Reshaping the mosaic of autoimmunity

New-onset aplastic anemia after SARS-CoV-2 vaccination

Aplastic anemia (AA) is a rare autoimmune disease. Drugs, viruses, and radiation are among the most common etiologic factors, and most cases have immune pathophysiology. SARS-CoV-2 vaccines have been linked with rare side effects, including cases of acquired aplastic anemia. Here we review all the reported cases of new-onset AA after SARS-CoV-2 vaccination, and discuss their clinical characteristics and management. 18 patients in these case reports had a median age of 58 years. The time from vaccination to onset of aplastic anemia ranged from 1 day to 7 months, with a median of 2.5 weeks. Seventeen patients were diagnosed with severe or very severe aplastic anemia post-vaccination and all patients received standard treatments for acquired aplastic anemia. Seventeen patients achieved a complete or partial response and only 1 patient died. Aplastic anemia can be considered a very rare SARS-CoV-2 vaccine-related adverse event, although a causative relationship has not been proven. Reporting cases of such uncommon post-vaccination events could help clinicians to consider aplastic anemia when pancytopenia is observed after vaccination. The benefits of SARS-Cov-2 vaccination are established, and reports of rare events serve only to increase awareness in daily clinical practice.

Partners in crime: Autoantibodies complicit in COVID-19 pathogenesis

Autoantibodies (AABs) play a critical role in the pathogenesis of autoimmune diseases (AIDs) and serve as a diagnostic and prognostic tool in assessing these complex disorders. Viral infections have long been recognized as a principal environmental factor affecting the production of AABs and the development of autoimmunity. COVID-19 has primarily been considered a hyperinflammatory syndrome triggered by a cytokine storm. In the following, the role of maladaptive B cell response and AABs became more apparent in COVID-19 pathogenesis. The current review will primarily focus on the role of extrafollicular B cell response, Toll-like receptor-7 (TLR-7) activation, and neutrophil extracellular traps (NETs) formation in the development of AABs following SARS-CoV-2 infection. In the following, this review will clarify how these AABs dysregulate immune response to SARS-CoV-2 by disrupting cytokine function and triggering neutrophil hyper-reactivity. Finally, the pathologic effects of these AABs will be further described in COVID-19 associate clinical manifestations, including venous and arterial thrombosis, a multisystem inflammatory syndrome in children (MIS-C), acute respiratory distress syndrome (ARDS), and recently described post-acute sequelae of COVID-19 (PASC) or long-COVID.

Transient expression of antinuclear RNP-A antibodies in patients with acute COVID-19 infection

Introduction

Viral infections have been implicated in the initiation of the autoimmune diseases. Recent reports suggest that a proportion of patients with COVID-19 develop severe disease with multiple organ injuries. We evaluated the relationship between COVID-19 severity, prevalence and persistence of antinuclear and other systemic and organ specific autoantibodies as well as SARS-CoV2 infection specific anti-nucleocapsid (N) IgG antibodies and protective neutralizing antibody (Nab) levels.

Methods

Samples from 119 COVID-19 patients categorized based on their level of care and 284 healthy subjects were tested for the presence and persistence of antinuclear and other systemic and organ specific autoantibodies as well as SARS-CoV2 and neutralizing antibody levels.

Results

The data shows significantly increased levels of anti RNP-A, anti-nucleocapsid and neutralizing antibody among patients receiving ICU care compared to non-ICU care. Furthermore, subjects receiving ICU care demonstrated significantly higher nucleocapsid IgG levels among the RNP-A positive cohort compared to RNP-A negative cohort. Notably, the expression of anti RNP-A antibodies is transient that reverts to non-reactive status between 20 and 60 days post symptom onset.

Conclusions

COVID-19 patients in ICU care exhibit significantly higher levels of transient RNP-A autoantibodies, anti-nucleocapsid, and SARS-CoV2 neutralizing antibodies compared to patients in non-ICU care.

Primary Biliary Cholangitis with Ankylosing Spondylitis

Primary biliary cholangitis is a chronic inflammatory autoimmune liver disease that is characterized by a positive antimitochondrial antibodies test and progressive destruction of the small intrahepatic bile duct. Ankylosing spondylitis is a chronic, systemic, inflammatory disease of the spine and the sacroiliac joints. The association between these two is very low. This paper reports a rare case who had ankylosing spondylitis and developed primary biliary cholangitis.

