[The regularity of sensory recovery after wound repair on the wrist and back of hand with anterolateral femoral flap without nerve anastomosis]

Objective: To investigate the regularity of sensory recovery after repairing the wounds on the wrist and back of hand with anterolateral femoral flap without nerve anastomosis. Methods: A cross-sectional study was conducted. From January 2018 to December 2020, patients who underwent free anterolateral femoral flaps without nerve anastomosis to repair wounds on the wrist and back of hand and met the inclusion criteria in Changshu Hai Yu Health Centre and Suzhou Ruihua Orthopedic Hospital were included in this study. Depending on the time interval between the day of the patient's surgery and the day of the cross-sectional survey, 80 patients were divided into 6-month group (15 males and 5 females, aged 22-63 years), 12-month group (16 males and 4 females, aged 21-65 years), 18-month group (15 males and 5 females, aged 25-61 years), and 24-month group (14 males and 6 females, aged 20-65 years), with 20 patients in each group. The area of skin and soft tissue defects after debridement ranged from 6.0 cm×4.5 cm to 18.0 cm×9.0 cm. Anterolateral femoral flaps were cut with areas of 7 cm×5 cm to 20 cm×10 cm and a thickness of 1.0 to 2.5 cm. Each transplanted flap was divided into A (proximal), B/D (bilateral), C (distal), and E (central) regions. The pain sensation, touch sensation, cold sensation, warmth sensation, and two-point discrimination (2-PD) in the aforementioned five regions and the differences in the five senses of the whole flap were tested and compared. Data were statistically analyzed with one-way analysis of variance, Fisher's exact probability test, chi-square test, or McNemar test. Results: In A region of anterolateral femoral flap without nerve anastomosis, compared with those in 6-month group, the pain sensation, touch sensation, cold sensation, and warmth sensation of flap of patients in 12-month group were significantly recovered (with χ2 values of 10.10, 14.55, 12.13, and 4.29, respectively, P<0.05 or P<0.01); compared with that in 12-month group, the warmth sensation of flap of patients in 18-month group recovered significantly (χ2=5.23, P<0.05). In B region, compared with those in 6-month group, the pain sensation, touch sensation, and cold sensation of flap of patients in 12-month group recovered significantly (with χ2 values of 5.58, 3.96, and 4.29, respectively, P<0.05); compared with those in 12-month group, the pain sensation, touch sensation, cold sensation, and warmth sensation of flap of patients in 18-month group recovered significantly (with χ2 values of 5.58, 3.96, 7.03, and 12.38, respectively, P<0.05 or P<0.01). In C region, compared with that in 6-month group, the pain sensation of flap of patients in 12-month group recovered significantly (χ2=4.80, P<0.05); Compared with that in 12-month group, the warmth sensation of flap of patients in 18-month group recovered significantly (χ2=10.16, P<0.01). In D region, compared with those in 6-month group, the pain sensation, touch sensation, and cold sensation of flap of patients in 12-month group recovered significantly (with χ2 values of 5.58, 4.29, and 3.96, respectively, P<0.05); compared with those in 12-month group, the pain sensation, touch sensation, cold sensation, and warmth sensation of flap of patients in 18-month group recovered significantly (with χ2 values of 5.58, 4.29, 3.96, and 10.10, respectively, P<0.05 or P<0.01). In E region, compared with that in 6-month group, the cold sensation of flap of patients in 12-month group recovered significantly (χ2=4.80, P<0.05); compared with those in 12-month group, the pain sensation, touch sensation, and warmth sensation of flap of patients in 18-month group recovered significantly (with χ2 values of 6.47, 4.91, and 9.23, respectively, P<0.05 or P<0.01). The five senses in the 5 regions of flap of patients in 24-month group were similar to those in 18-month group (P>0.05). The recovery of 2-PD in the 5 regions of flap of patients was similar between the two adjacent groups (P>0.05). In 12-month group, the recoveries of pain sensation, touch sensation, and cold sensation of flap of patients in A region were better than those in the other 4 regions (P<0.05 or P<0.01), the recovery of warmth sensation was better than that of B region, C region, and E region (P<0.05 or P<0.01); in 18-month group, the recovery of pain sensation, touch sensation, cold sensation, and warmth sensation of flap of patients in A region of was better than those in area C region (P<0.05). Compared with those in 6-month group, the pain sensation, touch sensation, and cold sensation of the whole flap of patients in 12-month group recovered significantly (with χ2 values of 7.62, 7.03, and 5.58, respectively, P<0.05 or P<0.01). Compared with the 12-month group in which 10, 11, 10, and 4 patients had a recovery of pain, touch sensation, cold sensation, and warmth sensation in the whole flap, the 18-month group had significantly more patients with sensations recovered, which were 17, 17, 16, and 14, respectively (with χ2 values of 5.58, 4.29, 3.96, and 10.10, respectively, P<0.05 or P<0.01). The five senses of the whole flap of patients in 24-month group were similar to those in 18-month group (P>0.05). Conclusions: In the anterolateral femoral flap without nerve anastomosis for repairing wounds on the wrist and back of hand, the sensation gradually recovered from the proximal end to the distal end. The sensation of touch, pain, and cold began to recover from 6 months after operation, and entered the stable recover period at 18 months after operation. Warmth sensation began to recover from 12 months after operation, and entered the stable recovery period at 18 months after operation. The 2-PD of most flaps was still not recovered 2-year after operation.

