Convalescent plasma or hyperimmune immunoglobulin for people with COVID-19: a rapid review

BACKGROUND

Convalescent plasma and hyperimmune immunoglobulin may reduce mortality in patients with respiratory virus diseases, and are currently being investigated in trials as a potential therapy for coronavirus disease 2019 (COVID-19). A thorough understanding of the current body of evidence regarding the benefits and risks is required.  OBJECTIVES: To assess whether convalescent plasma or hyperimmune immunoglobulin transfusion is effective and safe in the treatment of people with COVID-19.

SEARCH METHODS

The protocol was pre-published with the Center for Open Science and can be accessed here: osf.io/dwf53  We searched the World Health Organization (WHO) COVID-19 Global Research Database, MEDLINE, Embase, Cochrane COVID-19 Study Register, Centers for Disease Control and Prevention COVID-19 Research Article Database and trials registries to identify ongoing studies and results of completed studies on 23 April 2020 for case-series, cohort, prospectively planned, and randomised controlled trials (RCTs).

SELECTION CRITERIA

We followed standard Cochrane methodology and performed all steps regarding study selection in duplicate by two independent review authors (in contrast to the recommendations of the Cochrane Rapid Reviews Methods Group). We included studies evaluating convalescent plasma or hyperimmune immunoglobulin for people with COVID-19, irrespective of disease severity, age, gender or ethnicity. We excluded studies including populations with other coronavirus diseases (severe acute respiratory syndrome (SARS) or Middle East respiratory syndrome (MERS)) and studies evaluating standard immunoglobulins.

DATA COLLECTION AND ANALYSIS

We followed recommendations of the Cochrane Rapid Reviews Methods Group regarding data extraction and assessment. To assess bias in included studies, we used the assessment criteria tool for observational studies, provided by Cochrane Childhood Cancer. We rated the certainty of evidence using the GRADE approach for the following outcomes: all-cause mortality at hospital discharge, improvement of clinical symptoms (7, 15, and 30 days after transfusion), grade 3 and 4 adverse events, and serious adverse events.  MAIN RESULTS: We included eight studies (seven case-series, one prospectively planned, single-arm intervention study) with 32 participants, and identified a further 48 ongoing studies evaluating convalescent plasma (47 studies) or hyperimmune immunoglobulin (one study), of which 22 are randomised. Overall risk of bias of the eight included studies was high, due to: study design; small number of participants; poor reporting within studies; and varied type of participants with different severities of disease, comorbidities, and types of previous or concurrent treatments, including antivirals, antifungals or antibiotics, corticosteroids, hydroxychloroquine and respiratory support. We rated all outcomes as very low certainty, and we were unable to summarise numerical data in any meaningful way. As we identified case-series studies only, we reported results narratively. Effectiveness of convalescent plasma for people with COVID-19 The following reported outcomes could all be related to the underlying natural history of the disease or other concomitant treatment, rather than convalescent plasma. All-cause mortality at hospital discharge All studies reported mortality. All participants were alive at the end of the reporting period, but not all participants had been discharged from hospital by the end of the study (15 participants discharged, 6 still hospitalised, 11 unclear). Follow-up ranged from 3 days to 37 days post-transfusion. We do not know whether convalescent plasma therapy affects mortality (very low-certainty evidence).  Improvement of clinical symptoms (assessed by respiratory support) Six studies, including 28 participants, reported the level of respiratory support required; most participants required respiratory support at baseline. All studies reported improvement in clinical symptoms in at least some participants. We do not know whether convalescent plasma improves clinical symptoms (very low-certainty evidence). Time to discharge from hospital Six studies reported time to discharge from hospital for at least some participants, which ranged from four to 35 days after convalescent plasma therapy.  Admission on the intensive care unit (ICU) Six studies included patients who were critically ill. At final follow-up the majority of these patients were no longer on the ICU or no longer required mechanical ventilation. Length of stay on the ICU Only one study (1 participant) reported length of stay on the ICU. The individual was discharged from the ICU 11 days after plasma transfusion. Safety of convalescent plasma for people with COVID-19 Grade 3 or 4 adverse events  The studies did not report the grade of adverse events after convalescent plasma transfusion. Two studies reported data relating to participants who had experienced adverse events, that were presumably grade 3 or 4. One case study reported a participant who had moderate fever (38.9 °C). Another study (3 participants) reported a case of severe anaphylactic shock. Four studies reported the absence of moderate or severe adverse events (19 participants). We are very uncertain whether or not convalescent plasma therapy affects the risk of moderate to severe adverse events (very low-certainty evidence). Serious adverse events One study (3 participants) reported one serious adverse event. As described above, this individual had severe anaphylactic shock after receiving convalescent plasma. Six studies reported that no serious adverse events occurred. We are very uncertain whether or not convalescent plasma therapy affects the risk of serious adverse events (very low-certainty evidence).  AUTHORS' CONCLUSIONS: We identified eight studies (seven case-series and one prospectively planned single-arm intervention study) with a total of 32 participants (range 1 to 10). Most studies assessed the risks of the intervention; reporting two adverse events (potentially grade 3 or 4), one of which was a serious adverse event. We are very uncertain whether convalescent plasma is effective for people admitted to hospital with COVID-19 as studies reported results inconsistently, making it difficult to compare results and to draw conclusions. We identified very low-certainty evidence on the effectiveness and safety of convalescent plasma therapy for people with COVID-19; all studies were at high risk of bias and reporting quality was low. No RCTs or controlled non-randomised studies evaluating benefits and harms of convalescent plasma have been completed. There are 47 ongoing studies evaluating convalescent plasma, of which 22 are RCTs, and one trial evaluating hyperimmune immunoglobulin. We will update this review as a living systematic review, based on monthly searches in the above mentioned databases and registries. These updates are likely to show different results to those reported here.

Thrombocytopenia in Surgery and Neuraxial Anesthesia

This is a review of the evidence for the use of different platelet count thresholds prior to invasive procedures and surgery. This review will focus on three procedures that are common in patients with thrombocytopenia-central venous catheter insertion, liver biopsy, and lumbar punctures and epidural catheters-as well as highlighting the lack of evidence for more major surgery. Tunneled or untunneled central venous catheters are low-risk procedures and can be safely performed without any intervention when the platelet count is 20 × 10⁹/L or above. Evidence for their safety is more limited below this threshold, but as bleeding is easily treated, interventions should focus on treating any bleeding that occurs rather than preventative strategies. The available evidence for neuraxial anesthesia is based on very low-quality evidence from observational studies. Based on this evidence, the risk of an epidural hematoma is less than 0.19% (upper limit of 95% confidence interval) for pregnant women undergoing an epidural anesthetic when the platelet count is between 70 and 99 × 10⁹/L. No randomized trials have been performed in children, nor have any randomized trials been performed in major or emergency surgeries.

Interventions for preventing silent cerebral infarcts in people with sickle cell disease

BACKGROUND

Sickle cell disease (SCD) is one of the commonest severe monogenic disorders in the world, due to the inheritance of two abnormal haemoglobin (beta globin) genes. SCD can cause severe pain, significant end-organ damage, pulmonary complications, and premature death. Silent cerebral infarcts are the commonest neurological complication in children and probably adults with SCD. Silent cerebral infarcts also affect academic performance, increase cognitive deficits and may lower intelligence quotient.

OBJECTIVES

To assess the effectiveness of interventions to reduce or prevent silent cerebral infarcts in people with SCD.

SEARCH METHODS

We searched for relevant trials in the Cochrane Library, MEDLINE (from 1946), Embase (from 1974), the Transfusion Evidence Library (from 1980), and ongoing trial databases; all searches current to 14 November 2019. We searched the Cochrane Cystic Fibrosis and Genetic Disorders Group Trials Register: 07 October 2019.

SELECTION CRITERIA

Randomised controlled trials comparing interventions to prevent silent cerebral infarcts in people with SCD. There were no restrictions by outcomes examined, language or publication status.

DATA COLLECTION AND ANALYSIS

We used standard Cochrane methodological procedures.

