Concomitant nivolumab-associated Grover disease and bullous pemphigoid in a patient with metastatic renal cell carcinoma.

Immune checkpoint inhibitor (ICI)-induced bullous pemphigoid (BP) and Grover disease (GD) are uncommon, and concomitant GD and BP is rarer still. We report a third case of concomitant BP and GD associated with nivolumab with emphasis on the clinical, histopathologic and immunofluorescence findings as well as differential diagnoses. A 73-year-old male with metastatic renal cell carcinoma on nivolumab developed erythematous scaly papules on the trunk with biopsy showing suprabasal acantholysis with dyskeratosis, consistent with GD. Subsequently, he developed widespread lesions on arms, legs, trunk, and scrotum with new vesiculobullae and urticarial lesions. Biopsy of a vesicle showed subepidermal blister with numerous eosinophils and neutrophils, and immunofluorescence and serological studies were supportive of BP. He continued to have clinically apparent GD that was confirmed on repeat biopsy. The patient was diagnosed with concomitant GD and BP induced by nivolumab and successfully treated with dupilumab. The relationship between ICI-induced GD and BP is not well understood; it has been suggested that T-cell activation against the BP180 antigen expressed on surface of tumor cells may predispose susceptible individuals to BP. Subsequent ICI-induced GD may create keratinocyte injury needed to expose additional proteins to reactivated and autoreactive T-cells, leading to autoimmunity. An important differential diagnosis is bullous GD, which can be distinguished by negative immunofluorescence and serological studies.

Prevalence of Myositis-Specific Autoantibodies and Myositis-Associated Autoantibodies in COVID-19 Patients: A Pilot Study and Literature Review.

Coronavirus disease 2019 (COVID-19) infection has been linked to numerous autoimmune manifestations. Neither the mechanism nor the etiology of this association has been fully explored or elucidated. Prior studies have detected myositis in patients with proven COVID-19 infection, suggesting a relationship between severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection and the development of myositis. Studies have reported elevated levels of autoimmune antibodies, including myositis-specific autoantibodies (MSAs) and myositis-associated autoantibodies (MAAs), in patients with COVID-19 infection, however the prevalence is not well documented. Our objective was to assess the prevalence of MSAs and MAAs in COVID-19 patients compared with unaffected subjects. Serum samples from 74 unvaccinated, polymerase chain reaction (PCR)-positive COVID-19 infected patients were compared with serum samples from 41 healthy, unaffected individuals. All serum samples were tested for MSA and MAA reactivity. Within the COVID-19-positive group, six (8.1%) patients exhibited MSA/MAA positivity, compared with only one (2.4%) individual from the control group. Although a higher prevalence of MSA/MAA positivity was observed within the COVID-19 infected group, the difference did not reach statistical significance (p=0.223). The autoantibodies detected in this study have a unique association with dermatomyositis and other inflammatory myopathies, and may play a role in COVID-19-associated myopathy. This article was previously presented as an abstract at Jacobs School of Medicine and Biomedical Sciences Research Day on June 3rd, 2022.

When Bullous Pemphigoid Is Not Bullous Pemphigoid: The Importance of Going Beyond Direct Immunofluorescence.

Bullous pemphigoid (BP) is the most common autoimmune bullous disease, but rarer forms of pemphigoid may appear identical to BP on routine histopathology and direct immunofluorescence (DIF). Here, we present the case of a 60-year-old man, who was initially thought to have BP, with supportive findings on routine histopathology and DIF. However, prominent oral involvement and cutaneous lesions refractory to conventional treatment suggested an alternate diagnosis. Further workup was performed, including indirect immunofluorescence (IIF) on salt-split skin, which showed binding of antibodies to the dermal floor rather than to the blister roof, and enzyme-linked immunosorbent assay for pemphigus and pemphigoid antibodies. With these additional tests, we concluded that the patient does not have BP but rather anti-p200 pemphigoid, anti-p105 pemphigoid, or a yet undiscovered form of pemphigoid. We reached a presumptive diagnosis of anti-p200 pemphigoid, as it is the most common pemphigoid with serum antibodies to the dermal floor of human salt-split skin by IIF. This case demonstrates that suspicion for other autoimmune bullous diseases in cases of treatment-refractory and clinically aberrant BP is essential. A limited workup may lead to a missed diagnosis and ultimately less efficient disease management.

Evaluation of a Newly Available ELISA for Envoplakin Autoantibodies for the Diagnosis of Paraneoplastic Pemphigus.

IMPORTANCE: Paraneoplastic pemphigus (PNP) is routinely diagnosed by the presence of autoantibodies for desmoplakin by indirect immunofluorescence (IIF) on rat bladder epithelium (RBE). IIF on RBE has recently been found to be positive in select cases of other blistering disorders. A new ELISA that detects envoplakin autoantibodies has recently been developed for the diagnosis of PNP. In this study, we measure the specificity of IIF on RBE and compare it to the new ELISA. OBSERVATIONS: We measured the specificity of IIF on RBE to be 86% which is on the lower end of the previously reported specificity of 83% to 98.9%. The ELISA for envoplakin autoantibodies has a technical sensitivity of 100%, diagnostic sensitivity of 83%, and specificity of 91%. CONCLUSIONS AND RELEVANCE: This ELISA for envoplakin autoantibodies is now commercially available and technically easier to perform then the immunoblot. We recommend that this new ELISA serves as a confirmatory test in cases of a positive IIF on RBE given its higher specificity.

