Estimating the total treatment effect in randomized experiments with unknown network structure.

Randomized experiments are widely used to estimate the causal effects of a proposed treatment in many areas of science, from medicine and healthcare to the physical and biological sciences, from the social sciences to engineering, and from public policy to the technology industry. Here we consider situations where classical methods for estimating the total treatment effect on a target population are considerably biased due to confounding network effects, i.e., the fact that the treatment of an individual may impact its neighbors' outcomes, an issue referred to as network interference or as nonindividualized treatment response. A key challenge in these situations is that the network is often unknown and difficult or costly to measure. We assume a potential outcomes model with heterogeneous additive network effects, encompassing a broad class of network interference sources, including spillover, peer effects, and contagion. First, we characterize the limitations in estimating the total treatment effect without knowledge of the network that drives interference. By contrast, we subsequently develop a simple estimator and efficient randomized design that outputs an unbiased estimate with low variance in situations where one is given access to average historical baseline measurements prior to the experiment. Our solution does not require knowledge of the underlying network structure, and it comes with statistical guarantees for a broad class of models. Due to their ease of interpretation and implementation, and their theoretical guarantees, we believe our results will have significant impact on the design of randomized experiments.

Consensus-Based Recommendations on the Prevention of Squamous Cell Carcinoma in Solid Organ Transplant Recipients: A Delphi Consensus Statement.

IMPORTANCE: There is a paucity of evidence to guide physicians regarding prevention strategies for cutaneous squamous cell carcinoma (CSCC) in solid organ transplant recipients (SOTRs). OBJECTIVE: To examine the development and results of a Delphi process initiated to identify consensus-based medical management recommendations for prevention of CSCC in SOTRs. EVIDENCE REVIEW: Dermatologists with more than 5 years' experience treating SOTRs were invited to participate. A novel actinic damage and skin cancer index (AD-SCI), consisting of 6 ordinal stages corresponding to an increasing burden of actinic damage and CSCC, was used to guide survey design. Three sequential web-based surveys were administered from January 1, 2019, to December 31, 2020. Pursuant to Delphi principles, respondents thoroughly reviewed all peer responses between rounds. Supplemental questions were also asked to better understand panelists' rationale for their responses. FINDINGS: The Delphi panel comprised 48 dermatologists. Respondents represented 13 countries, with 27 (56%) from the US. Twenty-nine respondents (60%) were Mohs surgeons. Consensus was reached with 80% or higher concordance among respondents when presented with a statement, question, or management strategy pertaining to prevention of CSCC in SOTRs. A near-consensus category of 70% to less than 80% concordance was also defined. The AD-SCI stage-based recommendations were established if consensus or near-consensus was achieved. The panel was able to make recommendations for 5 of 6 AD-SCI stages. Key recommendations include the following: cryotherapy for scattered actinic keratosis (AK); field therapy for AK when grouped in 1 anatomical area, unless AKs are thick in which case field therapy and cryotherapy were recommended; combination lesion directed and field therapy with fluorouracil for field cancerized skin; and initiation of acitretin therapy and discussion of immunosuppression reduction or modification for patients who develop multiple skin cancers at a high rate (10 CSCCs per year) or develop high-risk CSCC (defined by a tumor with approximately ≥20% risk of nodal metastasis). No consensus recommendation was achieved for SOTRs with a first low risk CSCC. CONCLUSIONS AND RELEVANCE: Physicians may consider implementation of panel recommendations for prevention of CSCC in SOTRs while awaiting high-level-of-evidence data. Additional clinical trials are needed in areas where consensus was not reached.

Immune responses in COVID-19 respiratory tract and blood reveal mechanisms of disease severity

Although the respiratory tract is the primary site of SARS-CoV-2 infection and the ensuing immunopathology, respiratory immune responses are understudied and urgently needed to understand mechanisms underlying COVID-19 disease pathogenesis. We collected paired longitudinal blood and respiratory tract samples (endotracheal aspirate, sputum or pleural fluid) from hospitalized COVID-19 patients and non-COVID-19 controls. Cellular, humoral and cytokine responses were analysed and correlated with clinical data. SARS-CoV-2-specific IgM, IgG and IgA antibodies were detected using ELISA and multiplex assay in both the respiratory tract and blood of COVID-19 patients, although a higher receptor binding domain (RBD)-specific IgM and IgG seroconversion level was found in respiratory specimens. SARS-CoV-2 neutralization activity in respiratory samples was detected only when high levels of RBD-specific antibodies were present. Strikingly, cytokine/chemokine levels and profiles greatly differed between respiratory samples and plasma, indicating that inflammation needs to be assessed in respiratory specimens for the accurate assessment of SARS-CoV-2 immunopathology. Diverse immune cell subsets were detected in respiratory samples, albeit dominated by neutrophils. Importantly, we also showed that dexamethasone and/or remdesivir treatment did not affect humoral responses in blood of COVID-19 patients. Overall, our study unveils stark differences in innate and adaptive immune responses between respiratory samples and blood and provides important insights into effect of drug therapy on immune responses in COVID-19 patients.