MAIN RESULTS

We included five trials (660 children or adolescents) published between 1998 and 2016. Four of the five trials were terminated early. The vast majority of participants had the haemoglobin (Hb)SS form of SCD. One trial focused on preventing silent cerebral infarcts or stroke; three trials were for primary stroke prevention and one trial dealt with secondary stroke prevention. Three trials compared the use of regular long-term red blood cell transfusions to standard care. Two of these trials included children with no previous long-term transfusions: one in children with normal transcranial doppler (TCD) velocities; and one in children with abnormal TCD velocities. The third trial included children and adolescents on long-term transfusion. Two trials compared the drug hydroxyurea and phlebotomy to long-term transfusions and iron chelation therapy: one in primary prevention (children), and one in secondary prevention (children and adolescents). The quality of the evidence was moderate to very low across different outcomes according to GRADE methodology. This was due to trials being at high risk of bias because they were unblinded; indirectness (available evidence was only for children with HbSS); and imprecise outcome estimates. Long-term red blood cell transfusions versus standard care Children with no previous long-term transfusions and higher risk of stroke (abnormal TCD velocities or previous history of silent cerebral infarcts) Long-term red blood cell transfusions may reduce the incidence of silent cerebral infarcts in children with abnormal TCD velocities, risk ratio (RR) 0.11 (95% confidence interval (CI) 0.02 to 0.86) (one trial, 124 participants, low-quality evidence); but make little or no difference to the incidence of silent cerebral infarcts in children with previous silent cerebral infarcts on magnetic resonance imaging and normal or conditional TCDs, RR 0.70 (95% CI 0.23 to 2.13) (one trial, 196 participants, low-quality evidence). No deaths were reported in either trial. Long-term red blood cell transfusions may reduce the incidence of: acute chest syndrome, RR 0.24 (95% CI 0.12 to 0.49) (two trials, 326 participants, low-quality evidence); and painful crisis, RR 0.63 (95% CI 0.42 to 0.95) (two trials, 326 participants, low-quality evidence); and probably reduces the incidence of clinical stroke, RR 0.12 (95% CI 0.03 to 0.49) (two trials, 326 participants, moderate-quality evidence). Long-term red blood cell transfusions may improve quality of life in children with previous silent cerebral infarcts (difference estimate -0.54; 95% confidence interval -0.92 to -0.17; one trial; 166 participants), but may have no effect on cognitive function (least squares means: 1.7, 95% CI -1.1 to 4.4) (one trial, 166 participants, low-quality evidence). Transfusions continued versus transfusions halted: children and adolescents with normalised TCD velocities (79 participants; one trial) Continuing red blood cell transfusions may reduce the incidence of silent cerebral infarcts, RR 0.29 (95% CI 0.09 to 0.97 (low-quality evidence). We are very uncertain whether continuing red blood cell transfusions has any effect on all-cause mortality, Peto odds ratio (OR) 8.00 (95% CI 0.16 to 404.12); or clinical stroke, RR 0.22 (95% CI 0.01 to 4.35) (very low-quality evidence). The trial did not report: comparative numbers for SCD-related adverse events; quality of life; or cognitive function. Hydroxyurea and phlebotomy versus transfusions and chelation Primary prevention, children (121 participants; one trial) We are very uncertain whether switching to hydroxyurea and phlebotomy has any effect on: silent cerebral infarcts (no infarcts); all-cause mortality (no deaths); risk of stroke (no strokes); or SCD-related complications, RR 1.52 (95% CI 0.58 to 4.02) (very low-quality evidence). Secondary prevention, children and adolescents with a history of stroke (133 participants; one trial) We are very uncertain whether switching to hydroxyurea and phlebotomy has any effect on: silent cerebral infarcts, Peto OR 7.28 (95% CI 0.14 to 366.91); all-cause mortality, Peto OR 1.02 (95%CI 0.06 to 16.41); or clinical stroke, RR 14.78 (95% CI 0.86 to 253.66) (very low-quality evidence). Switching to hydroxyurea and phlebotomy may increase the risk of SCD-related complications, RR 3.10 (95% CI 1.42 to 6.75) (low-quality evidence). Neither trial reported on quality of life or cognitive function.

AUTHORS' CONCLUSIONS

We identified no trials for preventing silent cerebral infarcts in adults, or in children who do not have HbSS SCD. Long-term red blood cell transfusions may reduce the incidence of silent cerebral infarcts in children with abnormal TCD velocities, but may have little or no effect on children with normal TCD velocities. In children who are at higher risk of stroke and have not had previous long-term transfusions, long-term red blood cell transfusions probably reduce the risk of stroke, and other SCD-related complications (acute chest syndrome and painful crises). In children and adolescents at high risk of stroke whose TCD velocities have normalised, continuing red blood cell transfusions may reduce the risk of silent cerebral infarcts. No treatment duration threshold has been established for stopping transfusions. Switching to hydroxyurea with phlebotomy may increase the risk of silent cerebral infarcts and SCD-related serious adverse events in secondary stroke prevention. All other evidence in this review is of very low-quality.

Interim PET-results for prognosis in adults with Hodgkin lymphoma: a systematic review and meta-analysis of prognostic factor studies

BACKGROUND

Hodgkin lymphoma (HL) is one of the most common haematological malignancies in young adults and, with cure rates of 90%, has become curable for the majority of individuals. Positron emission tomography (PET) is an imaging tool used to monitor a tumour's metabolic activity, stage and progression. Interim PET during chemotherapy has been posited as a prognostic factor in individuals with HL to distinguish between those with a poor prognosis and those with a better prognosis. This distinction is important to inform decision-making on the clinical pathway of individuals with HL.

OBJECTIVES

To determine whether in previously untreated adults with HL receiving first-line therapy, interim PET scan results can distinguish between those with a poor prognosis and those with a better prognosis, and thereby predict survival outcomes in each group.

SEARCH METHODS

We searched MEDLINE, Embase, CENTRAL and conference proceedings up until April 2019. We also searched one trial registry (ClinicalTrials.gov).

SELECTION CRITERIA

We included retrospective and prospective studies evaluating interim PET scans in a minimum of 10 individuals with HL (all stages) undergoing first-line therapy. Interim PET was defined as conducted during therapy (after one, two, three or four treatment cycles). The minimum follow-up period was at least 12 months. We excluded studies if the trial design allowed treatment modification based on the interim PET scan results.

DATA COLLECTION AND ANALYSIS

We developed a data extraction form according to the Checklist for Critical Appraisal and Data Extraction for Systematic Reviews of Prediction Modelling Studies (CHARMS). Two teams of two review authors independently screened the studies, extracted data on overall survival (OS), progression-free survival (PFS) and PET-associated adverse events (AEs), assessed risk of bias (per outcome) according to the Quality in Prognosis Studies (QUIPS) tool, and assessed the certainty of the evidence (GRADE). We contacted investigators to obtain missing information and data.

MAIN RESULTS

Our literature search yielded 11,277 results. In total, we included 23 studies (99 references) with 7335 newly-diagnosed individuals with classic HL (all stages). Participants in 16 studies underwent (interim) PET combined with computed tomography (PET-CT), compared to PET only in the remaining seven studies. The standard chemotherapy regimen included ABVD (16) studies, compared to BEACOPP or other regimens (seven studies). Most studies (N = 21) conducted interim PET scans after two cycles (PET2) of chemotherapy, although PET1, PET3 and PET4 were also reported in some studies. In the meta-analyses, we used PET2 data if available as we wanted to ensure homogeneity between studies. In most studies interim PET scan results were evaluated according to the Deauville 5-point scale (N = 12). Eight studies were not included in meta-analyses due to missing information and/or data; results were reported narratively. For the remaining studies, we pooled the unadjusted hazard ratio (HR). The timing of the outcome measurement was after two or three years (the median follow-up time ranged from 22 to 65 months) in the pooled studies. Eight studies explored the independent prognostic ability of interim PET by adjusting for other established prognostic factors (e.g. disease stage, B symptoms). We did not pool the results because the multivariable analyses adjusted for a different set of factors in each study. Overall survival Twelve (out of 23) studies reported OS. Six of these were assessed as low risk of bias in all of the first four domains of QUIPS (study participation, study attrition, prognostic factor measurement and outcome measurement). The other six studies were assessed as unclear, moderate or high risk of bias in at least one of these four domains. Four studies were assessed as low risk, and eight studies as high risk of bias for the domain other prognostic factors (covariates). Nine studies were assessed as low risk, and three studies as high risk of bias for the domain 'statistical analysis and reporting'. We pooled nine studies with 1802 participants. Participants with HL who have a negative interim PET scan result probably have a large advantage in OS compared to those with a positive interim PET scan result (unadjusted HR 5.09, 95% confidence interval (CI) 2.64 to 9.81, I² = 44%, moderate-certainty evidence). In absolute values, this means that 900 out of 1000 participants with a negative interim PET scan result will probably survive longer than three years compared to 585 (95% CI 356 to 757) out of 1000 participants with a positive result. Adjusted results from two studies also indicate an independent prognostic value of interim PET scan results (moderate-certainty evidence). Progression-free survival Twenty-one studies reported PFS. Eleven out of 21 were assessed as low risk of bias in the first four domains. The remaining were assessed as unclear, moderate or high risk of bias in at least one of the four domains. Eleven studies were assessed as low risk, and ten studies as high risk of bias for the domain other prognostic factors (covariates). Eight studies were assessed as high risk, thirteen as low risk of bias for statistical analysis and reporting. We pooled 14 studies with 2079 participants. Participants who have a negative interim PET scan result may have an advantage in PFS compared to those with a positive interim PET scan result, but the evidence is very uncertain (unadjusted HR 4.90, 95% CI 3.47 to 6.90, I² = 45%, very low-certainty evidence). This means that 850 out of 1000 participants with a negative interim PET scan result may be progression-free longer than three years compared to 451 (95% CI 326 to 569) out of 1000 participants with a positive result. Adjusted results (not pooled) from eight studies also indicate that there may be an independent prognostic value of interim PET scan results (low-certainty evidence). PET-associated adverse events No study measured PET-associated AEs.