Comparisons of pathologic and normal skin reactive autoantibodies and the interference phenomenon.

Immunofluorescent serum studies of the roles of the two groups of normal complement-fixing autoantibodies in psoriasis are complicated by the interference phenomenon. Both antibodies have the potential to react in vivo at sites of trauma and in psoriasiform lesions. In serum tests, only one or the other reacts, as demonstrated by immunofluorescent serum tests and absorption studies with isolated stratum corneum antigen. In tests of 15 normal sera, only one consistently reacted with the soluble carbohydrate antigens; the rest consistently reacted with the glycoproteins of the keratin intermediate filaments. This appears to be due to an antibody interference reaction that permits only one of two or more antibodies to react on a given tissue section.

Neonatal linear immunoglobulin a bullous dermatosis: a rare presentation.

Linear immunoglobulin A bullous dermatosis (LABD) is an autoimmune blistering disease that most commonly presents in preschool-aged children. There have been few neonatal reports, all of which had life-threatening aerodigestive complications requiring mechanical intervention and systemic therapy. We present a case of LABD in a neonate who had an uncomplicated course and was treated conservatively with only low-potency topical corticosteroids and wound care before resolution of his skin lesions.

Can direct immunofluorescence testing still be accurate if performed on biopsy specimens after brief inadvertent immersion in formalin?

BACKGROUND: Direct immunofluorescence is useful in the diagnosis of autoimmune, vesiculobullous, and connective tissue diseases. Michel medium is typically indicated for transport, but clinicians may inadvertently place samples into formalin. OBJECTIVE: We set out to determine the amount of time that specimens can remain in 10% buffered formalin and still retain their diagnostic properties. METHODS: Biopsy samples were examined from cases with established diagnoses of bullous pemphigoid (n = 12), dermatitis herpetiformis (n = 6), and pemphigus vulgaris (n = 6) and exposed to formalin for time points ranging from 2 minutes to 4 hours. RESULTS: We found that immunoreactants were detectable in the majority of samples when subjected to 2 minutes of formalin exposure. Dermatitis herpetiformis and pemphigoid samples retained immunogenicity for 10 minutes, whereas pemphigus showed reduced immunogenicity for all samples studied. A nonimmunologic nuclear fluorochroming pattern was noted in some of the specimens after formalin immersion. LIMITATIONS: Sample size, only examining 3 disease processes, and samples already having been in Michel medium were the major limitations in the study. CONCLUSION: In direct immunofluorescence studies, formalin exposure to biopsy specimens causes two types of artifactual changes: (1) the shortest exposure (2 minutes) causes complete loss of diagnostic markers of pemphigus; and (2) prolonged exposure changes tissue to a form that allows fluorescein-labeled antibodies to give fluorochroming reactions of nuclei (which can be mistaken for in vivo antinuclear antibody reactions of lupus erythematosus). After time intervals of 10 minutes to 2 hours, direct immunofluorescence studies of proven cases of bullous pemphigoid and dermatitis herpetiformis retained variable levels of specific reactivity.

A case of bullous disease limited to the skin illustrates the spectrum of neoplasia-induced autoimmunity.

Although the initial report of paraneoplastic pemphigus described individuals with mucocutaneous blistering disease, subsequent reports identified patients with lichen planus or graft versus host disease-like changes. We describe a patient with fatal autoimmune blistering disease with absence of mucous membrane lesions. The pattern of complement indirect immunofluoresence helped identify the prognosis prospectively. This case illustrates yet another presentation of the neoplasia-induced autoimmunity.

Measles outbreak in a Periurban area of Chandigarh: need for improving vaccine coverage and strengthening surveillance.

OBJECTIVE: An outbreak of measles was investigated in the periurban areas of Chandigarh Union Territory, during the months of December 1998 to February 1999. Mainly the children below 15 years of age were affected. The children of migrant labourers belonging to the neighbouring states of Uttar Pradesh and Bihar constituted the majority of population in the area under study. They belonged to lower socio economic status with low immunization coverage. METHODS: A total of 2968 houses were surveyed for epidemiological investigations in the areas of colony No. 5, Ramdarbar, Palsora and Pandit colony of Kajheri, covering a population of 14,601 and 7.3% (216/2968) of families were affected in the outbreak. RESULTS: Two hundred and eighty three cases of measles were reported with an attack rate of 4.5% and male to female ratio of (M:F) 5.3%:3.6%. Among the measles cases, 48.8% had received measles vaccination. The outbreak was investigated by detecting measles specific IgG/IgM antibodies either in acute or convalescent serum samples or both. Due to inadequate surveillance system and containment measures, the outbreak was in full swing during the winter months. Measles related complications were reported in 31.1% cases (i.e. diarrhoea in 15.2% and Pneumonia is 7.1%). CONCLUSION: Following smallpox and guinea worm eradication, WHO's next thrust, is on eradication of poliomyelitis and measles. Hence, strengthening of disease surveillance as well as vaccination policies are mandatory to achieve disease control in these areas.

Role of viral serology in the diagnosis of acute retinal necrosis syndrome.

Due to the devastating nature of acute retinal necrosis syndrome (ARNS), early diagnosis is essential. 5 cases of clinically diagnosed ARNA were investigated for CMC, herpes simplex and varicella zoster virus (VZV) infections. Of the three VZV IgM positive cases, two were positive in acute blood samples and one in vitreous fluid. Thus VZU can be incriminated as the causative agent of ARNS cases in North India.