Platelet-rich plasma: a narrative review
EFORT open reviews. 2021;6(4):225-235
The aim of this article was to synopsize platelet-rich plasma (PRP) use in musculoskeletal pathologies through evidence-based assessment of the preparation, classification, mechanism of action and applications of PRP, thereby answering which PRP type is best for each clinical indication.The literature search was performed using Medline, EMBASE and Cochrane Reviews databases for papers containing the key terms "platelet-rich plasma" AND "orthopaedics" AND ("classification" OR "mechanism of action" OR "preparation" OR "clinical application"). Generated papers were evaluated for pertinence in following areas: preparation, classification, mechanism of action, clinical application within orthopaedics. Non-English papers were excluded. Included studies were evaluated for quality.Sixty studies were included in our review. There are many commercial PRP preparation kits with differing component concentrations. There is no consensus on optimal component concentrations. Multiple PRP classifications exist but none have been validated. Platelet-rich plasma acts via growth factors (GFs) released from α-granules within platelets. Growth factors have been shown to be beneficial in healing. Grossly elevated concentrations of GFs may have inhibitory effects on healing. Multiple systematic reviews show efficacy of PRP in tendinopathies, early osteoarthritis, acute muscle injuries and in combination with rotator cuff repair and anterior cruciate ligament reconstruction.The literature suggests leukocyte-rich PRP (L-PRP) is more beneficial in tendinopathies and pure PRP (P-PRP) is more beneficial in cartilage pathology. However, different PRP preparations have not been directly compared in any pathology. Classification of PRP type is frequently not stated in research. Standardization of PRP research parameters is needed to streamline findings and generate clear indications for PRP types to yield maximum clinical benefit. Cite this article: EFORT Open Rev 2021;6:225-235. DOI: 10.1302/2058-5241.6.200017.
Efficacy of convalescent plasma for the treatment of severe influenza
Crit Care. 2020;24(1):469
BACKGROUND Convalescent plasma administration may be of clinical benefit in patients with severe influenza, but reports on the efficacy of this therapy vary. METHODS We conducted a systematic review and meta-analysis assessing randomized controlled trials (RCTs) involving the administration of convalescent plasma to treat severe influenza. Healthcare databases were searched in February 2020. All records were screened against eligibility criteria, and the risks of bias were assessed. The primary outcome was the fatality rate. RESULTS A total of 2861 studies were retrieved and screened. Five eligible RCTs were identified. Pooled analyses yielded no evidence that using convalescent plasma to treat severe influenza resulted in significant reductions in mortality (odds ratio, 1.06; 95% CI, 0.51-2·23; P = 0.87; I(2) = 35%), number of days in the intensive care unit, or number of days on mechanical ventilation. This treatment may have the possible benefits of increasing hemagglutination inhibition titers and reducing influenza B viral loads and cytokine levels. No serious adverse events were reported. The included studies were generally of high quality with a low risk of bias. CONCLUSIONS The administration of convalescent plasma appears safe but may not reduce the mortality, number of days in the intensive care unit, or number of days on mechanical ventilation in patients with severe influenza.
Interventions for renal vasculitis in adults
Patients hospitalized with severe influenza (5 studies, n= 598).
Convalescent plasma or hyperimmune intravenous immunoglobulin (H-IVIG).
Various comparators (normal intravenous immunoglobulin, standard care, low-titre anti-influenza, placebo).
Pooled analyses yielded no evidence that using convalescent plasma to treat severe influenza resulted in significant reductions in mortality, number of days in the intensive care unit, or number of days on mechanical ventilation.
The Cochrane database of systematic reviews. 2020;1:Cd003232
BACKGROUND Renal vasculitis presents as rapidly progressive glomerulonephritis and comprises of a group of conditions characterised by acute kidney injury (AKI), haematuria and proteinuria. Treatment of these conditions involve the use of steroid and non-steroid agents in combination with plasma exchange. Although immunosuppression overall has been very successful in treatment of these conditions, many questions remain unanswered in terms of dose and duration of therapy, the use of plasma exchange and the role of new therapies. This 2019 publication is an update of a review first published in 2008 and updated in 2015. OBJECTIVES To evaluate the benefits and harms of any intervention used for the treatment of renal vasculitis in adults. SEARCH METHODS We searched the Cochrane Kidney and Transplant Register of Studies up to 21 November 2019 through contact with the Information Specialist using search terms relevant to this review. Studies in the Register are identified through searches of CENTRAL, MEDLINE, and EMBASE, conference proceedings, the International Clinical Trials Register (ICTRP) Search Portal and ClinicalTrials.gov. SELECTION CRITERIA Randomised controlled trials investigating any intervention for the treatment of renal vasculitis in adults. DATA COLLECTION AND ANALYSIS Two authors independently assessed study quality and extracted data. Statistical analyses were performed using a random effects model and results expressed as risk ratio (RR) with 95% confidence intervals (CI) for dichotomous outcomes or mean difference (MD) for continuous outcomes. MAIN RESULTS Forty studies (3764 patients) were included. Studies conducted earlier tended to have a higher risk of bias due to poor (or poorly reported) study design, broad inclusion criteria, less well developed disease definitions and low patient numbers. Later studies tend to have improved in all areas of quality, aided by the development of large international study groups. Induction therapy: Plasma exchange as adjunctive therapy may reduce the need for dialysis at three (2 studies: RR 0.43, 95% CI 0.23 to 0.78; I(2) = 0%) and 12 months (6 studies: RR 0.45, 95% CI 0.29 to 0.72; I(2) = 0%) (low certainty evidence). Plasma exchange