Differential effects of periodontal microbiome on the rheumatoid factor induction during rheumatoid arthritis pathogenesis

Association between exposure to periodontal bacteria and development of autoantibodies related to rheumatoid arthritis (RA) has been widely accepted; however, direct causal relationship between periodontal bacteria and rheumatoid factor (RF) is currently not fully understood. We investigated whether periodontal bacteria could affect RF status. Patients with preclinical, new-onset, or chronic RA underwent periodontal examination, and investigation of subgingival microbiome via 16S rRNA sequencing. Degree of arthritis and RF induction was examined in collagen-induced arthritis (CIA) mice that were orally inoculated with different periodontal bacteria species. Subsequently, single-cell RNA sequencing analysis of the mouse spleen cells was performed. Patients with preclinical RA showed an increased abundance of the Porphyromonadacae family in the subgingival microbiome compared to those with new-onset or chronic RA, despite comparable periodontitis severity among them. Notably, a distinct subgingival microbial community was found between patients with high-positive RF and those with negative or low-positive RF (p=0.022). Oral infections with the periodontal pathogens P. gingivalis and Treponema denticola in CIA mice similarly enhanced arthritis score, but resulted in different levels of RF induction. Genes related to B cell receptor signaling, B cell proliferation, activation, and differentiation, and CD4⁺ T cell costimulation and cytokine production were involved in the differential induction of RF in mice exposed to different bacteria. In summary, periodontal microbiome might shape RF status by affecting the humoral immune response during RA pathogenesis.

[Comparative study of the effects between second toe tibial dorsal artery flap and second toe tibial plantar proper artery flap in repairing finger skin and soft tissue defects]