Characteristics and Inpatient Outcomes of Primary Biliary Cholangitis and Autoimmune Hepatitis Overlap Syndrome

BACKGROUND AND AIMS

Primary biliary cholangitis (PBC) and autoimmune hepatitis (AIH) are hepatobiliary diseases of presumed immune-mediated origin that have been shown to overlap. The aim of this retrospective trial was to use national data to examine the characteristics and outcomes of patients hospitalized with overlapping PBC and AIH (PBC/AIH).

METHODS

The National Inpatient Sample was used to identify hospitalized adult patients with PBC, AIH, and PBC/AIH from 2010 to 2014 by International Classification of Diseases-Ninth Edition Revision codes; patients with hepatitis B virus and hepatitis C virus infection were excluded. Primary outcomes measures were in-hospital outcomes that included mortality, respiratory failure, septic shock, length of stay, and total hospital charges. Secondary outcomes were the clinical characteristics of PBC/AIH, including the comorbid extrahepatic autoimmune disease pattern and complications of cirrhosis.

RESULTS

A total of 3,478 patients with PBC/AIH were included in the study. PBC/AIH was associated with higher rates of Sjögren's syndrome (p<0.001; p<0.001), lower rates of Crohn's disease (p<0.05; p<0.05), and higher rates of cirrhosis-related complications when compared to PBC or AIH alone. There were similar rates of mortality between the PBC/AIH, PBC, and AIH groups. The PBC/AIH group had higher rates of septic shock when compared to the PBC group (p<0.05) and AIH group (p<0.05) after adjusting for possible confounders.

CONCLUSIONS

PBC/AIH is associated with a lower rate of Crohn's disease, a higher rate of Sjögren's syndrome, higher rates of cirrhosis-related complications, and significantly increased risk of septic shock compared to PBC and AIH individually.

Extrahepatic autoimmune diseases in primary biliary cholangitis: Prevalence and significance for clinical presentation and disease outcome

BACKGROUND AND AIM

The prevalence and clinical significance of extrahepatic autoimmune diseases (EHAIDs) have not been evaluated in a large cohort of primary biliary cholangitis (PBC).

METHODS

The medical records of 1554 patients with PBC from 20 international centers were retrospectively reviewed. Development of decompensated cirrhosis (ascites, variceal bleeding, and/or hepatic encephalopathy) and hepatocellular carcinoma were considered clinical endpoints.

RESULTS

A total of 35 different EHAIDs were diagnosed in 440 (28.3%) patients with PBC. Patients with EHAIDs were more often female (92.5% vs 86.1%, P < 0.001) and seropositive for anti-mitochondrial antibodies (88% vs 84%, P = 0.05) and antinuclear antibodies and/or smooth muscle antibodies (53.8% vs 43.6%, P = 0.005). At presentation, patients with EHAIDs had significantly lower levels of alkaline phosphatase (1.76 vs 1.98 × upper limit of normal [ULN], P = 0.006), aspartate aminotransferase (1.29 vs 1.50 × ULN, P < 0.001), and total bilirubin (0.53 vs 0.58 × ULN, P = 0.002). Patients with EHAIDs and without EHAIDs had similar rates of GLOBE high-risk status (12.3% vs 16.1%, P = 0.07) and Paris II response (71.4% vs 69.4%, P = 0.59). Overall, event-free survival was not different in patients with and without EHAIDs (90.8% vs 90.7%, P = 0.53, log rank). Coexistence of each autoimmune thyroid diseases (10.6%), Sjögren disease (8.3%), systemic sclerosis (2.9%), rheumatoid arthritis (2.7%), systemic lupus erythematosus (1.7%), celiac disease (1.7%), psoriasis (1.5%), and inflammatory bowel diseases (1.3%) did not influence the outcome.

CONCLUSIONS

Our study confirms that EHAIDs are frequently diagnosed in patients with PBC. The presence of EHAIDs may influence the clinical phenotype of PBC at presentation but has no impact on PBC outcome.

