Autoimmunity and Novel Therapies in Immune-Mediated Thrombocytopenia

Primary Immune Thrombocytopenic Purpura (ITP) and ITP Associated with Systemic Lupus Erythematosus: A Review of Clinical Characteristics and Treatment Modalities

Immune thrombocytopenic purpura (ITP) is an immune-mediated disorder characterized by the destruction of platelets and megakaryocytes due to autoantibodies against the platelet surface proteins. ITP without any apparent cause of thrombocytopenia is defined as primary ITP, and ITP in the setting of SLE is secondary ITP, which can be diagnosed after excluding other causes of thrombocytopenia by history, physical examination, and laboratory testing. Patients with ITP associated with SLE have higher median platelet count and less bleeding manifestations compared to the patients with primary ITP. It can be very challenging to diagnose primary ITP in SLE patients as other causes of thrombocytopenia including drug-induced thrombocytopenia, antiphospholipid syndrome, and thrombotic microangiopathic process should be ruled out. Corticosteroids are the main modality of treatment. IVIG can be used in severe cases. Splenectomy was found to be less effective in ITP associated with SLE compared to primary ITP. Control of disease activity with immunosuppressive therapy can be helpful in some cases associated with active disease flares in SLE patients.

Early diagnosis and clinical application of systemic lupus erythematosus based on a nomogram model

Systemic lupus erythematosus (SLE) is a chronic autoimmune disease involving multi-system and multi-organ dysfunction, and is easily misdiagnosed early in the disease course. We aimed to accurately predict early SLE nomogram to provide a reference basis for the early clinical diagnosis of SLE. Methods: We retrospectively analyzed 167 patients who were first diagnosed with SLE at Fengxian District Central Hospital, Shanghai, between March 2017 and October 2022. Three groups of 129 physically healthy subjects, 67 patients with rheumatoid arthritis, and 40 patients with rashes were selected as controls during the same period. Patients with SLE and control group were randomly divided into training (n = 217) and validation (n = 141) group. Univariate and multivariate analyses were used to identify independent risk factors for early SLE diagnosis. The independent risk factors for diagnosis were used to construct a nomogram to predict early SLE. Results: Based on the training group, three variables were identified as independently influencing early SLE: platelets (odds ratio OR = 0.993, P = 0.047), albumin (OR = 0.833, P = 0.007), and complement component 1q (OR = 0.956, P = 0.000). The precision of the nomogram was assessed using C-index values and calibration plot diagrams. The C-index values were 0.929 for training group and 0.898 for validation group. Both the training group and validation group calibration curves showed good predicted outcomes. Conclusion: The construction of a nomogram can accurately predict the risk of early SLE. The model showed good discriminatory power and calibration for use in the diagnosis of SLE, providing a visual tool and reference basis for the early diagnosis of SLE.

Toxicity spectrum and risk factors for chemo-immunotherapy in locally advanced or metastatic lung cancer

Chemo-immunotherapy has become the best first-line treatment for advanced lung cancer patients without oncogenic drivers. However, it may also lead to an increased incidence and severity of treatment-related adverse events. In this retrospective study, lung cancer patients administrated with either anti-PD-1 or anti-PD-L1 treatment plus chemotherapy were included. Data on demographic characteristics, disease characteristics, treatment strategies, laboratory results, and clinical outcomes were collected from the Electronic Medical Records System and evaluation scales. Chi-square, univariate, and multivariate logistic regression analyses were used to identify the risk factors for immune-related adverse events (irAEs). A total of 116 patients were included in the study, and the majority experienced treatment-related adverse events. Adverse events of any grade were reported in 114 (98.3%) patients, with 73 (62.9%) experiencing Grade 3 or higher events. The most frequent adverse events were anemia (67.2%), decreased appetite (62.9%), and alopecia (53.4%). Fifty-four (46.6%) patients were diagnosed with irAEs, with hypothyroidism (28.4%) being the most commonly reported. Multivariable analysis demonstrated a significant correlation between the number of treatment cycles, elevated baseline levels of thyroid stimulating hormone (TSH) and interleukin-6 (IL-6) with irAEs (OR = 1.222, P = 0.009, OR = 1.945, P = 0.016, OR = 1.176, P = 0.004), and IL-6 was identified as a strong predictor of severe irAEs (OR = 1.084, P = 0.014). Our study demonstrated the safety of chemo-immunotherapy in lung cancer patients without additional toxicity. The number of treatment cycles, higher baseline levels of TSH and IL-6 were identified as potential clinical biomarkers for irAEs.