AUTHORS' CONCLUSIONS

This review provides moderate-certainty evidence that interim PET scan results predict OS, and very low-certainty evidence that interim PET scan results predict progression-free survival in treated individuals with HL. This evidence is primarily based on unadjusted data. More studies are needed to test the adjusted prognostic ability of interim PET against established prognostic factors.

Caplacizumab treatment for acquired thrombotic thrombocytopenic purpura (HERCULES trial)

CLINICAL QUESTION

In people with acquired thrombotic thrombocytopenic purpura (TTP), does caplacizumab decrease the time to normalisation of the platelet count and the risk of death and complications caused by thrombotic events and organ damage?

EVIDENCE FROM TRIAL

In adults with acquired TTP, caplacizumab decreased the time to normalisation of the platelet count and decreased the risk of TTP-related death and recurrence of TTP.

Prophylactic plasma transfusion for patients without inherited bleeding disorders or anticoagulant use undergoing non-cardiac surgery or invasive procedures

BACKGROUND

In the absence of bleeding, plasma is commonly transfused to people prophylactically to prevent bleeding. In this context, it is transfused before operative or invasive procedures (such as liver biopsy or chest drainage tube insertion) in those considered at increased risk of bleeding, typically defined by abnormalities of laboratory tests of coagulation. As plasma contains procoagulant factors, plasma transfusion may reduce perioperative bleeding risk. This outcome has clinical importance given that perioperative bleeding and blood transfusion have been associated with increased morbidity and mortality. Plasma is expensive, and some countries have experienced issues with blood product shortages, donor pool reliability, and incomplete screening for transmissible infections. Thus, although the benefit of prophylactic plasma transfusion has not been well established, plasma transfusion does carry potentially life-threatening risks.

OBJECTIVES

To determine the clinical effectiveness and safety of prophylactic plasma transfusion for people with coagulation test abnormalities (in the absence of inherited bleeding disorders or use of anticoagulant medication) requiring non-cardiac surgery or invasive procedures.

SEARCH METHODS

We searched for randomised controlled trials (RCTs), without language or publication status restrictions in: Cochrane Central Register of Controlled Trials (CENTRAL; 2017 Issue 7); Ovid MEDLINE (from 1946); Ovid Embase (from 1974); Cumulative Index to Nursing and Allied Health Literature (CINAHL; EBSCOHost) (from 1937); PubMed (e-publications and in-process citations ahead of print only); Transfusion Evidence Library (from 1950); Latin American Caribbean Health Sciences Literature (LILACS) (from 1982); Web of Science: Conference Proceedings Citation Index-Science (CPCI-S) (Thomson Reuters, from 1990); ClinicalTrials.gov; and World Health Organization (WHO) International Clinical Trials Registry Search Platform (ICTRP) to 28 January 2019.

SELECTION CRITERIA

We included RCTs comparing: prophylactic plasma transfusion to placebo, intravenous fluid, or no intervention; prophylactic plasma transfusion to alternative pro-haemostatic agents; or different haemostatic thresholds for prophylactic plasma transfusion. We included participants of any age, and we excluded trials incorporating individuals with previous active bleeding, with inherited bleeding disorders, or taking anticoagulant medication before enrolment.

DATA COLLECTION AND ANALYSIS

We used standard methodological procedures expected by Cochrane.

MAIN RESULTS

We included five trials in this review, all were conducted in high-income countries. Three additional trials are ongoing. One trial compared fresh frozen plasma (FFP) transfusion with no transfusion given. One trial compared FFP or platelet transfusion or both with neither FFP nor platelet transfusion given. One trial compared FFP transfusion with administration of alternative pro-haemostatic agents (factors II, IX, and X followed by VII). One trial compared the use of different transfusion triggers using the international normalised ratio measurement. One trial compared the use of a thromboelastographic-guided transfusion trigger using standard laboratory measurements of coagulation. Four trials enrolled only adults, whereas the fifth trial did not specify participant age. Four trials included only minor procedures that could be performed by the bedside. Only one trial included some participants undergoing major surgical operations. Two trials included only participants in intensive care. Two trials included only participants with liver disease. Three trials did not recruit sufficient participants to meet their pre-calculated sample size. Overall, the quality of evidence was low to very low across different outcomes according to GRADE methodology, due to risk of bias, indirectness, and imprecision. One trial was stopped after recruiting two participants, therefore this review's findings are based on the remaining four trials (234 participants). When plasma transfusion was compared with no transfusion given, we are very uncertain whether there was a difference in 30-day mortality (1 trial comparing FFP or platelet transfusion or both with neither FFP nor platelet transfusion, 72 participants; risk ratio (RR) 0.38, 95% confidence interval (CI) 0.13 to 1.10; very low-quality evidence). We are very uncertain whether there was a difference in major bleeding within 24 hours (1 trial comparing FFP transfusion vs no transfusion, 76 participants; RR 0.33, 95% CI 0.01 to 7.93; very low-quality evidence; 1 trial comparing FFP or platelet transfusion or both with neither FFP nor platelet transfusion, 72 participants; RR 1.59, 95% CI 0.28 to 8.93; very low-quality evidence). We are very uncertain whether there was a difference in the number of blood product transfusions per person (1 trial, 76 participants; study authors reported no difference; very low-quality evidence) or in the number of people requiring transfusion (1 trial comparing FFP or platelet transfusion or both with neither FFP nor platelet transfusion, 72 participants; study authors reported no blood transfusion given; very low-quality evidence) or in the risk of transfusion-related adverse events (acute lung injury) (1 trial, 76 participants; study authors reported no difference; very low-quality evidence). When plasma transfusion was compared with other pro-haemostatic agents, we are very uncertain whether there was a difference in major bleeding (1 trial; 21 participants; no events; very low-quality evidence) or in transfusion-related adverse events (febrile or allergic reactions) (1 trial, 21 participants; RR 9.82, 95% CI 0.59 to 162.24; very low-quality evidence). When different triggers for FFP transfusion were compared, the number of people requiring transfusion may have been reduced (for overall blood products) when a thromboelastographic-guided transfusion trigger was compared with standard laboratory tests (1 trial, 60 participants; RR 0.18, 95% CI 0.08 to 0.39; low-quality evidence). We are very uncertain whether there was a difference in major bleeding (1 trial, 60 participants; RR 0.33, 95% CI 0.01 to 7.87; very low-quality evidence) or in transfusion-related adverse events (allergic reactions) (1 trial; 60 participants; RR 0.33, 95% CI 0.01 to 7.87; very low-quality evidence). Only one trial reported 30-day mortality. No trials reported procedure-related harmful events (excluding bleeding) or quality of life.

AUTHORS' CONCLUSIONS

Review findings show uncertainty for the utility and safety of prophylactic FFP use. This is due to predominantly very low-quality evidence that is available for its use over a range of clinically important outcomes, together with lack of confidence in the wider applicability of study findings, given the paucity or absence of study data in settings such as major body cavity surgery, extensive soft tissue surgery, orthopaedic surgery, or neurosurgery. Therefore, from the limited RCT evidence, we can neither support nor oppose the use of prophylactic FFP in clinical practice.

Multiple drug combinations of bortezomib, lenalidomide, and thalidomide for first-line treatment in adults with transplant-ineligible multiple myeloma: a network meta-analysis

BACKGROUND

Multiple myeloma is a bone marrow-based hematological malignancy accounting for approximately two per cent of cancers. First-line treatment for transplant-ineligible individuals consists of multiple drug combinations of bortezomib (V), lenalidomide (R), or thalidomide (T). However, access to these medicines is restricted in many countries worldwide.

OBJECTIVES

To assess and compare the effectiveness and safety of multiple drug combinations of V, R, and T for adults with newly diagnosed transplant-ineligible multiple myeloma and to inform an application for the inclusion of these medicines into the World Health Organization's (WHO) list of essential medicines.

