), respectively. The NPV of a PLASMIC score ≥6 at a prevalence of 35% was 0.92 (95% CI, 0.82-0.97). CONCLUSION A PLASMIC score threshold of ≥5 is associated with high sensitivity and NPV and may be a useful screening tool for identifying patients who are unlikely to have TTP and do not require TPE, though prospective assessment is required. A PLASMIC score <6 appears to have insufficient sensitivity to rule out TTP and the need for TPE.

Abstract

BACKGROUND In acquired thrombotic thrombocytopenic purpura (TTP), an immune-mediated deficiency of the von Willebrand factor-cleaving protease ADAMTS13 allows unrestrained adhesion of von Willebrand factor multimers to platelets and microthrombosis, which result in thrombocytopenia, hemolytic anemia, and tissue ischemia. Caplacizumab, an anti-von Willebrand factor humanized, bivalent variable-domain-only immunoglobulin fragment, inhibits interaction between von Willebrand factor multimers and platelets. METHODS In this double-blind, controlled trial, we randomly assigned 145 patients with TTP to receive caplacizumab (10-mg intravenous loading bolus, followed by 10 mg daily subcutaneously) or placebo during plasma exchange and for 30 days thereafter. The primary outcome was the time to normalization of the platelet count, with discontinuation of daily plasma exchange within 5 days thereafter. Key secondary outcomes included a composite of TTP-related death, recurrence of TTP, or a thromboembolic event during the trial treatment period; recurrence of TTP at any time during the trial; refractory TTP; and normalization of organ-damage markers. RESULTS The median time to normalization of the platelet count was shorter with caplacizumab than with placebo (2.69 days [95% confidence interval {CI}, 1.89 to 2.83] vs. 2.88 days [95% CI, 2.68 to 3.56], P=0.01), and patients who received caplacizumab were 1.55 times as likely to have a normalization of the platelet count as those who received placebo. The percentage of patients with a composite outcome event was 74% lower with caplacizumab than with placebo (12% vs. 49%, P<0.001). The percentage of patients who had a recurrence of TTP at any time during the trial was 67% lower with caplacizumab than with placebo (12% vs. 38%, P<0.001). Refractory disease developed in no patients in the caplacizumab group and in three patients in the placebo group. Patients who received caplacizumab needed less plasma exchange and had a shorter hospitalization than those who received placebo. The most common adverse event was mucocutaneous bleeding, which was reported in 65% of the patients in the caplacizumab group and in 48% in the placebo group. During the trial treatment period, three patients in the placebo group died. One patient in the caplacizumab group died from cerebral ischemia after the end of the treatment period. CONCLUSIONS Among patients with TTP, treatment with caplacizumab was associated with faster normalization of the platelet count; a lower incidence of a composite of TTP-related death, recurrence of TTP, or a thromboembolic event during the treatment period; and a lower rate of recurrence of TTP during the trial than placebo. (Funded by Ablynx; HERCULES ClinicalTrials.gov number, NCT02553317 .).

Abstract

BACKGROUND Acquired thrombotic thrombocytopenic purpura (aTTP) is a rare, life-threatening autoimmune thrombotic microangiopathy. Caplacizumab, an anti-von Willebrand Factor Nanobody((R)) , is effective for treating aTTP episodes and is well tolerated. OBJECTIVES AND METHODS In the phase 3 HERCULES trial (NCT02553317), patients with aTTP received double-blind caplacizumab or placebo during daily therapeutic plasma exchange (TPE) and for ≥30 days thereafter. Patients who experienced an exacerbation while on blinded study drug treatment switched to receive open-label caplacizumab plus re-initiation of daily TPE. Exacerbations were defined as recurrence of disease occurring within 30 days after cessation of daily TPE. RESULTS Thirty-one patients (placebo, n = 28; caplacizumab, n = 3) had an exacerbation during double-blind treatment. Twenty-eight patients switched to open-label caplacizumab (placebo, n = 26; caplacizumab, n = 2); the three others discontinued upon exacerbation. Median time to platelet count response (≥150 x 10(9) /L) was 3.49 days upon receiving caplacizumab. There were no deaths. During open-label treatment, further exacerbation or a major thromboembolic event (vena cava thrombosis) was experienced by one patient (3.6%) each. Consistent with the double-blind phase, the most frequent treatment-emergent adverse events were catheter site hemorrhage (28.6%), headache (21.4%), and epistaxis (17.9%). CONCLUSIONS These results suggest that caplacizumab was efficacious and well tolerated in patients with aTTP who experienced a disease exacerbation during double-blind treatment in HERCULES.

Abstract

BACKGROUND The iron overload disorder hereditary haemochromatosis is most commonly caused by HFE p.Cys282Tyr homozygosity. In the absence of results from any randomised trials, current evidence is insufficient to determine whether individuals with hereditary haemochromatosis and moderately elevated serum ferritin, should undergo iron reduction treatment. This trial aimed to establish whether serum ferritin normalisation in this population improved symptoms and surrogate biomarkers. METHODS This study was a multicentre, participant-blinded, randomised controlled trial done at three centres in Australia. We enrolled people who were homozygous for HFE p.Cys282Tyr, aged between 18 and 70 years, with moderately elevated serum ferritin, defined as 300-1000 mug/L, and raised transferrin saturation. Participants were randomly assigned, via a computer-generated random number, to undergo either iron reduction by erythrocytapheresis (treatment group) or sham treatment by plasmapheresis (control group). Randomisation was stratified by baseline serum ferritin (<600 mug/L or >=600 mug/L), sex, and study site. Erythrocytapheresis and plasmapheresis were done every 3 weeks, the number of procedures and volume of red cells or plasma removed determined on the basis of each patient's haemoglobin, haematocrit, and serum ferritin concentration, as well their height and weight. In the erythrocytapheresis group, the target was to reduce serum ferritin to less than 300 mug/L. The number of procedures for the control group was based on the initial serum ferritin and prediction of decrease in serum ferritin of approximately 120 mug/L per treatment. The primary outcome was patient-reported Modified Fatigue Impact Scale (MFIS) score, measured at baseline and before unblinding. Analyses were by intention to treat, including the safety analysis. The trial is registered with ClinicalTrials.gov, number NCT01631708, and has been completed. FINDINGS Between Aug 15, 2012, and June 9, 2016, 104 participants were randomly assigned to the treatment (n=54) and control (n=50) groups, of whom 94 completed the study (50 in the treatment group and 44 in the control group). Improvement in MFIS score was greater in the treatment group than in the control group (mean difference -6.3, 95% CI -11.1 to -1.4, p=0.013). There was a significant difference in the cognitive subcomponent (-3.6, -5.9 to -1.3, p=0.0030), but not in the physical (-1.90 -4.5 to 0.63, p=0.14) and psychosocial (-0.54, -1.2 to 0.11, p=0.10) subcomponents. No serious adverse events occurred in either group. One participant in the control group had a vasovagal event and 17 participants (14 in the treatment group and three in the control group) had transient symptoms assessed as related to hypovolaemia. Mild citrate reactions were more common in the treatment group (32 events [25%] in 129 procedures) compared with the control group (one event [1%] in 93 procedures). INTERPRETATION To our knowledge, this study is the first to objectively assess the consequences of iron removal in individuals with hereditary haemochromatosis and moderately elevated serum ferritin. Our results suggest that serum ferritin normalisation by iron depletion could be of benefit for all individuals with hereditary haemochromatosis and elevated serum ferritin levels. FUNDING National Health and Medical Research Council (Australia).