Assessment of plasmablast cells in immune thrombocytopenic purpura in children

Primary immune thrombocytopenic purpura (ITP) is an autoimmune disorder with platelet destruction due to B- and T-cell dysregulation and antiplatelet autoantibodies production. Flow cytometry can be used to further characterize the B- and T-cell compartments involved in platelet destruction. This case-control study was to enumerate plasmablast cells in pediatric ITP patients and to correlate their levels with disease course. This study included 30 ITP patients and 10 controls. Identification and enumeration of Plasmablast were done by multicolor flow cytometry using specific antibody panels (CD19, CD27 & CD38) and sequential gating using FACSCanto flow cytometer and FlowJo software. We found that lymphocytes subpopulation in ITP patients and controls revealed increase in frequency of CD19 (B lymphocytes) in acute, persistent, and chronic ITP patients in comparison with controls (p < 0.001, 0.023, 0.001) respectively. Plasmablast cells could play a role in the pathogenesis of ITP and might guide therapy in ITP patients in the future.

Potential risk factors for the development from immune thrombocytopenia to systemic lupus erythematosus: a case-control study in Chinese children

Immune thrombocytopenia (ITP) patients are at risk developing to systemic lupus erythematosus (SLE) in the future. Our study attempted to explore the potential risk factors for the development from ITP to SLE in Chinese children by statistical analysis. This study was a retrospective case-control study. Patients diagnosed with ITP and developed to SLE after the diagnosis of ITP were defined as the case group. The control group consisted of children with ITP but without developing to SLE was recruited with a ratio of 1:2. Besides univariable analysis, multivariable logistic regression was built to evaluate the potential risk factors. A total of 150 children was included with 50 in the case group and 100 in the control group. Median developing time from ITP to SLE was 34.5 [IQR 12.5, 58.75] months. ANA was found significantly different between the two groups in our study in the univariable analysis but not in the multivariable analysis (OR = 4.50, 95% CI 0.97 to 21.01). Age diagnosed ITP was positively associated with SLE (OR = 1.07 every 5 years, 95% CI 1.01 to 1.15) with alert point at 8 years old (sensitivity 0.82, specificity 0.60). A lower level of complement was also positively associated with SLE (OR = 8.33, 95% CI 1.62 to 42.91). A minimum 3-year of close follow-up for pediatric ITP patients was recommended to monitor the risk for developing SLE. Older age and hypocomplementemia were potential risk factors for the development from ITP to SLE.

Sirolimus for patients with connective tissue disease-related refractory thrombocytopenia: a single-arm, open-label clinical trial

OBJECTIVES

Connective tissue disease-related thrombocytopenia (CTD-TP) is a problematic disorder in clinical practice. Because the first-line therapy of glucocorticoid and/or immunosuppressants is not effective for refractory cases, alternative treatment approaches are urgently needed. The present study investigated the efficacy and safety of sirolimus in refractory CTD-TP patients.

METHODS

This single-centre, single-arm, phase II study enrolled 20 refractory CTD-TP patients between September 2017 and September 2018 (registered on ClinicalTrials.gov: NCT03688191). Oral sirolimus administration was dose-adjusted to maintain a therapeutic range of 6-15 ng/ml for 6 months. The primary endpoints were partial and complete remission rates at 6 months.

RESULTS

Twelve (60%) patients achieved the primary end point with a 50% complete remission rate after 6 months. Among the 14 SLE patients, the overall response rate was 71.4%, with a complete remission rate of 64.3%. None of the primary Sjögren's syndrome cases responded to sirolimus. There was no significant difference in baseline clinical characteristics or lymphocyte subpopulations between responders and non-responders. No severe side effect was detected during the study.

