BACKGROUND: Prospective research is lacking on the utility of plucked hair outer root sheath direct immunofluorescence (ORS DIF) in the prediction of relapse in pemphigus vulgaris (PV) and the correlation of ORS DIF positivity with serum desmoglein antibody titers.
METHODS: We performed a prospective cohort study enrolling 80 PV patients in complete clinical remission at a tertiary care center in North India. Study participants underwent ORS DIF at baseline, which was repeated every 3 months. Skin biopsy DIF was done at study inclusion, repeated at 3 months, and upon clinical relapse. An antidesmoglein antibody titer was assessed concurrently with ORS DIF in a subset of patients. Patients on adjuvant therapy had their adjuvant therapy withdrawn either at the initial visit, at 3 months, or at a 6-month follow-up. Our objectives were to determine the association between positive ORS DIF and clinical relapse, the correlation between positive ORS DIF and skin biopsy DIF, and between positive ORS DIF and positive antidesmoglein antibody titers (when concurrently done).
RESULTS: Twenty-two patients (27.5%) had a clinical relapse. Baseline immunological markers significantly associated with relapse are ORS DIF positivity with IgG (16/36 [45.44%] P = 0.005) and C3 (12/29 [41.37%] P = 0.047) and greater intensity of baseline IgG and C3 positivity in ORS DIF (IgG, P = 0.002; C3, P = 0.033). Notably, a significant correlation was observed between baseline positive ORS DIF and skin biopsy DIF (IgG, ρ = 0.695; C3, ρ = 0.498). Positive ORS DIF strongly correlated with positive anti-Dsg3 antibody titers (φs = 0.815; P < 0.01). Early withdrawal of adjuvant immunosuppressant (within 3 months) (P = 0.007) and positive ORS DIF were also associated with relapse (P = 0.017).
CONCLUSIONS: ORS DIF is a reliable predictor of PV clinical relapse and demonstrated robust correlations with skin biopsy DIF and antidesmoglein antibody titers. Periodic assessment of ORS DIF aids in determining new-onset positivity that heralds clinical relapse.

Bipolar disorder (BP) is a recurring psychiatric condition characterized by alternating episodes of low energy (depressions) followed by manias (high energy). Cortical network activity produced by GABAergic interneurons may be critical in maintaining the balance in excitatory/inhibitory activity in the brain during development. Initially, GABAergic signaling is excitatory; with maturation, these cells undergo a functional switch that converts GABAA channels from depolarizing (excitatory) to hyperpolarizing (inhibitory), which is controlled by the intracellular concentration of two chloride transporters. The earliest, NKCC1, promotes chloride entry into the cell and depolarization, while the second (KCC2) stimulates movement of chloride from the neuron, hyperpolarizing it. Perturbations in the timing or expression of NKCC1/KCC2 may affect essential morphogenetic events including cell proliferation, migration, synaptogenesis and plasticity, and thereby the structure and function of the cortex. We derived induced pluripotent stem cells (iPSC) from BP patients and undiagnosed control (C) individuals, then modified a differentiation protocol to form GABAergic interneurons, harvesting cells at sequential stages of differentiation. qRT-PCR and RNA sequencing indicated that after six weeks of differentiation, controls transiently expressed high levels of NKCC1. Using multi-electrode array (MEA) analysis, we observed that BP neurons exhibit increased firing, network bursting and decreased synchrony compared to C. Understanding GABA signaling in differentiation may identify novel approaches and new targets for treatment of neuropsychiatric disorders such as BP.

OBJECTIVE: Pathogenic variants of the glycyl-tRNA synthetase 1 (GARS1) gene have been described as a cause of Charcot-Marie-Tooth disease type 2D, motor axonal neuropathy with upper limb predominance (distal hereditary motor neuropathy [dHMN] type V), and infantile spinal muscular atrophy.
METHODS: This cross-sectional, retrospective, observational study was carried out on 12 patients harboring the c.794C>T (p.Ser265Phe) missense pathogenic variant in GARS1. The patients\' clinical data, nerve conduction studies, magnetic resonance imaging (MRI), and intraepidermal nerve fiber density in skin biopsies were reviewed.
RESULTS: The mean age at onset was 9.5 years; the intrinsic hand muscles were affected before or at the same time as the distal leg musculature. The clinical examination revealed greater weakness of the distal muscles, with a more pronounced involvement of the thenar complex and the first dorsal interosseous in upper limbs. Electrophysiological studies were concordant with an exclusively motor axonal neuropathy. A pathologic split hand index was found in six patients. Muscle MRI showed predominant fatty infiltration and atrophy of the anterolateral and superficial posterior compartment of the legs. Most patients reported distal pinprick sensory loss. A reduced intraepidermal nerve fiber density was evident in skin biopsies from proximal and distal sites in nine patients.
CONCLUSIONS: GARS1 variants may produce a dHMN phenotype with \"split hand\" and sensory disturbances, even when sensory nerve conduction studies are normal. This could be explained by a dysfunction of sensory neurons in the dorsal ganglion that is reflected as a reduction of dermal nerve endings in skin biopsies without a distal gradient.