may make little or no difference to death, serum creatinine (SCr), sustained remission or to serious or the total number of adverse events. Plasma exchange may increase the number of serious infections (5 studies: RR 1.26, 95% CI 1.03 to 1.54; I(2) = 0%; low certainty evidence). Remission rates for pulse versus continuous cyclophosphamide (CPA) were equivalent but pulse treatment may increase the risk of relapse (4 studies: RR 1.79, 95% CI 1.11 to 2.87; I(2) = 0%) (low certainty evidence) compared with continuous cyclophosphamide. Pulse CPA may make little or no difference to death at final follow-up, or SCr at any time point. More patients required dialysis in the pulse CPA group. Leukopenia was less common with pulse treatment; however, nausea was more common. Rituximab compared to CPA probably makes little or no difference to death, remission, relapse, severe adverse events, serious infections, or severe adverse events. Kidney function and dialysis were not reported. A single study reported no difference in the number of deaths, need for dialysis, or adverse events between mycophenolate mofetil (MMF) and CPA. Remission was reported to improve with MMF however more patients relapsed. A lower dose of steroids was probably as effective as high dose and may be safer, causing fewer infections; kidney function and relapse were not reported. There was little of no difference in death or remission between six and 12 pulses of CPA. There is low certainty evidence that there were less relapses with 12 pulses (2 studies: RR 1.57, 95% CI 0.96 to 2.56; I(2) = 0%), but more infections (2 studies: RR 0.79, 95% CI 0.36 to 1.72; I(2) = 45%). One study reported severe adverse events were less in patients receiving six compared to 12 pulses of CPA. Kidney function and dialysis were not reported. There is limited evidence from single studies about the effectiveness of intravenous immunoglobulin, avacopan, methotrexate, immunoadsorption, lymphocytapheresis, or etanercept. Maintenance therapy: Azathioprine (AZA) has equivalent efficacy as a maintenance agent to CPA with fewer episodes of leucopenia. MMF resulted in a higher relapse rate when tested against azathioprine in remission maintenance. Rituximab is an effective remission induction and maintenance agent. Oral co-trimoxazole did not reduce relapses in granulomatosis with polyangiitis. There were fewer relapses but more serious adverse events with leflunomide compared to methotrexate. There is limited evidence from single studies about the effectiveness of methotrexate versus CPA or AZA, cyclosporin versus CPA, extended versus standard AZA, and belimumab. AUTHORS' CONCLUSIONS Plasma exchange was effective in patients with severe AKI secondary to vasculitis. Pulse cyclophosphamide may result in an increased risk of relapse when compared to continuous oral use but a reduced total dose. Whilst CPA is standard induction treatment, rituximab and MMF were also effective. AZA, methotrexate and leflunomide were effective as maintenance therapy. Further studies are required to more clearly delineate the appropriate place of newer agents within an evidence-based therapeutic strategy.
Plasma D-Dimer Concentrations and Risk of Intracerebral Hemorrhage: A Systematic Review and Meta-Analysis
Frontiers in neurology. 2018;9:1114
Background: The aim of our meta-analysis was to evaluate the association between plasma d-dimer and intracerebral hemorrhage (ICH). Methods: Embase, Pubmed, and Web of Science were searched up to the date of March 19th, 2018, and manual searching was used to extract additional articles. Standard mean difference (SMD) with 95% confidence intervals (CI) was calculated to evaluate d-dimer levels. Results: Thirteen studies including 891 ICH patients and 1,573 healthy controls were included. Our results revealed that higher levels of d-dimer were displayed in ICH patients than those in healthy controls (95% CI= 0.98-2.00, p< 0.001). Subgroup analysis based on continent of Asia and Europe, sample size, as well as age in relation to d-dimer levels between ICH patients and healthy controls did not change the initial observation; whereas no differences of d-dimer levels were found between ICH and controls in America. Conclusions: This meta-analysis revealed that high level of d-dimer is associated with the risk of ICH. Plasma d-dimer is suggested to be a potential biomarker for patients with ICH in Asia and Europe rather than in America. There were no impact of sample size-related differences and age-related diversities on the risk of ICH with respect to d-dimer levels.
The effectiveness of convalescent plasma and hyperimmune immunoglobulin for the treatment of severe acute respiratory infections of viral etiology: a systematic review and exploratory meta-analysis
Journal of Infectious Diseases. 2015;211((1):):80-90.
BACKGROUND Administration of convalescent plasma, serum, or hyperimmune immunoglobulin may be of clinical benefit for treatment of severe acute respiratory infections (SARIs) of viral etiology. We conducted a systematic review and exploratory meta-analysis to assess the overall evidence. METHODS Healthcare databases and sources of grey literature were searched in July 2013. All records were screened against the protocol eligibility criteria, using a 3-stage process. Data extraction and risk of bias assessments were undertaken. RESULTS We identified 32 studies of SARS coronavirus infection and severe influenza. Narrative analyses revealed consistent evidence for a reduction in mortality, especially when convalescent plasma is administered early after symptom onset. Exploratory post hoc meta-analysis showed a statistically significant reduction in the pooled odds of mortality following treatment, compared with placebo or no therapy (odds ratio, 0.25; 95% confidence interval, .14-.45; I(2) = 0%). Studies were commonly of low or very low quality, lacked control groups, and at moderate or high risk of bias. Sources of clinical and methodological heterogeneity were identified. CONCLUSIONS Convalescent plasma may reduce mortality and appears safe. This therapy should be studied within the context of a well-designed clinical trial or other formal evaluation, including for treatment of Middle East respiratory syndrome coronavirus CoV infection. The Author 2014. Published by Oxford University Press on behalf of the Infectious Diseases Society of America.