CONCLUSION

Sirolimus is an effective and safe treatment option for refractory CTD-TP patients.

TRIAL REGISTRATION

https://clinicaltrials.gov, NCT03688191.

Prevalence and influential factors of thrombocytopaenia in systemic lupus erythematosus patients: a retrospective analysis of 3140 cases in a Chinese population

Introduction

The present study aimed to investigate the prevalence and influential factors of thrombocytopaenia in systemic lupus erythematosus (SLE) patients among the Chinese population in order to provide evidence for improving the treatment and nursing of SLE patients.

Methods

A retrospective analysis of 3140 SLE patients admitted to two large tertiary hospitals was conducted in Anhui, China, from 2011 to 2018. In addition, the influential factors related to SLE with thrombocytopaenia were analysed through univariate and multivariate analysis.

Results

A total of 804 SLE patients had thrombocytopaenia (25.6%). The top 5 clinical manifestations of SLE inpatients were proteinuria (51.0%), lupus nephritis (45.9%), new rash (38.4%), haematuria (36.7%) and pyuria (32.2%). The incidence of neurological manifestations, oral mucosal ulceration, pleurisy, pericarditis, hyperglycaemia, leucocytopaenia, urinary casts, haematuria, pyuria and high disease activity in the thrombocytopaenia group were higher than those in the non-thrombocytopaenia group ( p < 0.05). Multivariate analysis showed age (odds ratio (OR) = 1.009, p = 0.005), neurological manifestations (OR = 1.373, p = 0.048), pericarditis (OR = 1.394, p = 0.048), hyperglycaemia (OR = 1.717, p < 0.001), leucocytopaenia (OR = 2.551, p < 0.001), haematuria (OR = 1.582, p < 0.001), serum C3 level <0.85 g/L (OR = 1.525, p = 0.001), serum C4 concentration <0.10 g/L (OR = 1.287, p = 0.020), serum CRP concentration <8 ng/L (OR = 1.314, p = 0.005), prothrombin time >15.30 seconds (OR = 1.479, p = 0.032), activated partial thromboplatin time >45 seconds (OR = 1.924, p < 0.001) and thrombin time >21 seconds (OR = 1.629, p = 0.015) were associated with thrombocytopaenia.

Conclusion

Thrombocytopaenia has a high prevalence in SLE patients and is related to some baseline, clinical and laboratory characteristics, affecting multiple organs and systems.

Thrombocytopenia as a Prognostic Marker for Systemic Lupus Erythematosus: A Systematic Review and Meta-analysis

BACKGROUND

Systemic lupus erythematosus (SLE) patients often exhibit hematological abnormalities, but the role of thrombocytopenia on the prognosis of SLE shows inconsistent results. The purpose of this meta-analysis was to confirm the impact of thrombocytopenia on mortality and end organ damage in patients with SLE.

MATERIALS AND METHODS

Three electronic databases, PubMed, Embase and Cochrane library were systematically searched to identify the eligible studies from inception to November 2017 in order to evaluate the impact of thrombocytopenia on the prognosis of patients with SLE. The summary odds ratios (ORs) and 95% confidence intervals (CIs) were used to measure the impact of thrombocytopenia on mortality and end organ damage based on the random-effects model.

RESULTS

A total of 8 studies that reported data on 2,158 patients with SLE were included. The summary OR indicated that SLE subjects with thrombocytopenia were significantly associated with an increased risk of mortality (OR: 4.57; 95% CI: 2.28-9.17; P < 0.001) and end-organ damage (OR: 3.31; 95% CI: 1.11-9.86; P = 0.031). Furthermore, the sensitivity analysis indicated stable mortality, while the result for end organ damage was variable. In addition, the patients with thrombocytopenia with disease duration <60 months presented a greater risk for mortality than those with disease duration ≥60.0 months (P = 0.002).