OBJECTIVE: Systemic Lupus Erythematosus (SLE) often causes damage to small nerve fibers, leading to distressing painful and autonomic symptoms. Despite this, Small Fiber Neuropathy (SFN) remains an underrecognized complication for SLE patients. In this cross-sectional study, we aimed to assess SFN in patients with SLE and to explore its correlations with immunologic disease features and clinical manifestations.
METHODS: We recruited 50 SLE patients (1 male to 12.5 females, aged 20-80 years) reporting painful disturbances. We conducted a comprehensive clinical and neurophysiological evaluation, using Nerve Conduction Studies and Quantitative Sensory Testing. Additionally, we carried out an extensive laboratory assessment of disease-related serological parameters. We also performed a thorough skin biopsy analysis, investigating somatic and autonomic innervation while detecting complement and inflammatory cell infiltrates within the skin.
RESULTS: Out of 50 patients, 19 were diagnosed with SFN, primarily characterized by a non-length-dependent distribution; 7 had a mixed neuropathy, with both large and small fiber involvement. Patients with SFN were younger than patients with a mixed neuropathy (p = .0143); furthermore, they were more likely to have a history of hypocomplementemia (p = .0058) and to be treated with cyclosporine A (p = .0053) compared to patients without neuropathy. However, there were no significant differences in painful and autonomic symptoms between patients with and without SFN.
CONCLUSIONS: This study highlights the relevant frequency of SFN with a non-length-dependent distribution among SLE patients experiencing painful symptoms. Indeed, SFN emerges as an early manifestation of SLE-related neuropathy and is closely associated with hypocomplementemia, suggesting a potential pathogenic role of the complement system. Moreover, SFN may be influenced by disease-modifying therapies. However, the precise role of SFN in shaping painful and autonomic symptoms in patients with SLE remains to be fully elucidated.

OBJECTIVE: To describe the frequency and clinicopathological concordance of mucocutaneous manifestations in people living with HIV (PLWH) and its correlation with CD4+ T lymphocyte count and HIV viral load.
METHODS: Cross-sectional study of patients diagnosed with HIV infection who underwent skin biopsy for histopathological study from 1992 to 2022. Skin diseases were categorized as opportunistic and sexually transmitted infections, inflammatory dermatoses, benign cutaneous neoplasms, and premalignant and malignant cutaneous neoplasms. Clinicopathological concordance was classified as complete, partial or discordant. Frequency of skin diseases are presented by category and according to lymphocyte CD4+ count and HIV viral load.
RESULTS: A total of 659 patients were included of whom 88.5% (n = 583) were male. The most frequent diagnostic category was opportunistic or sexually transmitted infections in 34% (n = 224) and the most frequently found condition was Kaposi sarcoma in 17% (n = 112). Clinicopathological concordance was complete in 53.7% (n = 354) of cases, partial in 26.7% (n = 176) and discordant in 19.6% (n = 129). Among the 282 patients with available serological data, 58.9% (n = 166), 23.8% (n = 67) and 17.4% (n = 49) had CD4+ counts below 200, between 200 and 499, and above 500 cells/μl, respectively.
CONCLUSIONS: Although there is a high variability in skin conditions which people with HIV may present, there was a high rate of clinicopathological concordance (80.4%). We emphasize the importance of diagnostic skin biopsies due to their diverse morphological presentation. The frequency of skin diseases in PLWH depending on different clinical settings should aid the clinician in reaching an adequate diagnosis in this population.

This manuscript reviews the significant skin manifestations of Lewy body disease, including Parkinson\'s disease and dementia with Lewy bodies, and the diagnostic utility of skin biopsy. Besides classic motor and cognitive symptoms, non-motor manifestations, particularly dermatologic disorders, can play a crucial role in disease presentation and diagnosis. This review explores the intricate relationship between the skin and Lewy body disease. Seborrheic dermatitis, autoimmune blistering diseases (bullous pemphigoid and pemphigus), rosacea, and melanoma are scrutinized for their unique associations with Parkinson\'s disease, revealing potential links through shared pathophysiological mechanisms. Advances in diagnostic techniques allow the identification of promising biomarkers such as α-synuclein in samples obtained by skin punch biopsy. Understanding the dermatologic aspects of Lewy body disease not only contributes to its holistic characterization but also holds implications for innovative diagnostic approaches.

