B Cell Signatures Distinguish Cutaneous Lupus Erythematosus Subtypes and the Presence of Systemic Disease Activity

Cutaneous lupus erythematosus (CLE) is a chronic inflammatory skin disease characterized by a diverse cadre of clinical presentations. CLE commonly occurs in patients with systemic lupus erythematosus (SLE), and CLE can also develop in the absence of systemic disease. Although CLE is a complex and heterogeneous disease, several studies have identified common signaling pathways, including those of type I interferons (IFNs), that play a key role in driving cutaneous inflammation across all CLE subsets. However, discriminating factors that drive different phenotypes of skin lesions remain to be determined. Thus, we sought to understand the skin-associated cellular and transcriptional differences in CLE subsets and how the different types of cutaneous inflammation relate to the presence of systemic lupus disease. In this study, we utilized two distinct cohorts comprising a total of 150 CLE lesional biopsies to compare discoid lupus erythematosus (DLE), subacute cutaneous lupus erythematosus (SCLE), and acute cutaneous lupus erythematosus (ACLE) in patients with and without associated SLE. Using an unbiased approach, we demonstrated a CLE subtype-dependent gradient of B cell enrichment in the skin, with DLE lesions harboring a more dominant skin B cell transcriptional signature and enrichment of B cells on immunostaining compared to ACLE and SCLE. Additionally, we observed a significant increase in B cell signatures in the lesional skin from patients with isolated CLE compared with similar lesions from patients with systemic lupus. This trend was driven primarily by differences in the DLE subgroup. Our work thus shows that skin-associated B cell responses distinguish CLE subtypes in patients with and without associated SLE, suggesting that B cell function in skin may be an important link between cutaneous lupus and systemic disease activity.

Patient characteristics associated with response to NSAID monotherapy in children with systemic juvenile idiopathic arthritis

BACKGROUND

Systemic juvenile idiopathic arthritis (sJIA) is an auto-inflammatory disease characterized by fever, arthritis, and ≥1 of rash, generalized lymphadenopathy, hepato/splenomegaly, and serositis. Non-steroidal anti-inflammatory drugs (NSAIDs) are among the initial treatments of sJIA, but there is currently no evidence indicating which children should undergo a trial of NSAID monotherapy and which should not. Our objective is to identify presentation characteristics which are associated with response and lack of response to a trial of NSAID monotherapy.

METHODS

This is a retrospective single-center cohort study of children diagnosed with sJIA from 2000 to 2014. Patient demographics and disease characteristics were investigated to identify predictors of response to NSAID monotherapy.

RESULTS

Eighty-seven children were newly diagnosed with sJIA 2000-2014. Thirteen of the 51 children who received NSAID monotherapy achieved clinically inactive disease (CID) without other medications. Age at presentation (≤8 years old), initial joint count (≤5), and C-reactive protein (CRP) (≤13 mg/dL) at diagnosis were associated with achievement of CID on NSAIDs alone. Physicians were less likely to trial NSAID monotherapy if the patient had either serositis or macrophage activation syndrome (MAS) at diagnosis. Ultimate achievement of CID and time to CID were not significantly affected by whether the patient received a trial of NSAID monotherapy.

CONCLUSIONS

While a subset of children with sJIA can achieve CID with NSAID monotherapy, we recommend against a trial in patients who are >8 years old, with >5 joints involved, or with CRP > 13 mg/dL. Patients who undergo a trial of NSAID monotherapy should follow up within 2-4 weeks to evaluate for possible need for drug escalation. Clinical trials are necessary to confirm these findings.

Negative pressure wound therapy for managementof the surgical incision in orthopaedic surgery: A review of evidence and mechanisms for an emerging indication

Objectives

The period of post-operative treatment before surgical wounds are completely closed remains a key window, during which one can apply new technologies that can minimise complications. One such technology is the use of negative pressure wound therapy to manage and accelerate healing of the closed incisional wound (incisional NPWT).

Methods

We undertook a literature review of this emerging indication to identify evidence within orthopaedic surgery and other surgical disciplines. Literature that supports our current understanding of the mechanisms of action was also reviewed in detail.