CONCLUSIONS

Patients with SLE and thrombocytopenia were found to be associated with an increased risk of mortality and end organ damage.

Identification of novel autoantigens via mass spectroscopy-based antibody-mediated identification of autoantigens (MS-AMIDA) using immune thrombocytopenic purpura (ITP) as a model disease

Immune thrombocytopenic purpura (ITP) is one of the best characterized autoimmune diseases. Autoantibodies (AABs) against platelet antigens are considered as the diagnostic hallmark of ITP, but are detectable in only 50% of patients. We designed and applied a novel proteomic approach termed Mass Spectroscopy-based Antibody-Mediated Identification of Autoantigens (MS-AMIDA) for platelet antigens. Patients were separated into patients with classical AABs [ITP(+)] and patients without AABs [ITP(-)]. Altogether, 181 potential AAGs were found in ITP(+) and 135 AAGs in ITP(-), with 34 and 23 AAGs reproducibly found in two runs of MS-AMIDA. After subtracting identifiers from the controls, 57 AAGs in ITP(+) and 29 AAGs in ITP(+) remained, with 16 AAGs commonly found in ITP(+) and ITP(-) patients. Label-free quantification (LFQ) revealed 15 potential AAGs that are quantitatively stronger in ITP. Dot blot validation was performed on hexokinase 1 (HK1), E1 pyruvate dehydrogenase (E1-PDH), coagulation factor XIII, filamin A (FLNA), non-muscle myosin 9. Eleven patients were found to have anti-HK1 AABs, one patient had anti-E1-PDH AABs, and two patients had anti-FLNA AABs. Most antigens were of intracellular origin with significant association with actin-cytoskeleton and regulation of programmed cell death. In conclusion, novel AAGs for ITP were identified using MS-AMIDA.

Prognostic significance of platelet count in SLE patients

Hematological abnormalities, especially thrombocytopenia (TCP), are highly prevalent among patients with systemic lupus erythematosus (SLE) and at the same time it has been reported as a significant prognostic factor of SLE course. We further investigate the correlation between platelet count and the clinical manifestations and disease activity of SLE, in a cohort of Saudi Arabian female patients. A retrospective analysis was done for the medical records of 100 SLE female patients, selected from all patients diagnosed and treated for SLE at the Rheumatology outpatient clinics in Hera'a General Hospital, Holly Makkah, Saudi Arabia. The data collected from every patient's file included laboratory investigations (complete blood count, platelet parameters, ESR, anti-double-stranded DNA antibody, ANA), clinical manifestations, as well as SLE disease activity index (SLEDAI-2k) scores throughout a period of six sequential follow-up visits. Patients were divided into three groups according to the SLEDAI-2k: mild, moderate, and high-activity group. We found that, out of 100 patients, TCP was the most prevalent hematological abnormality evident in 15%, more than leucopenia (14%) and anemia (2%). TCP was acute in onset and associated with arthritis, neurologic manifestations, and nephritis. Platelet count showed a significant negative correlation with disease activity, in all of the three groups of patients. We concluded that platelet count has a negative correlation with disease activity in SLE patients, whatever the associated manifestations, and it should be considered as a prognostic factor, identifying patients with aggressive disease course.

Tolerability and Efficacy of Eltrombopag in Chronic Immune Thrombocytopenia: Meta-Analysis of Randomized Controlled Trials

BACKGROUND

Eltrombopag is an oral thrombopoietin receptor agonist that stimulates the production of normally functioning platelets. The aim of this meta-analysis is to synthesize evidence about the safety and efficacy of eltrombopag for both adult and children with primary immune thrombocytopenia (ITP).

METHODS

A computer literature search of PubMed, Scopus, Web of Science, and Cochrane Central was conducted. Records were screened for eligible studies, and data were extracted and synthesized using Review Manager for Windows. Subgroup analysis and sensitivity analysis were conducted to investigate whether treatment effect varies significantly between adults and children.

