An evaluation of the association of leukopenia and severe infection in patients with systemic lupus erythematosus

Evaluation of immune profiles associated with control of mycobacterial growth in systemic lupus erythematosus (SLE) patients

Tuberculosis (TB) is an infectious disease with the burden concentrated in low- and middle-income countries. Systemic lupus erythematosus (SLE) is an autoimmune disease associated with widespread inflammation that is prevalent in some TB endemic areas including East Africa and parts of Southeast Asia. SLE patients are known to be at higher risk of becoming infected with M. tb, developing TB disease. However, the immune mechanisms underlying this susceptibility are not well understood, particularly in the absence of immunosuppressive drugs. We present a pilot study in which we have evaluated intracellular cytokine responses and ex vivo ability to control mycobacterial growth using peripheral blood mononuclear cells (PBMC) collected from SLE patients before and during SLE treatment. After six months of treatment, SLE patients had the highest frequencies of CD8+ T cells, NK cells and NKT cells producing IFN-γ and/or TNF-α. This group also showed superior control of mycobacterial growth, and proinflammatory cytokine-producing NK and NKT cells correlated with mycobacterial growth inhibition at the individual patient level. These findings contribute to a better understanding of autoimmune profiles associated with control of mycobacterial growth in SLE patients, which may inform intervention strategies to reduce risk of TB disease in this population.

Risk stratification for infection during immunosuppressive therapy in patients with lupus nephritis: A nested case-control study

BACKGROUND

The current prediction models for the risk of infection during immunosuppressive treatment for lupus nephritis (LN) lack a prediction time window and have poor pertinence. This study aimed to develop a risk stratification to predict infection during immunosuppressive therapy in patients with LN.

METHODS

This retrospective nested case-control study collected patients with LN treated with immunosuppressive therapy between 2014 and 2022 in the Nephrology ward in Huashan Hospital affiliated to Fudan University and Huashan Hospital Baoshan Branch. Cases were defined as patients who experienced infection during the follow-up period; patients were eligible as controls if they did not have infection during the follow-up period.

RESULTS

There were 53 patients with infection by CTCAE V5.0 grade ≥2. According to the 1:3 nested matching, the 53 patients with infection were matched with 159 controls. In the multivariable logistic regression model, the change rate of fibrinogen (OR = 0.97, 95% CI: 0.94-0.99, p = 0.008), leukopenia (OR = 8.68, 95% CI: 1.16-301.72, p = 0.039), and reduced albumin (OR = 6.25, 95% CI: 1.38-28.24, p = 0.017) were independently associated with infection. The AUC of the ROC curve in the validation set of the multivariable logistic regression model in the internal random sampling was 0.864. The scores range from -2 to 10. The infection risk stratification ranges from 2.8% at score -2 to 97.5% at score 10.

CONCLUSION

A risk stratification was built to predict the risk of infection in patients with LN undergoing immunosuppressive therapy.

Association Between Mycophenolate Mofetil Use and Subsequent Infections Among Hospitalized Patients with Systemic Lupus Erythematosus: A Nested Case-Control Study

INTRODUCTION

The association between mycophenolate mofetil (MMF) and infection in patients with systemic lupus erythematosus (SLE) has not been clarified. This study evaluated the degree and factors in effect of MMF use on infection in patients with SLE.

METHODS

A hospitalized-based observational study was conducted to collect medical records on patients with SLE during 2010-2021. A nested case-control study was performed among 3339 patients with SLE, including 1577 cases and 1762 controls by whether they developed any type of infection. The exposure of MMF use was determined within 1 year before diagnosed infection or the end of follow-up. Logistic regression was used to estimate the odds ratio (OR) and 95% confidence interval (CI) for association between MMF and subsequent infection.