Zika autoimmunity and Guillain-Barré syndrome

PURPOSE OF REVIEW

To summarize the recent data regarding Guillain-Barré syndrome (GBS) as an autoimmune disorder following infection with Zika virus (ZIKV) infection, including the proposed pathogenic mechanisms and the role of autoantibodies.

RECENT FINDINGS

The loss of self-tolerance that leads to autoimmune diseases is a multifactorial process that may be illustrated as 'the mosaic of autoimmunity'. Infectious agents may contribute to the development of autoimmunity by several proposed mechanisms. One of the central mechanisms is molecular mimicry, which is also the most plausible mechanism in the case of ZIKV-induced autoimmune disorders.A recent meta-analysis found a low prevalence of GBS associated with ZIKV infection. Nevertheless, the estimated cost of illness for patients with GBS associated with ZIKV are tremendous and exceed 4.7 million dollars per year in Brazil alone.

SUMMARY

Currently, there is sufficient data to indicate that ZIKV infection is one of many triggers and factors that may contribute to the development GBS. Thus, it is advised to evaluate and determine ZIKV exposure and infection in the management of potential GBS patients.

Prolactin and autoimmunity: The hormone as an inflammatory cytokine

Nowadays, more than 80 autoimmune disorders are recognized, in which an aberrant immune response against different organs and tissues plays a crucial role. Hormonal homeostasis has great influence in achieving competent and healthy immune system function. Prolactin has a bioactive function acting as a hormone and a cytokine. It influences the immune system modulation, mainly inhibiting the negative selection of autoreactive B lymphocytes. Hyperprolactinemia has been detected in many patients with different autoimmune diseases, such as rheumatoid arthritis, systemic lupus erythematosus, Sjögren syndrome, multiple sclerosis, autoimmune thyroid disease, systemic sclerosis, among others, and its believed to play a crucial role in disease pathogenesis. A direct correlation between prolactin levels and disease activity was not clear. Genetic factors may have a role in humans as in animal models. Dopamine agonists have proven to offer clinical benefits among autoimmune patients and represent a promising therapy to be explored. In this review, the authors attempt to provide a critical overview on the role of prolactin in the immune system, exploring its contribution to the development of autoimmune diseases.

Elevated levels of antibodies against xenobiotics in a subgroup of healthy subjects

In spite of numerous research efforts, the exact etiology of autoimmune diseases remains largely unknown. Genetics and environmental factors, including xenobiotics, are believed to be involved in the induction of autoimmune disease. Some environmental chemicals, acting as haptens, can bind to a high-molecular-weight carrier protein such as human serum albumin (HSA), causing the immune system to misidentify self-tissue as an invader and launch an immune response against it, leading to autoimmunity. This study aimed to examine the percentage of blood samples from healthy donors in which chemical agents mounted immune challenges and produced antibodies against HSA-bound chemicals. The levels of specific antibodies against 12 different chemicals bound to HSA were measured by ELISA in serum from 400 blood donors. We found that 10% (IgG) and 17% (IgM) of tested individuals showed significant antibody elevation against aflatoxin-HSA adduct. The percentage of elevation against the other 11 chemicals ranged from 8% to 22% (IgG) and 13% to 18% (IgM). Performance of serial dilution and inhibition of the chemical–antibody reaction by specific antigens but not by non-specific antigens were indicative of the specificity of these antibodies. Although we lack information about chemical exposure in the tested individuals, detection of antibodies against various protein adducts may indicate chronic exposure to these chemical haptens in about 20% of the tested individuals. Currently the pathological significance of these antibodies in human blood is still unclear, and this protein adduct formation could be one of the mechanisms by which environmental chemicals induce autoimmune reactivity in a significant percentage of the population.

Sequential presentation of primary biliary cirrhosis and autoimmune hepatitis

BACKGROUND

Primary biliary cirrhosis (PBC)-autoimmune hepatitis (AIH) overlap syndrome is used to describe the coexistence of both diseases, with either a sequential or a simultaneous presentation in the same patient. Available studies have focused on the simultaneous form, whereas there is limited information on sequential PBC-AIH. We carried out a retrospective study of patients who sequentially developed PBC-AIH overlap syndrome.

METHODS

The medical data of 1065 patients diagnosed with PBC (n=483) and AIH (n=582) were retrospectively analyzed.