SEARCH METHODS

We searched CENTRAL and MEDLINE, conference proceedings and study registries on 14 February 2019 for randomised controlled trials (RCTs) comparing multiple drug combinations of V, R and T for adults with newly diagnosed transplant-ineligible multiple myeloma.

SELECTION CRITERIA

We included RCTs comparing combination therapies of V, R, and T, plus melphalan and prednisone (MP) or dexamethasone (D) for first-line treatment of adults with transplant-ineligible multiple myeloma. We excluded trials including adults with relapsed or refractory disease, trials comparing drug therapies to other types of therapy and trials including second-generation novel agents.

DATA COLLECTION AND ANALYSIS

Two review authors independently extracted data and assessed risk of bias of included trials. As effect measures we used hazard ratios (HRs) for overall survival (OS) and progression-free survival (PFS) and risk ratios (RRs) for adverse events. An HR or RR < 1 indicates an advantage for the intervention compared to the main comparator MP. Where available, we extracted quality of life (QoL) data (scores of standardised questionnaires). Results quoted are from network meta-analysis (NMA) unless stated.

MAIN RESULTS

We included 25 studies (148 references) comprising 11,403 participants and 21 treatment regimens. Treatments were differentiated between restricted treatment duration (treatment with a pre-specified amount of cycles) and continuous therapy (treatment administered until disease progression, the person becomes intolerant to the drug, or treatment given for a prolonged period). Continuous therapies are indicated with a "c". Risk of bias was generally high across studies due to the open-label study design. Overall survival (OS) Evidence suggests that treatment with RD (HR 0.63 (95% confidence interval (CI) 0.40 to 0.99), median OS 55.2 months (35.2 to 87.0)); TMP (HR 0.75 (95% CI 0.58 to 0.97), median OS: 46.4 months (35.9 to 60.0)); and VRDc (HR 0.49 (95% CI 0.26 to 0.92), median OS 71.0 months (37.8 to 133.8)) probably increases survival compared to median reported OS of 34.8 months with MP (moderate certainty). Treatment with VMP may result in a large increase in OS, compared to MP (HR 0.70 (95% CI 0.45 to 1.07), median OS 49.7 months (32.5 to 77.3)), low certainty). Progression-free survival (PFS) Treatment withRD (HR 0.65 (95% CI0.44 to 0.96), median PFS: 24.9 months (16.9 to 36.8)); TMP (HR 0.63 (95% CI 0.50 to 0.78), median PFS:25.7 months (20.8 to 32.4)); VMP (HR 0.56 (95% CI 0.35 to 0.90), median PFS: 28.9 months (18.0 to 46.3)); and VRDc (HR 0.34 (95% CI 0.20 to 0.58), median PFS: 47.6 months (27.9 to 81.0)) may result in a large increase in PFS (low certainty) compared to MP (median reported PFS: 16.2 months). Adverse events The risk of polyneuropathies may be lower with RD compared to treatment with MP (RR 0.57 (95% CI 0.16 to 1.99), risk for RD: 0.5% (0.1 to 1.8), mean reported risk for MP: 0.9% (10 of 1074 patients affected), low certainty). However, the CIs are also compatible with no difference or an increase in neuropathies. Treatment with TMP (RR 4.44 (95% CI1.77 to 11.11), risk: 4.0% (1.6 to 10.0)) and VMP (RR 88.22 (95% CI 5.36 to 1451.11), risk: 79.4% (4.8 to 1306.0)) probably results in a large increase in polyneuropathies compared to MP (moderate certainty). No study reported the amount of participants with grade ≥ 3 polyneuropathies for treatment with VRDc. VMP probably increases the proportion of participants with serious adverse events (SAEs) compared to MP (RR 1.28 (95% CI 1.06 to 1.54), risk for VMP: 46.2% (38.3 to 55.6), mean risk for MP: 36.1% (177 of 490 patients affected), moderate certainty). RD, TMP, and VRDc were not connected to MP in the network and the risk of SAEs could not be compared. Treatment with RD (RR 4.18 (95% CI 2.13 to 8.20), NMA-risk: 38.5% (19.6 to 75.4)); and TMP (RR 4.10 (95% CI 2.40 to 7.01), risk: 37.7% (22.1 to 64.5)) results in a large increase of withdrawals from the trial due to adverse events (high certainty) compared to MP (mean reported risk: 9.2% (77 of 837 patients withdrew)). The risk is probably slightly increased with VMP (RR 1.06 (95% CI 0.63 to 1.81), risk: 9.75% (5.8 to 16.7), moderate certainty), while it is much increased with VRDc (RR 8.92 (95% CI 3.82 to 20.84), risk: 82.1% (35.1 to 191.7), high certainty) compared to MP. Quality of life QoL was reported in four studies for seven different treatment regimens (MP, MPc, RD, RMP, RMPc, TMP, TMPc) and was measured with four different tools. Assessment and reporting differed between studies and could not be meta-analysed. However, all studies reported an improvement of QoL after initiation of anti-myeloma treatment for all assessed treatment regimens.

AUTHORS' CONCLUSIONS

Based on our four pre-selected comparisons of interest, continuous treatment with VRD had the largest survival benefit compared with MP, while RD and TMP also probably considerably increase survival. However, treatment combinations of V, R, and T also substantially increase the incidence of AEs, and lead to a higher risk of treatment discontinuation. Their effectiveness and safety profiles may best be analysed in further randomised head-to-head trials. Further trials should focus on consistent reporting of safety outcomes and should use a standardised instrument to evaluate QoL to ensure comparability of treatment-combinations.

Platelet transfusion: Alloimmunization and refractoriness

The transfusion of platelets for both prophylaxis and treatment of bleeding is relevant to all areas of medicine and surgery. Historically, guidance regarding platelet transfusion has been limited by a lack of good quality clinical trials and so has been based largely on expert opinion. In recent years however there has been renewed interest in methods to prevent and treat hemorrhage, and the field has benefited from a number of large clinical trials. Some studies, such as platelet transfusion versus standard care after acute stroke due to spontaneous cerebral haemorrhage associated with antiplatelet therapy (PATCH) and platelets for neonatal transfusion Study 2 (PLANET-2), have reported an increased risk of harm with platelet transfusion in specific patient groups. These studies suggest a wider role of platelets beyond hemostasis, and highlight the need for further clinical trials to better understand the risks and benefits of platelet transfusions. This review evaluates the indications for platelet transfusion, both prophylactic and therapeutic, in the light of recent studies and clinical trials. It highlights new developments in the fields of platelet storage and platelet substitutes, and novel ways to avoid complications associated with platelet transfusions. Lastly, it reviews initiatives designed to reduce inappropriate use of platelet transfusions and to preserve this valuable resource for situations where there is evidence for their beneficial effect.

Regular long-term red blood cell transfusions for managing chronic chest complications in sickle cell disease

BACKGROUND

Sickle cell disease is a genetic haemoglobin disorder, which can cause severe pain, significant end-organ damage, pulmonary complications, and premature death. Sickle cell disease is one of the most common severe monogenic disorders in the world, due to the inheritance of two abnormal haemoglobin (beta globin) genes. The two most common chronic chest complications due to sickle cell disease are pulmonary hypertension and chronic sickle lung disease. These complications can lead to morbidity (such as reduced exercise tolerance) and increased mortality. This is an update of a Cochrane Review first published in 2011 and updated in 2014 and 2016.

OBJECTIVES

We wanted to determine whether trials involving people with sickle cell disease that compare regular long-term blood transfusion regimens with standard care, hydroxycarbamide (hydroxyurea) any other drug treatment show differences in the following: mortality associated with chronic chest complications; severity of established chronic chest complications; development and progression of chronic chest complications; serious adverse events.

SEARCH METHODS

We searched the Cochrane Cystic Fibrosis and Genetic Disorders Group's Haemoglobinopathies Trials Register. Date of the last search: 19 September 2019. We also searched for randomised controlled trials in the Cochrane Central Register of Controlled Trials (CENTRAL) (the Cochrane Library, Issue 10, 14 November 2018), MEDLINE (from 1946), Embase (from 1974), CINAHL (from 1937), the Transfusion Evidence Library (from 1950), and ongoing trial databases to 14 November 2018.

SELECTION CRITERIA

We included randomised controlled trials of people of any age with one of four common sickle cell disease genotypes, i.e. Hb SS, Sβº, SC, or Sβ⁺ that compared regular red blood cell transfusion regimens (either simple or exchange transfusions) to hydroxycarbamide, any other drug treatment, or to standard care that were aimed at reducing the development or progression of chronic chest complications (chronic sickle lung and pulmonary hypertension).