RESULTS

MMF was significantly associated with the risk of overall infection (adjusted OR 1.90, 95% CI 1.48-2.44) and different types of infections, including bacterial infection (adjusted OR 2.07, 95% CI 1.55-2.75), viral infection (adjusted OR 1.92, 95% CI 1.23-3.01), and opportunistic infection (adjusted OR 2.13, 95% CI 1.31-3.46). The top three risks of specific types of infections were bacteremia/septicemia, urinary tract infection/pyelonephritis, and herpes zoster. Stratification analysis showed risk of overall infection increased especially in MMF users with age over 55 years, diabetes, central nervous system involvement, and thrombocytopenia. Moreover, the risk of infection increased with increasing dosage and duration of MMF use. Additionally, the combination of MMF with CYC and other immunosuppressants significantly increases the risk of infections compared to using a single one.

CONCLUSIONS

MMF use is associated with various type of infections in patients with SLE, particularly in those with longer use, older age, complications with comorbidities, and concomitant use of CYC or other immunosuppressants.

Major infections in newly diagnosed systemic lupus erythematosus: an inception cohort study

Objective

To evaluate the risk of major infections and the relationship between major infections and mortality in patients with newly diagnosed SLE.

Methods

A newly diagnosed (<3 months) hospitalised Systemic Lupus Inception Cohort (hSLIC) in our centre during 1 January 2013 and 1 November 2020 was established. All patients were followed up for at least 1 year or until death. Patient baseline characteristics were collected. Major infection events were recorded during follow-up, which were defined as microbiological/clinical-based diagnosis treated with intravenous antimicrobials. The cohort was further divided into a training set and a testing set. Independent predictors of major infections were identified using multivariable logistic regression analysis. Kaplan-Meier survival analyses were conducted.

Results

Among the 494 patients enrolled in the hSLIC cohort, there were 69 documented episodes of major infections during the first year of follow-up in 67 (14%) patients. The major infection events predominantly occurred within the first 4 months since enrolment (94%, 65/69) and were associated with all-cause mortality. After adjustments for glucocorticoid and immunosuppressant exposure, a prediction model based on SLE Disease Activity Index >10, peripheral lymphocyte count <0.8×10⁹/L and serum creatinine >104 µmol/L was established to identify patients at low risk (3%–5%) or high risk (37%–39%) of major infections within the first 4 months.

Conclusions

Newly onset active SLE is susceptible to major infections, which is probably due to underlying profound immune disturbance. Identifying high-risk patients using an appropriate prediction tool might lead to better tailored management and better outcome.

Hematological involvement in pediatric systemic lupus erythematosus: A multi-center study

Introduction: Systemic lupus erythematosus (SLE) may present with features of several systems, including hematological manifestations. In this study, we aimed to evaluate the characteristics of hematological involvement and assess possible associations and correlations in pediatric SLE patients. Method: This is a retrospective multi-center study. The medical records of pediatric SLE patients followed between January 2000 and June 2020 were analyzed. All children fulfilled the criteria of the Systemic Lupus International Collaborating Clinics. Results: The study included 215 children with SLE, 118 of whom had hematological manifestations. Concomitant renal involvement and low C3 levels were significantly more frequent in patients with hematological involvement (p = 0.04, p = 0.008, respectively). Also, anti-cardiolipin, anti-beta-2-glycoprotein I (anti-β2 GP1), and anti-Sm antibody positivity, and the presence of lupus anticoagulant were more common in the group with hematological findings (p = 0.001 for anti-cardiolipin antibody positivity and p < 0.001 for the positivity of anti-β2 GP1 antibody, anti-Sm antibody, and lupus anticoagulant). The most common hematologic abnormality was anemia (n = 88, 74.5%), with autoimmune hemolytic anemia constituting the majority (n = 40). Corticosteroids followed by IVIG were the mainstay of treatment. In patients resistant to corticosteroid and IVIG treatments, the most preferred drug was rituximab. Low levels of C3, high SLEDAI score, high incidence of renal involvement, and positive antiphospholipid antibodies were associated with hematological involvement in the univariate analysis. The presence of antiphospholipid antibodies and high SLEDAI score were independently associated with hematological involvement in multivariate analysis (OR: 4.021; 95% CI: 2.041-7.921; p < 0.001 and OR: 1.136; 95% CI: 1.065-1.212; p < 0.001). Conclusion: Hematological abnormalities are frequently encountered in pediatric SLE. Positive antiphospholipid antibodies and high SLEDAI scores were associated with hematological involvement.