Objective: To compare the effects between second toe tibial dorsal artery flap (2-TDAF) and second toe tibial plantar proper artery flap (2-TPPAF) in repairing finger skin and soft tissue defects. Methods: A retrospective cohort study was conducted. From January 2019 to June 2020, 27 patients with skin and soft tissue defects at the fingertips with area of 1.5 cm×1.2 cm-2.6 cm×1.8 cm after debridement who met the inclusion criteria were admitted to Suzhou Ruihua Orthopaedic Hospital, including 21 males and 6 females, aged 19-59 (37±10) years. According to flap repair methods used in the defective fingers, the patients were divided into 2-TDAF group (12 cases) and 2-TPPAF group (15 cases). The area of 2-TDAF ranged from 1.5 cm×1.2 cm to 2.5 cm×1.6 cm, and the area of 2-TPPAF ranged from 1.7 cm×1.3 cm to 2.6 cm×1.8 cm. Full-thickness skin grafts from the medial side of the ipsilateral leg were grafted to the wounds in donor sites, and the wounds in donor sites of skin grafts were directly sutured. Flap arterial diameter, flap excision time, flap survival situation of patients in 2 weeks after operation, and follow-up time were recorded. At the last follow-up, the two-point discrimination distance of flap graft site, total action motion (TAM) of the finger joints, and wound healing of the flap donor site were recorded; the Vancouver scar scale (VSS) was used to score the scar in donor area of the second toe and the recipient area of fingers; the appearance and self-satisfaction subscales of the Michigan hand outcomes questionnaire (MHQ) were used to evaluate the affected finger. Data were statistically analyzed with independent sample t test or Fisher's exact probability test. Results: The flap artery diameter of patients in 2-TDAF group was 0.35-0.80 (0.56±0.14) mm and the flap cutting time was (14.0±2.7) min, which were significantly shorter than 0.80-1.35 (1.02±0.16) mm and (19.7±3.4) min in 2-TPPAF group (with t values of 7.81 and 4.79, respectively, P<0.01). The flaps of patients in the 2 groups in recipient areas survived well in 2 weeks after operation, and the wounds in donor areas of flaps of patients in the 2 groups healed well at the last follow-up. There was no statistically significant difference in the postoperative follow-up time, and two-point discrimination distance of flap graft site, TAM of the finger joints, VSS score of scar in the second toe donor site and the finger recipient site, and the appearance and self-satisfaction of MHQ scores of the affected finger at the last follow-up (P>0.05). Conclusions: Compared with 2-TPPAF, 2-TDAF has a shallower anatomical layer and shorter time for surgical flap removal, which can preserve the proper arteries and nerves at the base of the toes and reduce the damage to the donor site.

[Clinical effects of proximal ulnar artery perforator flap combined with iliac bone graft in the reconstruction of subtotal thumb or finger defects]

Objective: To explore the clinical effects of proximal ulnar artery perforator flap combined with iliac bone graft in the reconstruction of subtotal thumb or finger defects. Methods: A retrospective observational study was conducted. From August 2016 to August 2019, 7 patients with thumb or finger defects caused by mechanical damage who met the inclusion criteria were admitted to Ruihua Affiliated Hospital of Soochow University, including 6 males and 1 female, aged 46 to 58 years. Their length of fingers was repaired with iliac bone, with length of 2.0 to 3.0 cm. After the bone graft, the skin defect area of the affected finger ranged from 2.8 cm×2.2 cm to 6.0 cm×3.2 cm. Then the free proximal ulnar artery perforator flap with area of 3.0 cm×2.4 cm to 6.5 cm×3.5 cm was used to cover the wounds. The wounds in donor sites of iliac crest and flap were directly sutured. The survival of flap in one week post surgery and the donor site wound healing in 2 weeks post surgery were observed, respectively. During the follow-up, the appearance and sensory function of the affected finger, bone healing, and scar hypertrophy of wound in the donor site were observed and evaluated. At the last follow-up, the functional recovery of the affected finger was evaluated with trial standard for the evaluation of functions of the upper limbs of the Hand Surgery Society of Chinese Medical Association. Results: In one week post surgery, all the flaps survived. In 2 weeks post surgery, the iliac bone and the wounds in forearm donor site healed. During the follow-up of 5 to 13 months, the flap was good in appearance, without obvious pigmentation; the sensory recovery reached level S2 in 5 patients and S0 in 2 patients; all the grafted iliac bones were bony union without obvious resorption; the wounds in donor site healed well, with only mild scar formation. At the last follow-up, the shape of the reconstructed finger was close to the healthy finger, and the functional evaluation results were excellent in 3 cases and good in 4 cases. Conclusions: The use of proximal ulnar artery perforator flap combined with iliac bone graft to reconstruct subtotal thumb or finger can partially restore part of the appearance and function, with less damage to the donor site. It is a good choice for patients who have low expectations of appearance and function for the reconstructed finger.