DATA COLLECTION AND ANALYSIS

We used the standard methodological procedures expected by Cochrane.

MAIN RESULTS

No studies matching the selection criteria were found.

AUTHORS' CONCLUSIONS

There is a need for randomised controlled trials looking at the role of long-term transfusion therapy in pulmonary hypertension and chronic sickle lung disease. Due to the chronic nature of the conditions, such trials should aim to use a combination of objective and subjective measures to assess participants repeatedly before and after the intervention.

The TREATT Trial (TRial to EvaluAte Tranexamic acid therapy in Thrombocytopenia): safety and efficacy of tranexamic acid in patients with haematological malignancies with severe thrombocytopenia: study protocol for a double-blind randomised controlled trial

Background

Patients with haematological malignancies often develop thrombocytopenia as a consequence of either their disease or its treatment. Platelet transfusions are commonly given to raise a low platelet count and reduce the risk of clinical bleeding (prophylaxis) or stop active bleeding (therapy). Recent studies have shown that many patients continue to experience bleeding despite the use of prophylactic platelet transfusions. Tranexamic acid is an anti-fibrinolytic, which reduces the breakdown of clots formed in response to bleeding. Anti-fibrinolytics have been shown to prevent bleeding, decrease blood loss and use of red cell transfusions in elective and emergency surgery, and are used widely in these settings. The aim of this trial is to test whether giving tranexamic acid to patients receiving treatment for haematological malignancies reduces the risk of bleeding or death and the need for platelet transfusions.

Methods

This is a multinational randomised, double-blind, placebo-controlled, parallel, superiority trial. Patients will be randomly assigned to receive tranexamic acid (given intravenously or orally) or a matching placebo in a 1:1 ratio, stratified by site. Patients with haematological malignancies receiving intensive chemotherapy or stem cell transplantation (or both) who are at least 18 years of age and expected to become severely thrombocytopenic for at least 5 days will be eligible for this trial. The primary outcome of the trial is the proportion of patients who died or had bleeding of World Health Organization grade 2 or above during the first 30 days of the trial. We will measure the rates of bleeding daily by using a short, structured assessment of bleeding, and we will record the number of transfusions given to patients. We will assess the risk of arterial and venous thrombosis for 120 days from the start of trial treatment.

Discussion

This trial will assess the safety and efficacy of using prophylactic tranexamic acid during a period of intensive chemotherapy and associated thrombocytopenia in people with haematological disorders.

Trial registration

This study was prospectively registered on Current Controlled Trials on 25 March 2015 (ISRCTN73545489) and is also registered on ClinicalTrials.gov (NCT03136445).

Electronic supplementary material

The online version of this article (10.1186/s13063-019-3663-2) contains supplementary material, which is available to authorized users.

Interim PET-results for prognosis in adults with Hodgkin lymphoma: a systematic review and meta-analysis of prognostic factor studies

BACKGROUND

Hodgkin lymphoma (HL) is one of the most common haematological malignancies in young adults and, with cure rates of 90%, has become curable for the majority of individuals. Positron emission tomography (PET) is an imaging tool used to monitor a tumour's metabolic activity, stage and progression. Interim PET during chemotherapy has been posited as a prognostic factor in individuals with HL to distinguish between those with a poor prognosis and those with a better prognosis. This distinction is important to inform decision-making on the clinical pathway of individuals with HL.

OBJECTIVES

To determine whether in previously untreated adults with HL receiving first-line therapy, interim PET scan results can distinguish between those with a poor prognosis and those with a better prognosis, and thereby predict survival outcomes in each group.

SEARCH METHODS

We searched MEDLINE, Embase, CENTRAL and conference proceedings up until April 2019. We also searched one trial registry (ClinicalTrials.gov).

SELECTION CRITERIA

We included retrospective and prospective studies evaluating interim PET scans in a minimum of 10 individuals with HL (all stages) undergoing first-line therapy. Interim PET was defined as conducted during therapy (after one, two, three or four treatment cycles). The minimum follow-up period was at least 12 months. We excluded studies if the trial design allowed treatment modification based on the interim PET scan results.

DATA COLLECTION AND ANALYSIS

We developed a data extraction form according to the Checklist for Critical Appraisal and Data Extraction for Systematic Reviews of Prediction Modelling Studies (CHARMS). Two teams of two review authors independently screened the studies, extracted data on overall survival (OS), progression-free survival (PFS) and PET-associated adverse events (AEs), assessed risk of bias (per outcome) according to the Quality in Prognosis Studies (QUIPS) tool, and assessed the certainty of the evidence (GRADE). We contacted investigators to obtain missing information and data.

MAIN RESULTS

Our literature search yielded 11,277 results. In total, we included 23 studies (99 references) with 7335 newly-diagnosed individuals with classic HL (all stages).Participants in 16 studies underwent (interim) PET combined with computed tomography (PET-CT), compared to PET only in the remaining seven studies. The standard chemotherapy regimen included ABVD (16) studies, compared to BEACOPP or other regimens (seven studies). Most studies (N = 21) conducted interim PET scans after two cycles (PET2) of chemotherapy, although PET1, PET3 and PET4 were also reported in some studies. In the meta-analyses, we used PET2 data if available as we wanted to ensure homogeneity between studies. In most studies interim PET scan results were evaluated according to the Deauville 5-point scale (N = 12).Eight studies were not included in meta-analyses due to missing information and/or data; results were reported narratively. For the remaining studies, we pooled the unadjusted hazard ratio (HR). The timing of the outcome measurement was after two or three years (the median follow-up time ranged from 22 to 65 months) in the pooled studies.Eight studies explored the independent prognostic ability of interim PET by adjusting for other established prognostic factors (e.g. disease stage, B symptoms). We did not pool the results because the multivariable analyses adjusted for a different set of factors in each study.Overall survivalTwelve (out of 23) studies reported OS. Six of these were assessed as low risk of bias in all of the first four domains of QUIPS (study participation, study attrition, prognostic factor measurement and outcome measurement). The other six studies were assessed as unclear, moderate or high risk of bias in at least one of these four domains. Nine studies were assessed as high risk, and three studies as moderate risk of bias for the domain study confounding. Eight studies were assessed as low risk, and four studies as high risk of bias for the domain statistical analysis and reporting.We pooled nine studies with 1802 participants. Participants with HL who have a negative interim PET scan result probably have a large advantage in OS compared to those with a positive interim PET scan result (unadjusted HR 5.09, 95% confidence interval (CI) 2.64 to 9.81, I² = 44%, moderate-certainty evidence). In absolute values, this means that 900 out of 1000 participants with a negative interim PET scan result will probably survive longer than three years compared to 585 (95% CI 356 to 757) out of 1000 participants with a positive result.Adjusted results from two studies also indicate an independent prognostic value of interim PET scan results (moderate-certainty evidence).Progression-free survival Twenty-one studies reported PFS. Eleven out of 21 were assessed as low risk of bias in the first four domains. The remaining were assessed as unclear, moderate or high risk of bias in at least one of the four domains. Eleven studies were assessed as high risk, nine studies as moderate risk and one study as low risk of bias for study confounding. Eight studies were assessed as high risk, three as moderate risk and nine as low risk of bias for statistical analysis and reporting.We pooled 14 studies with 2079 participants. Participants who have a negative interim PET scan result may have an advantage in PFS compared to those with a positive interim PET scan result, but the evidence is very uncertain (unadjusted HR 4.90, 95% CI 3.47 to 6.90, I² = 45%, very low-certainty evidence). This means that 850 out of 1000 participants with a negative interim PET scan result may be progression-free longer than three years compared to 451 (95% CI 326 to 569) out of 1000 participants with a positive result.Adjusted results (not pooled) from eight studies also indicate that there may be an independent prognostic value of interim PET scan results (low-certainty evidence).PET-associated adverse eventsNo study measured PET-associated AEs.

AUTHORS' CONCLUSIONS

This review provides moderate-certainty evidence that interim PET scan results predict OS, and very low-certainty evidence that interim PET scan results predict progression-free survival in treated individuals with HL. This evidence is primarily based on unadjusted data. More studies are needed to test the adjusted prognostic ability of interim PET against established prognostic factors.

Six-month outcomes after restrictive or liberal transfusion for cardiac surgery (TRICS III trial)

CLINICAL QUESTION

Is transfusing red cell components using a restrictive transfusion threshold (Hb < 75 g L^-1 ) as safe as a liberal transfusion threshold (Hb < 95 g L^-1 in intensive care and < 85 g L^-1 outside intensive care) during and after cardiac surgery for adults at moderate to high risk of death?