A Prospective Study of Cytomegalovirus-Specific Cell-Mediated Immune Monitoring and Cytomegalovirus Infection in Patients With Active Systemic Lupus Erythematosus Receiving Immunosuppressants

Background

The effects of cytomegalovirus (CMV)-specific cell-mediated immunity (CMI) on CMV infection in patients with autoimmune diseases receiving immunosuppressants have not been explored.

Methods

Patients with active systemic lupus erythematosus (SLE) were preemptively monitored for clinically significant CMV infection (CsCMVI; defined as plasma CMV DNA loads >3 log10 IU/mL). CMV-specific CMI was assessed using an enzyme-linked immunosorbent assay (QuantiFERON-CMV [QF]) before as well as 1 and 3 months after intense immunosuppressive therapy.

Results

The study included 55 patients with active SLE; patients were a mean age (SD) of 34 (13) years and had a median SLE Disease Activity Index 2000 score (SD) of 14 (8), and 93% were female. Most patients had renal involvement (67%), received methylprednisolone (93%), and were CMV-seropositive (95%). Thirteen (23.6%) patients developed CsCMVI. Among patients with active SLE who were QF-negative (QF-) and QF-positive (QF+) before receiving immunosuppressive therapy, 28.6% and 25% developed CsCMVI, respectively (P = .69). However, 1 month postimmunosuppression, more QF- than QF+ patients developed CsCMVI (44.4% vs 11.8%; P = .03; adjusted hazard ratio, 4.97; 95% CI, 1.07-23.10; P = .04).

Conclusions

Patients with active SLE and low CMV-specific T-cell responses could develop CMV infection after receiving immunosuppressants. Further studies should focus on CMV-specific CMI among patients with autoimmune diseases.

Immunoglobulin levels in systemic lupus erythematosus: A narrative review

Immunoglobulins play a fundamental role in the protection of the human body against internal and external threats. They also contribute to the immune system homeostasis and maintenance of self-tolerance. Hypogammaglobulinemia is occasionally encountered in routine clinical practice by rheumatologists. Low levels of immunoglobulins can occur as primary or secondary issues and may predispose patients to various forms of infection. However, the impact of the low immunoglobulin level abnormality varies with the underlying condition. In this narrative review, we shed light on the overall types and functions of immunoglobulins for clinicians. We discuss important principles of immunoglobulin measurements. We then consider the primary and secondary causes of low immunoglobulins with a special focus on hypogammaglobulinemia in patients with systemic lupus erythematosus (SLE).

Clinical characteristics and risk factors of infection in patients with systemic lupus erythematosus: A systematic review and meta-analysis of observational studies

OBJECTIVE

Infection is one of the major causes of morbidity and mortality in systemic lupus erythematosus (SLE) patients. We conducted a systematic review and meta-analysis to investigate the clinical characteristics and risk factors of infection in SLE by comparing demographic factors, laboratory data, clinical features, and therapeutic factors between infection and non-infection SLE patients.

METHODS

PubMed, Embase, and Cochrane databases were searched systematically without restricting the language or year (up to September 2019) by using MeSH terms and keywords pertaining to SLE and infection. Three independent reviewers selected all observational studies based on the established inclusion criteria. Odds ratio (OR) and standardized mean difference (SMD) along with 95% confidence intervals (CI) were used and the analyses were carried out by using a random/fixed-effects model. When necessary, different subgroup and sensitivity analyses were conducted. Study quality was assessed by the modified version (nine-star scoring system) of the Newcastle-Ottawa Scale (NOS) and publication bias was evaluated by funnel plots, and Egger's and Begg's tests.