RESULTS

A sequential development of PBC-AIH was observed in 19 (1.8%) patients after a mean of 6.5 (1-14) years of follow-up. AIH developed in 12 (2.5%) PBC patients, whereas PBC occurred in seven (1.2%) patients with AIH. The baseline serologic and histological findings of patients who developed PBC-AIH were similar to those of patients with typical PBC or AIH. Eighteen patients were treated with a combination of ursodeoxycholic acid (UDCA) and immunosuppression after the diagnosis of PBC-AIH was established. One patient showed a spontaneous resolution of hepatitic flare under UDCA therapy. Biochemical remission was achieved in 16 patients, whereas three progressed to decompensated cirrhosis and required liver transplantation.

CONCLUSION

The sequential overlap of PBC-AIH can occur during the follow-up of patients with pure PBC or AIH. In our cohort, we could not identify any factors that predicted the development of this rare condition. The combination of UDCA and immunosuppression seems to be an appropriate therapy in the setting of PBC-AIH.

The mosaic of environment involvement in autoimmunity: the abrogation of viral latency by stress, a non-infectious environmental agent, is an intrinsic prerequisite prelude before viruses can rank as infectious environmental agents that trigger autoimmune diseases

An autoimmune disease (AD), organ-specific or systemic, results from an aberrant response in which the protective immune system normally schooled to recognize and destroy invading infectious agents (viruses, etc.) instead fails to distinguish self-antigens and proceeds to attack and destroy the host's organs. There can be familial aggregation in which a single AD may occur in members of a family, or a single family may be afflicted with multiple ADs. Finally, sometimes multiple ADs co-occur in a single individual: the kaleidoscope of autoimmunity. Autoimmunity is a multifactorial process in which genetic, hormonal, immunological and environmental factors act in concert to materialize the mosaic of autoimmunity phenomenon. A genetically primed individual may yet not develop an AD: the contribution by an environmental factor (non-infectious or infectious) is essential for completion of the act. Of the non-infectious factors, stress plays a determinative step in autoimmunity in that it abrogates viral latency and thereby ordains the viruses to qualify as infectious environmental factors that trigger ADs. This is note-worthy as viruses rank first as the most important environmental triggers of ADs. Furthermore, all these viruses experience going through latency. Hence the hypothesis: "The abrogation of viral latency by stress, a non-infectious environmental agent, is an intrinsic prerequisite prelude before viruses can rank as infectious environmental agents that trigger autoimmune diseases". There is collaboration here between non-infectious- and infectious-agent to achieve the cause of autoimmunity. We say viral latency and stress have a covenant: continued perpetration of autoimmunity is dependent on the intervention by stress to reactivate latent infections.

Novel pebbles in the mosaic of autoimmunity

Almost 25 years ago, the concept of the 'mosaic of autoimmunity' was introduced to the scientific community, and since then this concept has continuously evolved, with new pebbles being added regularly. We are now looking at an era in which the players of autoimmunity have changed names and roles. In this issue of BMC Medicine, several aspects of autoimmunity have been addressed, suggesting that we are now at the forefront of autoimmunity science. Within the environmental factors generating autoimmunity are now included unsuspected molecules such as vitamin D and aluminum. Some adjuvants such as aluminum are recognized as causal factors in the development of the autoimmune response. An entirely new syndrome, the autoimmune/inflammatory syndrome induced by adjuvants (ASIA), has been recently described. This is the new wind blowing within the branches of autoimmunity, adding knowledge to physicians for helping patients with autoimmune disease.

Autoimmune hepatitis/primary biliary cirrhosis overlap syndrome and associated extrahepatic autoimmune diseases

AIM

To assess the prevalence of concurrent extrahepatic autoimmune diseases in patients with autoimmune hepatitis (AIH)/primary biliary cirrhosis (PBC) overlap syndrome and applicability of the 'mosaic of autoimmunity' in these patients.

METHODS

The medical data of 71 AIH/PBC overlap patients were evaluated for associated autoimmune diseases.