EVIDENCE FROM TRIAL

In adults undergoing cardiac surgery who were at moderate to high risk for death, using a restrictive red-cell transfusion threshold was as safe as a liberal red cell transfusion threshold (composite outcome of death from any cause, myocardial infarction, stroke or new-onset renal failure with dialysis at 6 months after surgery).

Prophylactic platelet transfusions prior to surgery for people with a low platelet count

BACKGROUND

People with thrombocytopenia often require a surgical procedure. A low platelet count is a relative contraindication to surgery due to the risk of bleeding. Platelet transfusions are used in clinical practice to prevent and treat bleeding in people with thrombocytopenia. Current practice in many countries is to correct thrombocytopenia with platelet transfusions prior to surgery. Alternatives to platelet transfusion are also used prior surgery.

OBJECTIVES

To determine the clinical effectiveness and safety of prophylactic platelet transfusions prior to surgery for people with a low platelet count.

SEARCH METHODS

We searched the following major data bases: Cochrane Central Register of Controlled Trials (CENTRAL; 2017, Issue 2), PubMed (e-publications only), Ovid MEDLINE, Ovid Embase, the Transfusion Evidence Library and ongoing trial databases to 11 December 2017.

SELECTION CRITERIA

We included all randomised controlled trials (RCTs), as well as non-RCTs and controlled before-and-after studies (CBAs), that met Cochrane EPOC (Effective Practice and Organisation of Care) criteria, that involved the transfusion of platelets prior to surgery (any dose, at any time, single or multiple) in people with low platelet counts. We excluded studies on people with a low platelet count who were actively bleeding.

DATA COLLECTION AND ANALYSIS

We used standard methodological procedures expected by Cochrane for data collection. We were only able to combine data for two outcomes and we presented the rest of the findings in a narrative form.

MAIN RESULTS

We identified five RCTs, all conducted in adults; there were no eligible non-randomised studies. Three completed trials enrolled 180 adults and two ongoing trials aim to include 627 participants. The completed trials were conducted between 2005 and 2009. The two ongoing trials are scheduled to complete recruitment by October 2019. One trial compared prophylactic platelet transfusions to no transfusion in people with thrombocytopenia in an intensive care unit (ICU). Two small trials, 108 participants, compared prophylactic platelet transfusions to other alternative treatments in people with liver disease. One trial compared desmopressin to fresh frozen plasma or one unit of platelet transfusion or both prior to surgery. The second trial compared platelet transfusion prior to surgery with two types of thrombopoietin mimetics: romiplostim and eltrombopag. None of the included trials were free from methodological bias. No included trials compared different platelet count thresholds for administering a prophylactic platelet transfusion prior to surgery. None of the included trials reported on all the review outcomes and the overall quality per reported outcome was very low.None of the three completed trials reported: all-cause mortality at 90 days post surgery; mortality secondary to bleeding, thromboembolism or infection; number of red cell or platelet transfusions per participant; length of hospital stay; or quality of life.None of the trials included children or people who needed major surgery or emergency surgical procedures.Platelet transfusion versus no platelet transfusion (1 trial, 72 participants)We were very uncertain whether giving a platelet transfusion prior to surgery had any effect on all-cause mortality within 30 days (1 trial, 72 participants; risk ratio (RR) 0.78, 95% confidence interval (CI) 0.41 to 1.45; very-low quality evidence). We were very uncertain whether giving a platelet transfusion prior to surgery had any effect on the risk of major (1 trial, 64 participants; RR 1.60, 95% CI 0.29 to 8.92; very low-quality evidence), or minor bleeding (1 trial, 64 participants; RR 1.29, 95% CI 0.90 to 1.85; very-low quality evidence). No serious adverse events occurred in either study arm (1 trial, 72 participants, very low-quality evidence).Platelet transfusion versus alternative to platelet transfusion (2 trials, 108 participants)We were very uncertain whether giving a platelet transfusion prior to surgery compared to an alternative has any effect on the risk of major (2 trials, 108 participants; no events; very low-quality evidence), or minor bleeding (desmopressin: 1 trial, 36 participants; RR 0.89, 95% CI 0.06 to 13.23; very-low quality evidence: thrombopoietin mimetics: 1 trial, 65 participants; no events; very-low quality evidence). We were very uncertain whether there was a difference in transfusion-related adverse effects between the platelet transfused group and the alternative treatment group (desmopressin: 1 trial, 36 participants; RR 2.70, 95% CI 0.12 to 62.17; very-low quality evidence).

AUTHORS' CONCLUSIONS

Findings of this review were based on three small trials involving minor surgery in adults with thrombocytopenia. We found insufficient evidence to recommend the administration of preprocedure prophylactic platelet transfusions in this situation with a lack of evidence that transfusion resulted in a reduction in postoperative bleeding or all-cause mortality. The small number of trials meeting the inclusion criteria and the limitation in reported outcomes across the trials precluded meta-analysis for most outcomes. Further adequately powered trials, in people of all ages, of prophylactic platelet transfusions compared with no transfusion, other alternative treatments, and considering different platelet thresholds prior to planned and emergency surgical procedures are required. Future trials should include major surgery and report on bleeding, adverse effects, mortality (as a long-term outcome) after surgery, duration of hospital stay and quality of life measures.

Red blood cell transfusion to treat or prevent complications in sickle cell disease: an overview of Cochrane reviews

BACKGROUND

Globally, sickle cell disease (SCD) is one of the commonest severe monogenic disorders, due to the inheritance of two abnormal haemoglobin (beta globin) genes. SCD can cause severe pain, significant end-organ damage, pulmonary complications, and premature death. Red blood cell (RBC) transfusions are used to treat complications of SCD, e.g. acute chest syndrome (ACS) (this often involves a single transfusion episode), or they can be part of a regular long-term transfusion programme to prevent SCD complications.

OBJECTIVES

To summarize the evidence in Cochrane Reviews of the effectiveness and safety of RBC transfusions versus no transfusion, or restrictive (to increase the total haemoglobin) versus liberal (to decrease the haemoglobin S level below a specified percentage) transfusion, for treating or preventing complications experienced by people with SCD.

METHODS

We included Cochrane Reviews of randomised or quasi-randomised controlled trials published in the Cochrane Database of Systematic Reviews, that addressed various SCD complications and had RBC transfusion as an intervention or comparator. We assessed the methodological quality of included reviews according to the AMSTAR quality assessment.

MAIN RESULTS

We included 15 Cochrane Reviews, 10 of which had no included studies with an RBC transfusion intervention (five reported RCTs with other interventions; and five contained no studies). Five of the 15 reviews included participants randomised to RBC transfusion, but in one of these reviews only 10 participants were randomised with no usable data. Four reviews (nine trials with 1502 participants) reported data comparing short- or long-term RBC transfusions versus standard care, disease-modifying agents, a restrictive versus a liberal transfusion strategy and long-term RBC transfusions versus transfusions to treat complications. All reviews were of high quality according to AMSTAR quality assessment, however, the quality of the included trials was highly variable across outcomes. Trials were downgraded according to GRADE methodology for risk of bias, indirectness (most trials were conducted in children with HbSS), and imprecision (outcomes had wide confidence intervals).In all four reviews and all comparisons there was little or no difference in the risk of death (very low-quality evidence). There were either no deaths or death was a rare event.Short-term RBC transfusion versus standard care (one review: two trials, 434 participants, GRADE very low- to low-quality evidence)In people undergoing low- to medium-risk surgery, RBC transfusions may decrease the risk of acute chest syndrome (ACS) in people with African haplotypes compared to standard care (low-quality evidence), but there was little or no difference in people with the Arabic haplotype (very-low quality evidence). There was also little or no difference in the risk of other SCD-related or transfusion-related complications (very-low quality evidence).Long-term RBC transfusion versus standard care (two reviews: three trials, 405 participants, very low- to moderate-quality evidence)In children and adolescents at high risk of stroke (abnormal transcranial doppler (TCD) velocities or silent cerebral infarct (SCI)), long-term RBC transfusions probably decrease the risk of stroke (moderate-quality evidence) and may decrease the risk of ACS and painful crisis compared to standard care (low-quality evidence). Long-term RBC transfusions may also decrease the risk of SCI in children with abnormal TCD velocities (low-quality evidence), but there may be little or no difference in the risk of SCI in children with normal TCD velocities and previous SCI (low-quality evidence).In children and adolescents already receiving long-term RBC transfusions for preventing stroke, in comparison to standard care, continuing long-term RBC transfusions may reduce the risk of SCI (low-quality evidence) but we do not know whether there is a difference in the risk of stroke (very-low quality evidence). In children with normal TCD velocities and SCI there was little or no difference in the risk of alloimmunisation or transfusion reactions, but RBC transfusions may increase the risk of iron overload (low-quality evidence).Long-term RBC transfusion versus RBC transfusion to treat complications (one review: one trial, 72 participants, very low- to low-quality evidence)In pregnant women, long-term RBC transfusions may decrease the risk of painful crisis compared to transfusion for complications (low-quality evidence); but there may be little or no difference in the risk of other SCD-related complications or transfusion reactions (very-low quality evidence).RBC transfusion versus disease-modifying agents (hydroxyurea) (two reviews: two trials; 254 participants, very low- to low-quality evidence)For primary prevention of stroke in children, with abnormal TCD and no severe vasculopathy on magnetic resonance imaging/magnetic resonance angiography (MRI/MRA), who have received at least one year of RBC transfusions, we do not know whether there is a difference between RBC transfusion and disease-modifying agents in the risk of stroke; SCI; ACS; or painful crisis (very-low quality evidence). There may be little or no difference in the risk of iron overload (low-quality evidence).Similarly, for secondary prevention of stroke in children and adolescents, we do not know whether there is a difference between these interventions in the risk of stroke; SCI; or ACS (very-low quality evidence); but hydroxyurea with phlebotomy may increase the risk of painful crisis and global SCD serious adverse events compared to RBC transfusion (low-quality evidence). There may be little or no difference in the risk of iron overload (low-quality evidence).Restrictive versus liberal RBC transfusion strategy (one review: one trial; 230 participants, very low-quality evidence)In people undergoing cholecystectomy, there was little or no difference between strategies in the risk of SCD-related or transfusion-related complications (very-low quality evidence).