The gold standard diagnosis of sporotrichosis is the isolation of Sporothrix sp. in culture media, but this is a time-consuming test that is susceptible to contamination and can be affected by the fungal load. Molecular methods such as nested PCR are gaining more ground in the management of several infections as they are tools for the rapid and accurate identification of microorganisms from pure cultures or directly from biological samples. This study aimed to apply a nested PCR molecular protocol for the rapid detection of Sporothrix spp. directly from clinical samples. Thirteen samples-six from skin biopsies, five from skin exudates, and two from conjunctival secretions-were obtained from patients diagnosed with sporotrichosis due to S. brasiliensis. Calmodulin gene sequencing identified all the isolates as S. brasiliensis. Nested PCR was able to detect all the Sporothrix sensu lato directly from clinical samples as well as the CBS 120339 reference strain. The nested PCR protocol stands out as a diagnostic alternative, as it allows the identification of Sporothrix spp. directly from clinical samples without the need for fungal isolation.

Background: The investigation of C-fiber-evoked ultralow-level responses (ULEPs) at somatic sites is difficult in clinical practice but may be useful in patients with small fiber neuropathy. Aim: The aim of the study was to investigate changes in LEPs and ULEPs in patients with fibromyalgia affected or not by abnormal intraepidermal innervation. Methods: We recorded LEPs and ULEPs of the hand, thigh and foot in 13 FM patients with a normal skin biopsy (NFM), 13 patients with a reduced intraepidermal nerve fiber density (IENFD) (AFM) and 13 age-matched controls. We used a YAP laser, changing the energy and spot size at the pain threshold for LEPs and at the heat threshold for ULEPs. Results: ULEPs occurred at a small number of sites in both the NFM and AFM groups compared to control subjects. The absence of ULEPs during foot stimulation was characteristic of AFM patients. The amplitude of LEPs and ULEPs was reduced in patients with AFM at the three stimulation sites, and a slight reduction was also observed in the NFM group. Conclusions: The present preliminary results confirmed the reliability of LEPs in detecting small fiber impairments. The complete absence of ULEPs in the upper and lower limbs, including the distal areas, could confirm the results of LEPs in patients with small fiber impairments. Further prospective studies in larger case series could confirm the present findings on the sensitivity of LEP amplitude and ULEP imaging in detecting small fiber impairments and the development of IENFD in FM patients.

UNASSIGNED: Cutaneous phosphorylated alpha-synuclein (p-α-syn) deposition is an important biomarker of idiopathic Parkinson\'s disease (iPD). Recent studies have reported synucleinopathies in patients with common genetic forms of PD.
UNASSIGNED: This study aimed to detect p-α-syn deposition characteristic in rare genetic PD patients with CHCHD2 or RAB39B mutations. Moreover, this study also aimed to describe peripheral alpha-synuclein prion-like activity in genetic PD patients, and acquire whether the cutaneous synucleinopathy characteristics of genetic PD are consistent with central neuropathologies.
UNASSIGNED: We performed four skin biopsy samples from the distal leg (DL) and proximal neck (C7) of 161 participants, including four patients with CHCHD2 mutations, two patients with RAB39B mutations, 16 patients with PRKN mutations, 14 patients with LRRK2 mutations, five patients with GBA mutations, 100 iPD patients, and 20 healthy controls. We detected cutaneous synucleinopathies using immunofluorescence staining and a seeding amplification assay (SAA). A systematic literature review was also conducted, involving 64 skin biopsies and 205 autopsies of genetic PD patients with synucleinopathy.
UNASSIGNED: P-α-syn was deposited in the peripheral cutaneous nerves of PD patients with CHCHD2, LRRK2, or GBA mutations but not in those with RAB39B or PRKN mutations. There were no significant differences in the location or rate of α-syn-positive deposits between genetic PD and iPD patients. Peripheral cutaneous synucleinopathy appears to well represent brain synucleinopathy of genetic PD, especially autosomal dominant PD (AD-PD). Cutaneous α-synuclein SAA analysis of iPD and LRRK2 and GBA mutation patients revealed prion-like activity.
UNASSIGNED: P-α-syn deposition in peripheral cutaneous nerves, detected using SAA and immunofluorescence staining, may serve as an accurate biomarker for genetic PD and iPD in the future.

UNASSIGNED: Tremor disorders have various genetic causes.
UNASSIGNED: A 60-year-old female with a family history of tremor presented a combined tremor syndrome, transient episodes of loss of contact and speech disturbances, as well as distal painful symptoms. Genetic screening revealed a novel heterozygous missense variant in the KCNQ2 gene.
UNASSIGNED: The KCNQ2 protein regulates action potential firing, and mutations in its gene are associated with epilepsy and neuropathic pain. The identified variant, although of uncertain significance, may disrupt KCNQ2 function and also play a role in tremor pathogenesis. This case highlights the importance of genetic screening in combined tremor disorders.