Isolated Tuberculous Myositis: A Systematic Review and Multicenter Cases

Objective

To investigate the clinical features and associated underlying conditions of isolated tuberculous myositis (ITBM), a rare extrapulmonary tuberculosis (TB).

Methods

A systematic literature search and a multicenter survey were performed using a triangulation strategy. Data from the identified ITBM cases were extracted and analyzed to determine the underlying conditions, clinical presentations, treatments, and outcomes.

Results

Based on the systematic review, we identified 58 ITBM, including 9 pediatric, cases in the literature published from 1981 to 2021 25 (43.1%) immunocompromised and 33 (56.9%) non-immunocompromised patients. Immunocompromised cases had a significant shorter symptom duration (median 30.0 vs. 75.0 days) and a higher prevalence of multilocular involvement (20.8% vs. 0%). Among 24 immunocompromised adult patients, dermatomyositis/polymyositis (DM/PM; n=10, 41.7%) were the most common underlying diseases in adults with ITBM identified in the systematic review. Over the past 20 years, 11 Korean adults with ITBM were identified in the multicenter survey. Of 7 immunocompromised cases, two (28.6%) were DM/PM patients. TB death rate of immunocompromised patients was 0.0% and 5/23 (21.7%) in the pediatric and adult ITBM cases identified in the systematic review, respectively, and 3/7 (42.9%) in survey-identified ITBM cases.

Conclusion

ITBM has a unique clinical presentation including fever, tenderness, local swelling, overlying erythema, abscess formation and was associated with a grave outcome, especially in immunocompromised hosts. DM/PM was a highly prevalent underlying disease in both systematic review-identified and survey-identified immunocompromised ITBM patients.

[Clinical effects of free superficial peroneal artery perforator flaps in repairing skin and soft tissue defects of the hallux]

Objective: To explore the clinical effects of free superficial peroneal artery perforator flaps in repairing skin and soft tissue defects of the hallux. Methods: A retrospective observational study was conducted. From January 2020 to January 2021, 13 patients with skin and soft tissue defects of the hallux who met the inclusion criteria were admitted to Department of Foot and Ankle Surgery of Ruihua Affiliated Hospital of Soochow University, including 12 males and 1 female, aged 26 to 53 years. Before operation, the perforating point of the superficial peroneal artery perforator was located by color Doppler ultrasound on the calf on the same side of the affected hallux and marked on the body surface. The operation was performed under spinal anesthesia combined with continuous epidural anesthesia. The area of skin and soft tissue defect after debridement was 4.5 cm×2.5 cm to 12.0 cm×3.0 cm. According to the size and shape of the wound, the superficial peroneal artery perforator flap was designed with the line between the fibular head and the lateral malleolus tip parallel shifting 2 cm to the tibial side as the flap axis line, and the perforating point of the perforator near the midpoint of the axis line as the center. The cut area of the flap was 5.0 cm×3.0 cm to 13.0 cm×4.0 cm, and part of the deep fascia was cut when the pedicle was freed. The donor site wound was sutured directly. During the operation, the number and type of the perforator and the cutting time of the flap were recorded, and the length of the perforator pedicle and diameter of the perforator were measured. The survival of the flap, the healing time and the healing condition of the donor and recipient areas were recorded after operation. The color, texture, elasticity of the flap, standing and walking functions of patients, the recovery of the donor area, and the patients' satisfaction with the recovery of the donor and recipient areas were recorded during the follow-up. At the last follow-up, the sensation of the flap was evaluated by the British Medical Association sensory function evaluation standard, the function of the affected limb was evaluated by the American Society of Foot and Ankle Surgery scoring system, and the excellent and good rate of the function of the affected limb was calculated. Results: A total of 13 perforators of the superficial peroneal artery were detected during the operation, all of which were septocutaneous perforators, and the perforator diameter was 0.3 to 0.5 mm. The vascular pedicle length was 2 to 5 cm. Flap cutting time was 11 to 26 minutes. The flaps of 13 patients all survived completely. The wounds at the donor and recipient sites healed well 9 to 18 days after operation. During follow-up of 6 to 14 months, the flaps had good color, texture, and elasticity; 11 patients had no obvious bloated appearance, and the other 2 patients underwent flap thinning and plastic surgery in the second stage because of their bloated appearance; all the patients returned to normal walking and standing functions. There was only one linear scar left in the donor site, with no obvious scar hyperplasia or hyperpigmentation. All the patients were satisfied with the recovery of the donor and recipient areas. At the last follow-up, the sensation of the flap was evaluated as grade S3 in 2 cases, grade S2 in 9 cases, and grade S1 in 2 cases; the function of the affected limb was evaluated as excellent in 7 cases and good in 6 cases, with an excellent and good rate of 100%. Conclusions: The free superficial peroneal artery perforator flap has relatively constant vascular anatomy, which is thin and wear-resistant, with less damage to the donor site after flap excision, and can preserve the shape and function of the hallux to the greatest extent. It is an effective method for repairing skin and soft tissue defect of the hallux.