RESULTS

In total, we included 39 studies (3709 infection SLE patients and 10526 non-infection SLE patients) based on the inclusion criteria. Compared with the SLE patients without infection, we found that infected SLE patients had a significantly higher incidence rate of the following: 1) lymphopenia (OR = 2.738 95%CI (1.017-7.376), P = 0.046, I² = 81.4%), 2) thrombocytopenia (OR = 1.61 95%CI (1.4-1.85), P<0.001, I² = 0%), 3) anemia (OR = 2.294 95%CI (1.402-3.755), P = 0.001, I² = 83.0%), 4) hypoproteinemia (OR = 2.336 95%CI (1.408-3.876), P = 0.001, I² = 84.2%), 5) C3 consumed (OR = 1.890 95%CI (1.190-3.002), P = 0.007, I² = 77.4%), 6) diabetes mellitus (OR = 3.890 95%CI (2.450-6.160), P < 0.001, I² = 0%), 7) elevated creatinine (OR = 1.954 95%CI (1.646-2.320), P < 0.001, I² = 0.0%), 8) renal involvement (OR = 2.692 95%CI (2.000-3.623), P < 0.001, I² = 76.0%), 9) serositis (OR = 3.877 95%CI (0.995-15.110), P = 0.051, I² = 79.1%), and 10) use of steroid immunosuppressants (OR = 3.116 95%CI (1.959-4.957), P < 0.001, I² = 77.9%). Furthermore, infected SLE patients had a significantly higher mean dose of prednisone (SMD = 2.088 95%CI (1.196-2.981), P < 0.001, I² = 97.8%). In addition, SLE patients with infection showed a significantly lower incidence of antimalarial drug use (OR = 0.634 95%CI (0.451-0.892), P = 0.009, I² = 56.0%). Infected SLE patients had a significantly higher level of 1) 24-h urinary protein (SMD = 0.560 95%CI (0.300-0.810), P < 0.001, I² = 0%), 2) CRP (SMD = 0.437 95%CI (0.184-0.691), P = 0.001, I² = 68.6%), and 3) SLE Collaborating Clinics damage index (SDI) (SMD = 0.451 95%CI (0.238-0.664), P < 0.001, I² = 0.0%), along with a significantly lower level of albumin (SMD = -0.400 95%CI (-0.610--0.200), P < 0.001, I² = 0.0%). After adjustment for false discovery rate (FDR), lymphopenia and serositis were no longer associated with the occurrence of infection; however, the remaining factors were still associated with infection in SLE. According to the nine-star scoring system of NOS, 71.79% of the studies were considered as high methodological quality (low risk of bias). No significant publication bias, except for renal involvement, was detected from funnel plots or Egger's and Begg's test, while this publication bias of renal involvement did not impact the pooled estimates.

CONCLUSION

We identified many factors including thrombocytopenia, anemia, hypoproteinemia, hypocomplementemia, hypoalbuminemia, higher level of CRP, higher SDI score, renal involvement and diabetes mellitus that were associated with infection in SLE patients. In addition, glucocorticoids (especially high-dose) and immunosuppressants (e.g. cyclophosphamide) rendered SLE patients more susceptible to infection, while antimalarial drug administration (hydroxychloroquine) was a protective factor against infection in SLE patients. SLE patients with the above clinical characteristics and risk factors might be at high risk from infection, which might contribute to the early identification of infection in SLE patients for better prognosis.

Severe pneumonia in Chinese patients with systemic lupus erythematosus

Objective

This study aimed to investigate the clinical characteristics and risk factors associated with severe pneumonia in systemic lupus erythematosus (SLE) patients from China.

Method

We performed a retrospective study in 112 hospitalized SLE patients who had had pneumonia for 8 years. The primary outcome was severe pneumonia, followed by descriptive analysis, group comparison and bivariate analysis.

Results

A total of 28 SLE patients were diagnosed with severe pneumonia, with a ratio of 5:23 between men and women. The mean age at diagnosis was 44.36 ± 12.389 years. The median disease duration was 72 months, and the median SLE Disease Activity Index 2000 (SLEDAI 2K) score was 8. The haematological system was the most affected, with an incidence of anaemia in 85.7% of cases and thrombocytopenia in 75% of cases, followed by lupus nephritis in 50% of cases and central nervous system involvement in 10.71% of cases. Cultured sputum specimens were positive in 17 (68%) SLE patients with severe pneumonia, of whom nine (36%) were cases of fungal infection, five (20%) were cases of bacterial infection and three (12%) were cases of mixed infection. Using multivariate logistic regression analysis, we concluded that a daily dosage of prednisone (>10 mg; odds ratio (OR) = 3.193, p = 0.005), a low percentage of CD4+ T lymphocytes (OR = 0.909, p = 0.000), a high SLEDAI 2K score (OR = 1.182, p = 0.001) and anaemia (OR = 1.182, p = 0.001) were all independent risk factors for pneumonia in SLE patients, while a low percentage of CD4+ T lymphocytes (OR = 0.908, p = 0.033), a daily dose of prednisone of >10 mg (OR = 35.67, p = 0.001) were independent risk factors for severe pneumonia in SLE patients.