Results

A total of 33 publications were identified, including nine clinical study reports from orthopaedic surgery; four from cardiothoracic surgery and 12 from studies in abdominal, plastic and vascular disciplines. Most papers (26 of 33) had been published within the past three years. Thus far two randomised controlled trials – one in orthopaedic and one in cardiothoracic surgery – show evidence of reduced incidence of wound healing complications after between three and five days of post-operative NPWT of two- and four-fold, respectively. Investigations show that reduction in haematoma and seroma, accelerated wound healing and increased clearance of oedema are significant mechanisms of action.

Conclusions

There is a rapidly emerging literature on the effect of NPWT on the closed incision. Initiated and confirmed first with a randomised controlled trial in orthopaedic trauma surgery, studies in abdominal, plastic and vascular surgery with high rates of complications have been reported recently. The evidence from single-use NPWT devices is accumulating. There are no large randomised studies yet in reconstructive joint replacement.

Cite this article: Bone Joint Res 2013;2:276–84.

Antioxidant defense of the midgut epithelium by the peritrophic envelope in caterpillars

The peritrophic envelope (PE) is an extracellular matrix that is secreted by the midgut epithelium in most arthropods. In addition to protecting the midgut epithelium from abrasive food particles and microbial pathogens, in vitro experiments have suggested that the PE functions as a radical-scavenging antioxidant in caterpillars. This study tested the hypothesis that the PE is a "sacrificial antioxidant" in vivo in caterpillars. As a sacrificial antioxidant, the PE would (1) bind catalytic metal ions, (2) become oxidized itself, and (3) protect the midgut epithelium from oxidative damage. Each of these functions was supported by our results: the PE in Malacosoma disstria adsorbed increased amounts of iron as the concentration of iron was increased in its diet. Iron adsorption by the PE helped protect the midgut epithelium of M. disstria from oxidative damage over a wide range of ingested iron concentrations. Secondly, while the midgut epithelium was protected, protein oxidation in the PE increased 108% when tannic acid was oxidized in the endoperitrophic space. Finally, when the formation of the PE was inhibited by Calcofluor, protein carbonyls in the midgut epithelia of M. disstria and Orgyia leucostigma increased by two- to threefold. We conclude that the PE functions as an effective iron-binding and radical-scavenging antioxidant that protects the midgut epithelia of caterpillars.

Distal femoral fracture fixation utilizing the Less Invasive Stabilization System (L.I.S.S.): the technique and early results

The treatment of supracondylar femoral fractures in the past three decades has evolved from non-operative to operative treatment. While operative fixation utilizing either plate fixation or rigid intramedullary nail fixation has improved patient outcomes, the problems of malunion, nonunion, need for bone grafting, joint stiffness, and infection persist. An emphasis on maintenance of the soft tissue envelope around fractures has improved efficacy in increasing osseous healing and decreasing infection. Out of this movement grew the concept of submuscular plating for distal femoral fractures, and subsequently L.I.S.S. fixation (Less Invasive Stabilization System) for distal femoral fractures. The technique and early results utilizing the L.I.S.S. for distal femoral fractures is described. The technique of L.I.S.S. fixation first begins with traditional direct visualization and internal fixation of the articular surface. Closed reduction is then performed on the metaphyseal / diaphyseal component of the fracture, followed by submuscular fixation utilizing the L.I.S.S. fixation. The L.I.S.S. can best be thought as an "internal" external fixator.

Isolation, via activity-directed fractionation, of mercaptobenzothiazole and dibenzothiazyl disulfide as 2 allergens responsible for tennis shoe dermatitis

Although contact dermatitis from shoes is common, the causative allergen is frequently not known. Reliance cannot be placed on standard screening trays because such testing can be negative when testing to shoe materials is positive. Furthermore, the relevance of positive screening tests is almost never proven by extracting that allergen from the patient's shoes. We present a case of insole dermatitis to tennis shoes in which we directly isolated the causative allergens by step-by-step patch-test monitoring of active fractions. Chromatographic separation of the active fractions led to the isolation of 2 allergens, mercaptobenzothiazole (Captax) (MBT) and its dimer, dibenzothiazyl disulfide (Altax) (DBTD). Patch tests to DBTD were noticeably more potent than those to MBT. In what might be considered an obvious case of contact sensitivity to MBT, the actual allergen is DBTD. Using this method, unknown shoe allergens can be isolated, identified, and added to the shoe test tray of potential allergens.