Anti-fibrotic effect of a selective estrogen receptor modulator in systemic sclerosis

Background

The rarity of systemic sclerosis (SSc) has hampered the development of therapies for this intractable autoimmune disease. Induced pluripotent stem cell (iPSC) can be differentiated into the key disease-affected cells in vitro. The generation of patient-derived iPSCs has opened up possibilities for rare disease modeling. Since these cells can recapitulate the disease phenotypes of the cell in question, they are useful high-throughput platforms for screening for drugs that can reverse these abnormal phenotypes.

Methods

SSc iPSC was generated from PBMC by Sendai virus. Human iPSC lines from SSc patients were differentiated into dermal fibroblasts and keratinocytes. The iPSC-derived differentiated cells from the SSc patients were used on high-throughput platforms to screen for FDA-approved drugs that could be effective treatments for SSc.

Results

Skin organoids were generated from these cells exhibited fibrosis that resembled SSc skin. Screening of the 770-FDA-approved drug library showed that the anti-osteoporotic drug raloxifene reduced SSc iPSC-derived fibroblast proliferation and extracellular matrix production and skin fibrosis in organoids and bleomycin-induced SSc-model mice.

Conclusions

This study reveals that a disease model of systemic sclerosis generated using iPSCs-derived skin organoid is a novel tool for in vitro and in vivo dermatologic research. Since raloxifene and bazedoxifene are well-tolerated anti-osteoporotic drugs, our findings suggest that selective estrogen receptor modulator (SERM)-class drugs could treat SSc fibrosis.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13287-022-02987-w.

The Role of Transforming Growth Factor Beta in Joint Homeostasis and Cartilage Regeneration

Transforming growth factor-beta (TGF-β) is an important regulator of joint homeostasis, of which dysregulation is closely associated with the development of osteoarthritis (OA). In normal conditions, its biological functions in a joint environment are joint protective, but it can be dramatically altered in different contexts, making its therapeutic application a challenge. However, with the deeper insights into the TGF-β functions, it has been proven that TGF-β augments cartilage regeneration by chondrocytes, and differentiates both the precursor cells of chondrocytes and stem cells into cartilage-generating chondrocytes. Following documentation of the therapeutic efficacy of chondrocytes augmented by TGF-β in the last decade, there is an ongoing phase III clinical trial examining the therapeutic efficacy of a mixture of allogeneic chondrocytes and TGF-β-overexpressing cells. To prepare cartilage-restoring chondrocytes from induced pluripotent stem cells (iPSCs), the stem cells are differentiated mainly using TGF-β with some other growth factors. Of note, clinical trials evaluating the therapeutic efficacy of iPSCs for OA are scheduled this year. Mesenchymal stromal stem cells (MSCs) have inherent limitations in that they differentiate into the osteochondral pathway, resulting in the production of poor-quality cartilage. Despite the established essential role of TGF-β in chondrogenic differentiation of MSCs, whether the coordinated use of TGF-β in MSC-based therapy for degenerated cartilage is effective is unknown. We herein reviewed the general characteristics and mechanism of action of TGF-β in a joint environment. Furthermore, we discussed the core interaction of TGF-β with principal cells of OA cell-based therapies, the chondrocytes, MSCs, and iPSCs. Impact Statement Transforming growth factor-beta (TGF-β) has been widely used as a core regulator to improve or formulate therapeutic regenerative cells for degenerative joints. It differentiates stem cells into chondrocytes and improves the chondrogenic potential of differentiated chondrocytes. Herein, we discussed the overall characteristics of TGF-β and reviewed the comprehension and utilization of TGF-β in cell-based therapy for degenerative joint disease.