Conclusion

Severe pneumonia is not rare in lupus, and is associated with high mortality and poor prognosis. Monitoring CD4+ T-cell counts and giving a small dose of glucocorticoids can reduce the occurrence of severe pneumonia and improve the prognosis of patients with lupus.

Occurrence, predictors and outcome of infections at three months in hospitalized patients with SLE: A prospective study from Southern India

Prospective data on infections in systemic lupus erythematosus (SLE) from India are scarce. We studied the frequency and predictors of infections in hospitalized SLE patients. All data on infections were prospectively recorded. During the study period, 212 SLE patients (91% women) were hospitalised. Sixty-three (29.7%) had infections. The most common infections were pneumonia, skin and soft-tissue infections and urinary-tract infections. Mortality was higher in the infection group compared to the no infection group (11.1% vs. 0.7%; p=0.01). At three months, 10/63 developed another episode of infection. On logistic regression, the predictors of infection were fever [odds ratio (OR) = 4.17], vasculitis (OR = 2.64), thrombocytopaenia (OR = 3.59), presence of co-morbidities (OR = 3.59) and duration of hospital stay >11 days (OR = 3.55); p<0.001 for all. High-sensitivity CRP (hsCRP) and procalcitonin were measured in 95 patients. hsCRP was significantly higher in the infection group compared to the no infection group (median 27 vs. 6.5 mg/L; p<0.001). Procalcitonin was similar in both groups. A hsCRP of 11.5 mg/L had a sensitivity of 66.7% and specificity of 72.9% to diagnose infection. To conclude, 29.7% of Indian SLE patients who are hospitalized have infections, resulting in a significantly increased duration of hospital stay. The presence of fever and co-morbidities are predictors of infection. The role of high hsCRP to support the diagnosis of infection in SLE is once again confirmed.

Factors predictive of serious infections over time in systemic lupus erythematosus patients: data from a multi-ethnic, multi-national, Latin American lupus cohort

Aim

The aim of this study was to identify factors predictive of serious infections over time in patients with systemic lupus erythematosus (SLE).

Methods

A multi-ethnic, multi-national Latin American SLE cohort was studied. Serious infection was defined as one that required hospitalization, occurred during a hospitalization or led to death. Potential predictors included were sociodemographic factors, clinical manifestations (per organ involved, lymphopenia and leukopenia, independently) and previous infections at baseline. Disease activity (SLEDAI), damage (SLICC/ACR Damage Index), non-serious infections, glucocorticoids, antimalarials (users and non-users), and immunosuppressive drugs use; the last six variables were examined as time-dependent covariates. Cox regression models were used to evaluate the predictors of serious infections using a backward elimination procedure. Univariable and multivariable analyses were performed.

Results

Of the 1243 patients included, 1116 (89.8%) were female. The median (interquartile range) age at diagnosis and follow-up time were 27 (20–37) years and 47.8 (17.9–68.6) months, respectively. The incidence rate of serious infections was 3.8 cases per 100 person-years. Antimalarial use (hazard ratio: 0.69; 95% confidence interval (CI): 0.48–0.99; p = 0.0440) was protective, while doses of prednisone >15 and ≤60 mg/day (hazard ratio: 4.18; 95 %CI: 1.69–10.31; p = 0.0019) and >60 mg/day (hazard ratio: 4.71; 95% CI: 1.35–16.49; p = 0.0153), use of methylprednisolone pulses (hazard ratio: 1.53; 95% CI: 1.10–2.13; p = 0.0124), increase in disease activity (hazard ratio: 1.03; 95% CI: 1.01–1.04; p = 0.0016) and damage accrual (hazard ratio: 1.22; 95% CI: 1.11–1.34; p < 0.0001) were predictive factors of serious infections.