AUTHORS' CONCLUSIONS

This overview provides support from two high-quality Cochrane Reviews for the use of RBC transfusions in preventing stroke in children and adolescents at high risk of stroke (abnormal TCDs or SCI) and evidence that it may decrease the risk of SCI in children with abnormal TCD velocities. In addition RBC transfusions may reduce the risk of ACS and painful crisis in this population.This overview highlights the lack of high-quality evidence in adults with SCD and the number of reviews that have no evidence for the use of RBC transfusions across a spectrum of SCD complications. Also of concern is the variable and often incomplete reporting of patient-relevant outcomes in the included trials such as SCD-related serious adverse events and quality of life.

Comparison of a therapeutic-only versus prophylactic platelet transfusion policy for people with congenital or acquired bone marrow failure disorders

BACKGROUND

Bone marrow disorders encompass a group of diseases characterised by reduced production of red cells, white cells, and platelets, or defects in their function, or both. The most common bone marrow disorder is myelodysplastic syndrome. Thrombocytopenia, a low platelet count, commonly occurs in people with bone marrow failure. Platetet transfusions are routinely used in people with thrombocytopenia secondary to bone marrow failure disorders to treat or prevent bleeding. Myelodysplastic syndrome is currently the most common reason for receiving a platelet transfusion in some Western countries.

OBJECTIVES

To determine whether a therapeutic-only platelet transfusion policy (transfusion given when patient is bleeding) is as effective and safe as a prophylactic platelet transfusion policy (transfusion given to prevent bleeding according to a prespecified platelet threshold) in people with congenital or acquired bone marrow failure disorders.

SEARCH METHODS

We searched for randomised controlled trials (RCTs), non-RCTs, and controlled before-after studies (CBAs) in the Cochrane Central Register of Controlled Trials (CENTRAL) (the Cochrane Library 2017, Issue 9), Ovid MEDLINE (from 1946), Ovid Embase (from 1974), PubMed (e-publications only), the Transfusion Evidence Library (from 1950), and ongoing trial databases to 12 October 2017.

SELECTION CRITERIA

We included RCTs, non-RCTs, and CBAs that involved the transfusion of platelet concentrates (prepared either from individual units of whole blood or by apheresis any dose, frequency, or transfusion trigger) and given to treat or prevent bleeding among people with congenital or acquired bone marrow failure disorders.We excluded uncontrolled studies, cross-sectional studies, and case-control studies. We excluded cluster-RCTs, non-randomised cluster trials, and CBAs with fewer than two intervention sites and two control sites due to the risk of confounding. We included all people with long-term bone marrow failure disorders that require platelet transfusions, including neonates. We excluded studies of alternatives to platelet transfusion, or studies of people receiving intensive chemotherapy or a stem cell transplant.

DATA COLLECTION AND ANALYSIS

We used the standard methodological procedures outlined by Cochrane. Due to the absence of evidence we were unable to report on any of the review outcomes.

MAIN RESULTS

We identified one RCT that met the inclusion criteria for this review. The study enrolled only nine adults with MDS over a three-year study duration period. The trial was terminated due to poor recruitment rate (planned recruitment 60 participants over two years). Assessment of the risk of bias was not possible for all domains. The trial was a single-centre, single-blind trial. The clinical and demographic characteristics of the participants were never disclosed. The trial outcomes relevant to this review were bleeding assessments, mortality, quality of life, and length of hospital stay, but no data were available to report on any of these outcomes.We identified no completed non-RCTs or CBAs.We identified no ongoing RCTs, non-RCTs, or CBAs.

AUTHORS' CONCLUSIONS

We found no evidence to determine the safety and efficacy of therapeutic platelet transfusion compared with prophylactic platelet transfusion for people with long-term bone marrow failure disorders. This review underscores the urgency of prioritising research in this area. People with bone marrow failure depend on long-term platelet transfusion support, but the only trial that assessed a therapeutic strategy was halted. There is a need for good-quality studies comparing a therapeutic platelet transfusion strategy with a prophylactic platelet transfusion strategy; such trials should include outcomes that are important to patients, such as quality of life, length of hospital admission, and risk of bleeding.

Interventions for improving adherence to iron chelation therapy in people with sickle cell disease or thalassaemia

BACKGROUND

Regularly transfused people with sickle cell disease (SCD) and people with thalassaemia (who are transfusion-dependent or non-transfusion-dependent) are at risk of iron overload. Iron overload can lead to iron toxicity in vulnerable organs such as the heart, liver and endocrine glands; which can be prevented and treated with iron chelating agents. The intensive demands and uncomfortable side effects of therapy can have a negative impact on daily activities and well-being, which may affect adherence.

OBJECTIVES

To identify and assess the effectiveness of interventions (psychological and psychosocial, educational, medication interventions, or multi-component interventions) to improve adherence to iron chelation therapy in people with SCD or thalassaemia.

SEARCH METHODS

We searched CENTRAL (the Cochrane Library), MEDLINE, Embase, CINAHL, PsycINFO, Psychology and Behavioral Sciences Collection, Web of Science Science & Social Sciences Conference Proceedings Indexes and ongoing trial databases (01 February 2017). We searched the Cochrane Cystic Fibrosis and Genetic Disorders Group's Haemoglobinopathies Trials Register (12 December 2017).

SELECTION CRITERIA

For trials comparing medications or medication changes, only randomised controlled trials (RCTs) were eligible for inclusion.For studies including psychological and psychosocial interventions, educational Interventions, or multi-component interventions, non-RCTs, controlled before-after studies, and interrupted time series studies with adherence as a primary outcome were also eligible for inclusion.

DATA COLLECTION AND ANALYSIS

Three authors independently assessed trial eligibility, risk of bias and extracted data. The quality of the evidence was assessed using GRADE.