Population-scale Longitudinal Mapping of COVID-19 Symptoms, Behavior, and Testing Identifies Contributors to Continued Disease Spread in the United States

Summary ParagraphDespite social distancing and shelter-in-place policies, COVID-19 continues to spread in the United States. A lack of timely information about factors influencing COVID-19 spread and testing has hampered agile responses to the pandemic. We developed How We Feel, an extensible web and mobile application that aggregates self-reported survey responses, to fill gaps in the collection of COVID-19-related data. How We Feel collects longitudinal and geographically localized information on users health, behavior, and demographics. Here we report results from over 500,000 users in the United States from April 2, 2020 to May 12, 2020. We show that self-reported surveys can be used to build predictive models of COVID-19 test results, which may aid in identification of likely COVID-19 positive individuals. We find evidence among our users for asymptomatic or presymptomatic presentation, as well as for household and community exposure, occupation, and demographics being strong risk factors for COVID-19. We further reveal factors for which users have been SARS-CoV-2 PCR tested, as well as the temporal dynamics of self-reported symptoms and self-isolation behavior in positive and negative users. These results highlight the utility of collecting a diverse set of symptomatic, demographic, and behavioral self-reported data to fight the COVID-19 pandemic.

Topical rapamycin reduces markers of senescence and aging in human skin: an exploratory, prospective, randomized trial.

Aging is a major risk factor for the majority of human diseases, and the development of interventions to reduce the intrinsic rate of aging is expected to reduce the risk for age-related diseases including cardiovascular disease, cancer, and dementia. In the skin, aging manifests itself in photodamage and dermal atrophy, with underlying tissue reduction and impaired barrier function. To determine whether rapamycin, an FDA-approved drug targeting the mechanistic target of rapamycin (mTOR) complex, can reduce senescence and markers of aging in human skin, an exploratory, placebo-controlled, interventional trial was conducted in a clinical dermatology setting. Participants were greater than 40 years of age with evidence of age-related photoaging and dermal volume loss and no major morbidities. Thirty-six participants were enrolled in the study, and nineteen discontinued or were lost to follow-up. A significant (P = 0.008) reduction in p16INK4A protein levels and an increase in collagen VII protein levels (P = 0.0077) were observed among participants at the end of the study. Clinical improvement in skin appearance was noted in multiple participants, and immunohistochemical analysis revealed improvement in histological appearance of skin tissue. Topical rapamycin reduced the expression of the p16INK4A protein consistent with a reduction in cellular senescence. This change was accompanied by relative improvement in clinical appearance of the skin and histological markers of aging and by an increase in collagen VII, which is critical to the integrity of the basement membrane. These results indicate that rapamycin treatment is a potential anti-aging therapy with efficacy in humans.Trial registration ClinicalTrials.gov Identifier: NCT03103893.

Prevalence and Types of Genital Lesions in Organ Transplant Recipients.