Conclusions

Over time, prednisone doses higher than 15 mg/day, use of methylprednisolone pulses, increase in disease activity and damage accrual were predictive of infections, whereas antimalarial use was protective against them in SLE patients.

T cell subsets and immunoglobulin G levels are associated with the infection status of systemic lupus erythematosus patients

Systemic lupus erythematosus (SLE) is a chronic, autoimmune disorder that affects nearly all organs and tissues. As knowledge about the mechanism of SLE has increased, some immunosuppressive agents have become routinely used in clinical care, and infections have become one of the direct causes of mortality in SLE patients. To identify the risk factors indicative of infection in SLE patients, a case control study of our hospital's medical records between 2011 and 2013 was performed. We reviewed the records of 117 SLE patients with infection and 61 SLE patients without infection. Changes in the levels of T cell subsets, immunoglobulin G (IgG), complement C3, complement C4, globulin, and anti-double-stranded DNA (anti-ds-DNA) were detected. CD4+ and CD4+/CD8+ T cell levels were significantly lower and CD8+ T cell levels were significantly greater in SLE patients with infection than in SLE patients without infection. Additionally, the concentrations of IgG in SLE patients with infection were significantly lower than those in SLE patients without infection. However, complement C3, complement C4, globulin, and anti-ds-DNA levels were not significantly different in SLE patients with and without infection. Therefore, clinical testing for T cell subsets and IgG is potentially useful for identifying the presence of infection in SLE patients and for distinguishing a lupus flare from an acute infection.

Mesenteric vasculitis after G-CSF administration in a severe neutropenic patient with systemic lupus erythematosus

Granulocyte colony-stimulating factor (G-CSF) is commonly used with neutropenic patients to accelerate recovery. G-CSF is a hematopoietic cytokine that regulates the proliferation and differentiation of neutrophil precursors, and is known as a safe and effective treatment for chemotherapy-induced neutropenia. However, we encountered a case in which a patient with systemic lupus erythematosus (SLE) developed mesenteric vasculitis after G-CSF administration. The patient was a 36-year-old female admitted with fever, arthralgia, and generalized erythematous rash. Despite symptomatic improvement with a high-dose steroid, severe neutropenia persisted for three weeks, precipitating a decision to use G-CSF to enhance recovery. Mesenteric vasculitis developed 15 hours after administration of G-CSF injection. Because the response of immune cells such as neutrophils and T cells is uncontrolled and dysfunctional in patients with lupus, G-CSF therapy should be used with caution.

High Affinity Antibodies against Influenza Characterize the Plasmablast Response in SLE Patients After Vaccination

Breakdown of B cell tolerance is a cardinal feature of systemic lupus erythematosus (SLE). Increased numbers of autoreactive mature naïve B cells have been described in SLE patients and autoantibodies have been shown to arise from autoreactive and non-autoreactive precursors. How these defects, in the regulation of B cell tolerance and selection, influence germinal center (GC) reactions that are directed towards foreign antigens has yet to be investigated. Here, we examined the characteristics of post-GC foreign antigen-specific B cells from SLE patients and healthy controls by analyzing monoclonal antibodies generated from plasmablasts induced specifically by influenza vaccination. We report that many of the SLE patients had anti-influenza antibodies with higher binding affinity and neutralization capacity than those from controls. Although overall frequencies of autoreactivity in the influenza-specific plasmablasts were similar for SLE patients and controls, the variable gene repertoire of influenza-specific plasmablasts from SLE patients was altered, with increased usage of JH6 and long heavy chain CDR3 segments. We found that high affinity anti-influenza antibodies generally characterize the plasmablast responses of SLE patients with low levels of autoreactivity; however, certain exceptions were noted. The high-avidity antibody responses in SLE patients may also be correlated with cytokines that are abnormally expressed in lupus. These findings provide insights into the effects of dysregulated immunity on the quality of antibody responses following influenza vaccination and further our understanding of the underlying abnormalities of lupus.