RESULTS

Six randomized controlled trials (N = 611 patients) were included in the final analysis. The overall effect estimates favored eltrombopag group in terms of overall platelet response (relative risk [RR]: 3.42; 95% confidence interval [CI]: 2.51-4.65; P < .0001), incidence of significant bleeding (RR: 0.56; 95% CI: 0.41-0.77; P = .0004), and number of cases needed to rescue treatment (RR: 0.45; 95% CI: 0.32-0.65; P < .0001). The efficacy of eltrombopag did not differ significantly between children and adults except for incidence of any bleeding (RR: 0.83 vs 0.51; P = .008).

CONCLUSION

Eltrombopag is a tolerable and effective drug for the management of chronic ITP in children and adults.

Expression, purification and biological activity assessment of romiplostim biosimilar peptibody

Background

Romiplostim is a peptibody analogue of thrombopoietin (TPO) which regulates platelet production. This molecule consists of two main parts: Peptide sequences which like wild type TPO, mimics stimulation of TPO receptor and IgG1Fc, (Peptide + Antibody = Peptibody). This drug is used in treatment of chronic Immune Thrombocytopenic Purpura (ITP).

Methods

In this project E. coli bacteria were transformed by a construct harboring peptibody fusion gene. This construct consisted of two repeated peptide sequences which have fused to Carboxyl group of IgG1Fc. Designed construct in E. coli host resulted in protein expression in cytoplasm as inclusion body. The inclusion bodies were separated, washed and after denaturation and solubilization, in the last stage the desired peptibodies were refolded and purified. The resulting peptibodies were characterized by SDS-PAGE and Western immunoblotting. The bioactivity were assessed in vivo using subcutaneous injection in mice.

Results

Results showed accurate molecules were produced and purified. Also, in vivo experiment showed significant increment (more than two fold) of platelets compared to control group.

Conclusion

In this study laboratory scale production of recombinant romiplostim showed proper in-vivo bioactivity. This new approach in expression and purification of this recently introduced thrombopoietin receptor agonist drug may be followed by scale up of its production to response the chronic ITP patient’s demand.

Identification of novel biomarkers in chronic immune thrombocytopenia (ITP) by microarray-based serum protein profiling

The pathological mechanisms underlying the development of immune thrombocytopenia (ITP) are unclear and its diagnosis remains a process of exclusion. Currently, there are no known specific biomarkers for ITP to support differential diagnosis and treatment decisions. Profiling of serum proteins may be valuable for identifying such biomarkers. Sera from 46 patients with primary chronic ITP and 34 healthy blood donors were analysed using a microarray of 755 antibodies. We identified 161 differentially expressed proteins. In addition to oncoproteins and tumour-suppressor proteins, including apoptosis regulator BCL2, breast cancer type 1 susceptibility protein (BRCA1), Fanconi anaemia complementation group C (FANCC) and vascular endothelial growth factor A (VEGFA), we detected six anti-nuclear autoantibodies in a subset of ITP patients: anti-PCNA, anti-SmD, anti-Ro/SSA60, anti-Ro/SSA52, anti-La/SSB and anti-RNPC antibodies. This finding may provide a rational explanation for the association of ITP with malignancies and other autoimmune diseases. While RUNX1mRNA expression in the peripheral blood mononuclear cells (PBMC) of patients was significantly downregulated, an accumulation of RUNX1 protein was observed in the platelets of ITP patients. This may indicate dysregulation of RUNX1 expression in PBMC and megakaryocytes and may lead to an imbalanced immune response and impaired thrombopoiesis. In conclusion, we provide novel insights into the pathogenic mechanisms of ITP that warrant further exploration.

Thrombocytopenia and thrombosis: a double-edged sword

Severe thrombocytopenia with bleeding associated with a life-threatening thrombotic manifestation in the setting of antiphospholipid syndrome is a major diagnostic and therapeutic challenge for the clinician. Hemorrhage is a less common complication than thrombosis in patients with APS, although severe thrombocytopenia can sometimes result in bleeding. There are no evidence-based guidelines regarding the management of a patient with severe thrombocytopenia associated with a major thrombotic manifestation. In this case report, we review the literature reporting the difficulties in management of such patient.