Lepromatous leprosy mimicking systemic lupus erythematosus: a clinical pathology conference held by the division of rheumatology at hospital for special surgery

CD4+ Cytotoxic T Cells Involved in the Development of EBV-Associated Diseases

Activated cytotoxic CD4 T cells (HLA-DR+) play an important role in the control of EBV infection, especially in cells with latency I (EBNA-1). One of the evasion mechanisms of these latency cells is generated by gp42, which, via peripherally binding to the β1 domain of the β chain of MHC class II (HLA-DQ, -DR, and -DP) of the infected B lymphocyte, can block/alter the HLA class II/T-cell receptor (TCR) interaction, and confer an increased level of susceptibility towards the development of EBV-associated autoimmune diseases or cancer in genetically predisposed individuals (HLA-DRB1* and DQB1* alleles). The main developments predisposing the factors of these diseases are: EBV infection; HLA class II risk alleles; sex; and tissue that is infiltrated with EBV-latent cells, forming ectopic lymphoid structures. Therefore, there is a need to identify treatments for eliminating cells with EBV latency, because the current treatments (e.g., antivirals and rituximab) are ineffective.

Lepromatous leprosy as a presenting feature of HIV

Various bacterial, mycobacterial and fungal opportunistic infections occur frequently in immunocompromised individuals, however, leprosy in retroviral disease is a relatively rare association. Hereby, we report a case of lepromatous leprosy that presented with clinical features mimicking other opportunistic infections and subsequently led to the diagnosis of HIV. The myriad challenges associated with the diagnosis and management of HIV-leprosy coinfection are also discussed. Thus, although uncommon, atypical cutaneous lesions in HIV-seropositive patients warrant investigation for leprosy.

Bacterial infections in lupus: Roles in promoting immune activation and in pathogenesis of the disease

BACKGROUND

Bacterial infections of the lung, skin, bloodstream and other tissues are common in patients with systemic lupus erythematosus (lupus) and are often more severe and invasive than similar infections in control populations. A variety of studies have explored the changes in bacterial abundance in lupus patients, the rates of infection and the influence of particular bacterial species on disease progression, using both human patient samples and mouse models of lupus.

OBJECTIVE

The aim of this review is to summarize human and mouse studies that describe changes in the bacterial microbiome in lupus, the role of a leaky gut in stimulating inflammation, identification of specific bacterial species associated with lupus, and the potential roles of certain common bacterial infections in promoting lupus progression.

METHODS

Information was collected using searches of the Pubmed database for articles relevant to bacterial infections in lupus and to microbiome changes associated with lupus.

RESULTS

The reviewed studies demonstrate significant changes in the bacterial microbiome of lupus patients as compared to control subjects and in lupus-prone mice compared to control mice. Furthermore, there is evidence supporting the existence of a leaky gut in lupus patients and in lupus-prone mice. This leaky gut may allow live bacteria or bacterial components to enter the circulation and cause inflammation. Invasive bacterial infections are more common and often more severe in lupus patients. These include infections caused by Staphylococcus aureus, Salmonella enterica, Escherichia coli, Streptococcus pneumoniae and mycobacteria. These bacterial infections can trigger increased immune activation and inflammation, potentially stimulating activation of autoreactive lymphocytes and leading to worsening of lupus symptoms.

CONCLUSIONS

Together, the evidence suggests that lupus predisposes to infection, while infection may trigger worsening lupus, leading to a feedback loop that may reinforce autoimmune symptoms.

Autoimmune manifestations of infections

PURPOSE OF REVIEW

To provide an update about the interactions between infections and autoimmune diseases (AIDs), from the molecular perspective to the clinical spectrum and the differentiation between infection and disease activity.

RECENT FINDINGS

Any kind of infection may modify the innate and adaptive immune response through the following mechanisms: molecular mimicry, superantigens, epitope spreading and B-cell activation. The consequence is the overproduction of antibodies shared with those found in AIDs. Viral infections, especially HIV and hepatitis C virus, can stimulate the production of antiphospholipid antibodies and confer an increased risk to develop antiphospholipid syndrome.

SUMMARY

The identification of risk factors to develop infections in patients with AIDs is remarkable to prevent them. These factors are the use of steroids and immunosuppressants, the involvement of a major organ (lungs, brain and kidney) and severe activity. Biomarkers to differentiate infection from disease activity are scarce, but the combination of procalcitonine and C-reactive protein seems to have higher specificity and sensibility to identify infections in patients with AIDs. Finally, the clinical judgment is the hallmark to differentiate between infections and disease activity.

Lepromatous leprosy mimicking systemic lupus erithematosus: a case report

The clinical manifestations of leprosy are highly variable, and the disease is notorious for being “a great imitator” of several other conditions. Leprosy may manifest with a variety of phenomena resembling those of autoimmune diseases. Herein, we report a 33-year-old male presenting with wounds on his left leg and hyperpigmented skin lesions all over his body. Six years earlier, the patient was diagnosed with systemic lupus erythematosus (SLE). However, therapy for SLE did not control his symptoms; instead, the patient developed features of leprosy, such as anesthetic skin lesions, nerve enlargement, and tenderness. Tests for antinuclear antibodies and anti-double stranded DNA antibodies were negative. Slit-skin smear showed a bacterial index of 6+ and morphological index of 10 %. Lupus band test results were negative. Histological findings were compatible with lepromatous leprosy. The clinical and serological similarities between leprosy and SLE may lead to erroneous diagnosis. Thus, clinicians should be aware of this characteristic for correct diagnosis.