RESULTS

In the study population, 31 (43.6%) patients had extrahepatic autoimmune diseases, including autoimmune thyroid diseases (13 patients, 18.3%), Sjögren syndrome (six patients, 8.4%), celiac disease (three patients, 4.2%), psoriasis (three patients, 4.2%), rheumatoid arthritis (three patients, 4.2%), vitiligo (two patients, 2.8%), and systemic lupus erythematosus (two patients, 2.8%). Autoimmune hemolytic anemia, antiphospholipid syndrome, multiple sclerosis, membranous glomerulonephritis, sarcoidosis, systemic sclerosis, and temporal arteritis were identified in one patient each (1.4%). A total of 181 autoimmune disease diagnoses were found in our patients. Among them, 40 patients (56.4%) had two, 23 (32.3%) had three, and eight (11.3%) had four diagnosed autoimmune diseases.

CONCLUSION

A large number of autoimmune diseases were associated with AIH/PBC overlap patients. Therefore, extended screening for existing autoimmune diseases during the routine assessment of these patients is recommended. Our study suggests that the concept of 'mosaic of autoimmunity' is a valid clinical entity that is applicable to patients with AIH/PBC overlap syndrome.

Evolving connective tissue disease influenced by splenectomy: beneath the sword of Dameshek

In years past, there was concern that splenectomy could lead to dissemination of occult systemic lupus erythematosus. Clinical studies subsequently effectively refuted that concept. However, there remains uncertainty regarding the role of the spleen in autoimmune diseases and the effect of splenectomy on their course. We present a case of a 56-year-old woman with autoimmune hepatitis and rheumatoid arthritis, without clinical or serologic features of lupus, who developed glomerulonephritis and antiphospholipid syndrome subsequent to an elective splenectomy. Literature review was performed to identify examples of the effect of splenectomy on other autoimmune diseases. Splenectomy has been linked with the development of new autoimmune phenomenon, alterations in the clinical course of patients with prior autoimmune disease, such as in our patient, and in a progressive redistribution of memory B cells that may influence autoimmune disease activity and may have been involved in the alteration in our patient's clinical course.

The role of infections in the immunopathogensis of systemic sclerosis--evidence from serological studies

Infections are believed to often play a role in the immunopathogenesis of autoimmune disorders; such is the case in systemic sclerosis (SSc). In order to evaluate the potential role infections may have on the pathogenesis of SSc, we assessed serological reactivity against various infectious agents in patients with SSc and compared them with healthy controls. Serological samples obtained from 80 patients with SSc were compared with 296 compatible healthy controls. Both groups were of European origin. All samples were tested for the presence of antibodies directed against hepatitis B virus, hepatitis C virus, toxoplasmosis, rubella, CMV, EBV, and Treponema pallidum. We applied Bio-Rad commercial and experimental kits to assess most antigens and ELISA assays to complete the panel. Patients with SSc had elevated IgM and IgG against Toxoplasma gondii and against CMV. Higher titers were also detected against the hepatitis B virus core protein (recombinant HBc antigen) using MONOLISA anti-HBc Plus commercial kit (Bio-Rad). A significantly higher rate of IgM antibodies against the capsid antigen of the EBV was detected in SSc patients compared with healthy controls, as well. These data demonstrate that antibodies against CMV, HBV, and toxoplasmosis were detected more often in patients with SSc. This association implies that infectious agents may have a role in disease pathogenesis and expression.

The effect of melanism and vitamin D synthesis on the incidence of autoimmune disease

Melanin has several physiological roles in maintaining health, but, notably, it affects the synthesis of vitamin D. Melanin is the primary determinant of the degree of skin pigmentation and protects the body from harmful ultraviolet radiation. Synthesis of 1,25-dihydroxyvitamin D(3) (1,25[OH](2)D(3)) in the skin, however, is dependent on ultraviolet B light. Highly pigmented skin, to the level found in people of African origin, abrogates almost all ultraviolet-induced 1,25(OH)(2)D(3) synthesis. Numerous animal models and clinical studies have underlined the essential role of vitamin D as a modulator of the different processes of the immune system. Evidence indicates that serum concentrations of 1,25(OH)(2)D(3) and the prevalence of autoimmune diseases in a certain population are associated with the latitude at which that population resides. This article explores the relationship between skin pigmentation, vitamin D and the prevalence of autoimmune disease.