MAIN RESULTS

We included 16 RCTs (1525 participants) published between 1997 and 2017. Most participants had β-thalassaemia major; 195 had SCD and 88 had β-thalassaemia intermedia. Mean age ranged from 11 to 41 years. One trial was of medication management and 15 RCTs were of medication interventions. Medications assessed were subcutaneous deferoxamine, and two oral-chelating agents, deferiprone and deferasirox.We rated the quality of evidence as low to very low across all outcomes identified in this review.Three trials measured quality of life (QoL) with validated instruments, but provided no analysable data and reported no difference in QoL.Deferiprone versus deferoxamineWe are uncertain whether deferiprone increases adherence to iron chelation therapy (four trials, very low-quality evidence). Results could not be combined due to considerable heterogeneity (participants' age and different medication regimens). Medication adherence was high (deferiprone (85% to 94.9%); deferoxamine (71.6% to 93%)).We are uncertain whether deferiprone increases the risk of agranulocytosis, risk ratio (RR) 7.88 (99% confidence interval (CI) 0.18 to 352.39); or has any effect on all-cause mortality, RR 0.44 (95% CI 0.12 to 1.63) (one trial; 88 participants; very low-quality evidence).Deferasirox versus deferoxamineWe are uncertain whether deferasirox increases adherence to iron chelation therapy, mean difference (MD) -1.40 (95% CI -3.66 to 0.86) (one trial; 197 participants; very-low quality evidence). Medication adherence was high (deferasirox (99%); deferoxamine (100%)). We are uncertain whether deferasirox decreases the risk of thalassaemia-related serious adverse events (SAEs), RR 0.95 (95% CI 0.41 to 2.17); or all-cause mortality, RR 0.96 (95% CI 0.06 to 15.06) (two trials; 240 participants; very low-quality evidence).We are uncertain whether deferasirox decreases the risk of SCD-related pain crises, RR 1.05 (95% CI 0.68 to 1.62); or other SCD-related SAEs, RR 1.08 (95% CI 0.77 to 1.51) (one trial; 195 participants; very low-quality evidence).Deferasirox film-coated tablet (FCT) versus deferasirox dispersible tablet (DT)Deferasirox FCT may make little or no difference to adherence, RR 1.10 (95% CI 0.99 to 1.22) (one trial; 173 participants; low-quality evidence). Medication adherence was high (FCT (92.9%); DT (85.3%)).We are uncertain if deferasirox FCT increases the incidence of SAEs, RR 1.22 (95% CI 0.62 to 2.37); or all-cause mortality, RR 2.97 (95% CI 0.12 to 71.81) (one trial; 173 participants; very low-quality evidence).Deferiprone and deferoxamine combined versus deferiprone alone We are uncertain if deferiprone and deferoxamine combined increases adherence to iron chelation therapy (very low-quality evidence). Medication adherence was high (deferiprone 92.7% (range 37% to 100%) to 93.6% (range 56% to 100%); deferoxamine 70.6% (range 25% to 100%).Combination therapy may make little or no difference to the risk of SAEs, RR 0.15 (95% CI 0.01 to 2.81) (one trial; 213 participants; low-quality evidence).We are uncertain if combination therapy decreases all-cause mortality, RR 0.77 (95% CI 0.18 to 3.35) (two trials; 237 participants; very low-quality evidence).Deferiprone and deferoxamine combined versus deferoxamine aloneDeferiprone and deferoxamine combined may have little or no effect on adherence to iron chelation therapy (four trials; 216 participants; low-quality evidence). Medication adherence was high (deferoxamine 91.4% to 96.1%; deferiprone: 82.4%)Deferiprone and deferoxamine combined, may have little or no difference in SAEs or mortality (low-quality evidence). No SAEs occurred in three trials and were not reported in one trial. No deaths occurred in two trials and were not reported in two trials.Deferiprone and deferoxamine combined versus deferiprone and deferasirox combinedDeferiprone and deferasirox combined may improve adherence to iron chelation therapy, RR 0.84 (95% CI 0.72 to 0.99) (one trial; 96 participants; low-quality evidence). Medication adherence was high (deferiprone and deferoxamine: 80%; deferiprone and deferasirox: 95%).We are uncertain if deferiprone and deferasirox decreases the incidence of SAEs, RR 1.00 (95% CI 0.06 to 15.53) (one trial; 96 participants; very low-quality evidence).There were no deaths in the trial (low-quality evidence).Medication management versus standard careWe are uncertain if medication management improves health-related QoL (one trial; 48 participants; very low-quality evidence). Adherence was only measured in one arm of the trial.

AUTHORS' CONCLUSIONS

The medication comparisons included in this review had higher than average adherence rates not accounted for by differences in medication administration or side effects.Participants may have been selected based on higher adherence to trial medications at baseline. Also, within the clinical trial context, there is increased attention and involvement of clinicians, thus high adherence rates may be an artefact of trial participation.Real-world, pragmatic trials in community and clinic settings are needed that examine both confirmed or unconfirmed adherence strategies that may increase adherence to iron chelation therapy.Due to lack of evidence this review cannot comment on intervention strategies for different age groups.

Use of platelet transfusions prior to lumbar punctures or epidural anaesthesia for the prevention of complications in people with thrombocytopenia

BACKGROUND

People with a low platelet count (thrombocytopenia) often require lumbar punctures or an epidural anaesthetic. Lumbar punctures can be diagnostic (haematological malignancies, subarachnoid haematoma, meningitis) or therapeutic (spinal anaesthetic, administration of chemotherapy). Epidural catheters are placed for administration of epidural anaesthetic. Current practice in many countries is to correct thrombocytopenia with platelet transfusions prior to lumbar punctures and epidural anaesthesia, in order to mitigate the risk of serious procedure-related bleeding. However, the platelet count threshold recommended prior to these procedures varies significantly from country to country. This indicates significant uncertainty among clinicians regarding the correct management of these patients. The risk of bleeding appears to be low, but if bleeding occurs it can be very serious (spinal haematoma). Consequently, people may be exposed to the risks of a platelet transfusion without any obvious clinical benefit.This is an update of a Cochrane Review first published in 2016.

OBJECTIVES

To assess the effects of different platelet transfusion thresholds prior to a lumbar puncture or epidural anaesthesia in people with thrombocytopenia (low platelet count).

SEARCH METHODS

We searched for randomised controlled trials (RCTs), non-randomised controlled trials (nRCTs), controlled before-after studies (CBAs), interrupted time series studies (ITSs), and cohort studies in CENTRAL (the Cochrane Library 2018, Issue 1), MEDLINE (from 1946), Embase (from 1974), the Transfusion Evidence Library (from 1950), and ongoing trial databases to 13 February 2018.

SELECTION CRITERIA

We included RCTs, nRCTs, CBAs, ITSs, and cohort studies involving transfusions of platelet concentrates, prepared either from individual units of whole blood or by apheresis, and given to prevent bleeding in people of any age with thrombocytopenia requiring insertion of a lumbar puncture needle or epidural catheter.The original review only included RCTs.

DATA COLLECTION AND ANALYSIS

We used standard methodological procedures expected by Cochrane for including RCTs, nRCTs, CBAs, and ITSs. Two review authors independently assessed studies for eligibility and risk of bias and extracted data. Results were only expressed narratively.

MAIN RESULTS

We identified no completed or ongoing RCTs, nRCTs, CBAs, or ITSs. No studies included people undergoing an epidural procedure. No studies compared different platelet count thresholds prior to a procedure.In this update we identified three retrospective cohort studies that contained participants who did and did not receive platelet transfusions prior to lumbar puncture procedures. All three studies were carried out in people with cancer, most of whom had a haematological malignancy. Two studies were in children, and one was in adults.The number of participants receiving platelet transfusions prior to the lumbar puncture procedures was not reported in one study. We therefore only summarised in a narrative form the relevant outcomes from two studies (150 participants; 129 children and 21 adults), in which the number of participants who received the transfusion was given.We judged the overall risk of bias for all reported outcomes for both studies as 'serious' based on the ROBINS-I tool.No procedure-related major bleeding occurred in the two studies that reported this outcome (2 studies, 150 participants, no cases, very low-quality evidence).There was no evidence of a difference in the risk of minor bleeding (traumatic tap) in participants who received platelet transfusions before a lumbar puncture and those who did not receive a platelet transfusion before the procedure (2 studies, 150 participants, very low-quality evidence). One of the 14 adults who received a platelet transfusion experienced minor bleeding (traumatic tap; defined as at least 500 x 10⁶/L red blood cells in the cerebrospinal fluid); none of the seven adults who did not receive a platelet transfusion experienced this event. Ten children experienced minor bleeding (traumatic taps; defined as at least 100 x 10⁶/L red blood cells in the cerebrospinal fluid), six out of the 57 children who received a platelet transfusion and four out of the 72 children who did not receive a platelet transfusion.No serious adverse events occurred in the one study that reported this outcome (1 study, 21 participants, very low-quality evidence).We found no studies that evaluated all-cause mortality within 30 days from the lumbar puncture procedure, length of hospital stay, proportion of participants who received platelet transfusions, or quality of life.

AUTHORS' CONCLUSIONS

We found no evidence from RCTs or non-randomised studies on which to base an assessment of the correct platelet transfusion threshold prior to insertion of a lumbar puncture needle or epidural catheter. There are no ongoing registered RCTs assessing the effects of different platelet transfusion thresholds prior to the insertion of a lumbar puncture or epidural anaesthesia in people with thrombocytopenia. Any future study would need to be very large to detect a difference in the risk of bleeding. A study would need to be designed with at least 47,030 participants to be able to detect an increase in the number of people who had major procedure-related bleeding from 1 in 1000 to 2 in 1000. The use of a central data collection register or routinely collected electronic records (big data) is likely to be the only method to systematically gather data relevant to this population.