Importance: Squamous cell carcinoma (SCC) is the most common skin cancer diagnosed in solid organ transplant recipients (OTRs) and confers significant mortality. The development of SCC in the genital region is elevated in nonwhite OTRs. Viral induction, specifically human papillomavirus (HPV), is hypothesized to play a role in the pathophysiology of these lesions. Objective: To assess the prevalence and types of genital lesions observed in OTRs. Design, Setting, and Participants: This retrospective review included 496 OTRs who underwent full skin examination from November 1, 2011, to April 28, 2017, at an academic referral center. The review was divided into 2 distinct periods before a change in clinical management that took effect on February 1, 2016 (era 1) and after that change (era 2). Patient awareness of genital lesions was assessed. All lesions clinically suggestive of malignant tumors were biopsied and underwent HPV polymerase chain reaction typing. Main Outcomes and Measures: Number and types of genital lesions, proportion of malignant tumors positive for HPV, and patients cognizant of genital lesions. Results: Of the total 496 OTRs, 376 OTRs were evaluated during era 1 (mean [SD] age, 60 years; age range, 32-94 years; 45 [65.2%] male; 164 [43.6%] white) and 120 OTRs were evaluated during era 2 of the study (mean age, 56 years; age range, 22-79 years; 76 [63.3%] male; 30 [25.0%] white). Overall, 111 of the 120 OTRs (92.5%) denied the presence of genital lesions during the history-taking portion of the medical examination. Genital lesions were found in 53 OTRs (44.2%), cutaneous malignant tumors (basal cell carcinoma and SCC in situ) in 6 (5.0%), genital SCC in situ in 3 (4.2%), and condyloma in 29 (24.2%). Eight of the 12 SCC in situ lesions (66.7%) were positive for high-risk HPV. Seven tested positive for HPV-16 and HPV-18, and 1 tested positive for high-risk HPV DNA but could not be further specified. Conclusions and Relevance: Genital lesions in OTRs are common, but awareness is low. All OTRs should undergo thorough inspection of genital skin as a part of routine posttransplant skin examinations. Patients with darker skin types are disproportionately affected by cutaneous genital malignant tumors and should undergo a targeted program of early detection, prevention, and awareness focused on the risk of genital skin cancer after transplant. High-risk HPV subtypes are associated with genital SCC in OTRs. Additional studies are warranted to identify significant risk factors for HPV infection and to assess the utility of pretransplant HPV vaccination in the prevention of cutaneous genital malignant tumors.

Comparison of Posttransplant Dermatologic Diseases by Race.

Importance: The risk for skin cancer has been well characterized in white organ transplant recipients (OTRs); however, most patients on the waiting list for organ transplant in the United States are nonwhite. Little is known about cutaneous disease and skin cancer risk in this OTR population. Objective: To compare the incidence of cutaneous disease between white and nonwhite OTRs. Design, Setting, and Participants: This retrospective review of medical records included 412 OTRs treated from November 1, 2011, through April 22, 2016, at an academic referral center. Prevalence and characteristics of cutaneous disease were compared in 154 white and 258 nonwhite (ie, Asian, Hispanic, and black) OTRs. Clinical factors of cutaneous disease and other common diagnoses assessed in OTRs included demographic characteristics, frequency and type of cancer, anatomical location, time course, sun exposure, risk awareness, and preventive behavior. Main Outcomes and Measures: Primary diagnosis of malignant or premalignant, infectious, and inflammatory disease. Results: The 412 patients undergoing analysis included 264 men (64.1%) and 148 women (35.9%), with a mean age of 60.1 years (range, 32.1-94.3 years). White OTRs more commonly had malignant disease at their first visit (82 [67.8%]), whereas nonwhite OTRs presented more commonly with infectious (63 [37.5%]) and inflammatory (82 [48.8%]) conditions. Skin cancer was diagnosed in 64 (41.6%) white OTRs and 15 (5.8%) nonwhite OTRs. Most lesions in white (294 of 370 [79.5%]) and Asian (5 of 6 [83.3%]) OTRs occurred in sun-exposed areas. Among black OTRs, 6 of 9 lesions (66.7%) occurred in sun-protected areas, specifically the genitals. Fewer nonwhite than white OTRs reported having regular dermatologic examinations (5 [11.4%] vs 8 [36.4%]) and knowing the signs of skin cancer (11 [25.0%] vs 10 [45.4%]). Conclusions and Relevance: Early treatment of nonwhite OTRs should focus on inflammatory and infectious diseases. Sun protection should continue to be emphasized in white, Asian, and Hispanic OTRs. Black OTRs should be counseled to recognize the signs of genital human papillomavirus infection. Optimal posttransplant dermatologic care may be determined based on the race or ethnicity of the patients, but a baseline full-skin assessment should be performed in all patients. All nonwhite OTRs should be counseled more effectively on the signs of skin cancer, with focused discussion points contingent on skin type and race or ethnicity.

Nonmelanoma Skin Cancer in Nonwhite Organ Transplant Recipients.

Importance: Organ transplant recipients have a higher incidence of skin cancer. This risk is magnified over time and with continued exposure to immunosuppression. Skin cancer in nonwhite patients is associated with greater morbidity and mortality owing to diagnosis at a more advanced stage, which suggests that nonwhite organ transplant recipients are at even higher risk. Objective: To describe demographic and clinical factors and the incidence of skin cancer in nonwhite organ transplant recipients. Design, Setting, and Participants: We performed a retrospective medical record review of patients who were organ transplant recipients (154 were white and 259 nonwhite [black, Asian, Hispanic, Pacific Islander]) seen from November 1, 2011, to April 18, 2016 at an academic referral center. Main Outcomes and Measures: Variables were analyzed and compared between racial groups, including sex, age, race/ethnicity, Fitzpatrick type, type and location of skin cancer, type of organ transplanted, time to diagnosis of skin cancer after transplantation, and history of condyloma acuminata and/or verruca vulgaris. Results: Most of the 413 patients (62.7%) evaluated were nonwhite organ transplant recipients; 264 were men, and 149 were women. Their mean (SD) age was 60.09 (13.59) years. Nineteen skin cancers were identified in 15 patients (5.8%) representing 3 racial/ethnic groups: black (6 patients), Asian (5), and Hispanic (4). All squamous cell carcinomas in blacks were diagnosed in the in situ stage, located on sun-protected sites, and occurred in patients whose lesions tested positive for human papilloma virus (HPV) and/or who endorsed a history of condyloma acuminata or verruca vulgaris. Most skin cancers in Asians were located on sun-exposed areas and occurred in individuals who emigrated from equatorial locations. Conclusions and Relevance: Nonwhite organ transplant recipients are at risk for developing skin cancer posttransplantation. Follow-up in a specialized transplant dermatology center and baseline total-body skin examination should be part of posttransplantation care in all organ transplant recipients, including nonwhite patients. A thorough inspection of the groin and genitalia is imperative in black organ transplant recipients. History of HPV infection, particularly in black organ transplant recipients, and sun exposure/emigration history in Asian organ transplant recipients should be documented. Vigilant photoprotection may be of lesser importance in the prevention of skin cancer in black organ transplant recipients. Risk factors for nonwhite organ transplant recipients differ between races/ethnicities and warrant further study in efforts to better counsel and prevent skin cancer in these patients.

An unusual variant of confluent and reticulated papillomatosis masquerading as tinea versicolor.

BACKGROUND: Confluent and reticulated papillomatosis (CARP), also known as Gougerot-Carteaud syndrome, is a rare disorder. It usually presents as hyperkeratotic brown papules that coalesce into plaques with a reticulated periphery on the central trunk of young adults. Confluent and reticulated papillomatosis is most often clinically confused with tinea versicolor and usually does not respond to therapy with antifungals. Minocycline is the treatment of choice. OBSERVATIONS: Four cases of CARP with the unusual presentation of hypopigmented lesions masquerading as tinea versicolor in dark-skinned (Fitzpatrick skin types IV-V) patients are presented. All cases exhibited characteristic features of CARP on biopsy results and responded to minocycline of several months' duration. Two of the cases were also treated with adjuvant topical tazarotene. CONCLUSIONS: The hypopigmented variant of CARP in dark-skinned patients makes the clinical differentiation from tinea versicolor extremely challenging. Physicians encountering darkly pigmented individuals with hypopigmented plaques unresponsive to antifungals should have a high clinical suspicion for the hypopigmented variant of CARP.

Wells syndrome: an enigmatic and therapeutically challenging disease.

Wells syndrome, also known as eosinophilic cellulitis, is an uncommon condition whose etiology often remains a mystery. Patients present with recurrent cutaneous swellings that are often cellulitic in appearance. Histopathologic evaluation of the skin lesions reveals a dense dermal eosinophilic infiltrate, marked edema, and characteristic "flame figures". Notably, the picture is devoid of vasculitis. Therapy with low-dose systemic steroids has proven variably successful. Clinical evidence lending support for the efficacy of other medications has been, for the most part, anecdotal. We present a case of Wells syndrome, review the literature, and discuss therapeutic options.

Registration of MR and CT images of the liver: comparison of voxel similarity and surface based registration algorithms.

The purpose of this work was to determine the feasibility and efficacy of retrospective registration of MR and CT images of the liver. The open-source ITK Insight Software package developed by the National Library of Medicine (USA) contains a multi-resolution, voxel-similarity-based registration algorithm which we selected as our baseline registration method. For comparison we implemented a multi-scale surface fitting technique based on the head-and-hat algorithm. Registration accuracy was assessed using the mean displacement of automatically selected point landmarks. The ITK voxel-similarity-based registration algorithm performed better than the surface-based approach with mean misregistration in the range of 7.7-8.4 mm for CT-CT registration, 8.2 mm for MR-MR registration, and 14.0-18.9 mm for MR-CT registration compared to mean misregistration from the surface-based technique in the range of 9.6-11.1 mm for CT-CT registration, 9.2-12.4 mm for MR-MR registration, and 15.2-19.0 mm for MR-CT registration.