Mitigating Effect of Estrogen in Alzheimer’s Disease-Mimicking Cerebral Organoid

Alzheimer’s disease (AD) is the most common condition in patients with dementia and affects a large population worldwide. The incidence of AD is expected to increase in future owing to the rapid expansion of the aged population globally. Researchers have shown that women are twice more likely to be affected by AD than men. This phenomenon has been attributed to the postmenopausal state, during which the level of estrogen declines significantly. Estrogen is known to alleviate neurotoxicity in the brain and protect neurons. While the effects of estrogen have been investigated in AD models, to our knowledge, they have not been investigated in a stem cell-based three-dimensional in vitro system. Here, we designed a new model for AD using induced pluripotent stem cells (iPSCs) in a three-dimensional, in vitro culture system. We used 5xFAD mice to confirm the potential of estrogen in alleviating the effects of AD pathogenesis. Next, we confirmed a similar trend in an AD model developed using iPSC-derived cerebral organoids, in which the key characteristics of AD were recapitulated. The findings emphasized the potential of estrogen as a treatment agent for AD and also showed the suitability of AD-recapitulating cerebral organoids as a reliable platform for disease modeling and drug screening.

Chronic kidney disease in Korean patients with lupus nephritis: over a 35-year period at a single center

INTRODUCTION

Chronic kidney disease (CKD) is a major risk factor for overall morbidity and mortality even in lupus nephritis (LN) patients. However, less attention has been paid to the development of CKD in patients with LN. The objective of this study was to identify predictors for CKD with 35-year experience depending on newly revised guidelines for patients with LN.

METHODS

We conducted a retrospective cohort study for 401 patients who visited Seoul St. Mary's Hospital between January 1985 and December 2019. We analyzed clinical and laboratory indices, treatment response, the final renal function, and biopsy findings. The timing and cumulative risk of developing CKD were identified by Kaplan-Meier methods. Independent risk factors for developing CKD were examined by Cox proportional hazard regression analyses.

RESULTS

The median follow-up time after the diagnosis of LN was 131 months. CKD occurred in 15.5% of patients within 10 years after the diagnosis of LN. The development of CKD was associated with delayed-onset LN, acute renal dysfunction at onset of LN, and failure to reach complete response (CR) at 6 or 12 months rather than histopathological findings or the severity of proteinuria at onset of LN. Cumulative incidence of progression to CKD was significantly higher in patients with the three predictors mentioned above.

CONCLUSION

Ten-year cumulative incidence of CKD was about 15%. Our results showed that delayed-onset LN, acute renal dysfunction at the onset of LN, and inadequate treatment response assessed at 6 or 12 months after treatment were predictors for the development of CKD in LN. Key Points • CKD is a major risk factor for overall morbidity and mortality in LN patients. • Ten-year cumulative incidence of CKD was about 15% • Delayed-onset LN, acute renal dysfunction at the onset of LN, and inadequate treatment response assessed at 6 or 12 months after treatment were predictors for the development of CKD in LN.

Lupus Heart Disease Modeling with Combination of Induced Pluripotent Stem Cell-Derived Cardiomyocytes and Lupus Patient Serum

Background and Objectives

Systemic lupus erythematosus (SLE) is a chronic autoimmune disease mainly affecting young women of childbearing age. SLE affects the skin, joints, muscles, kidneys, lungs, and heart. Cardiovascular complications are common causes of death in patients with SLE. However, the complexity of the cardiovascular system and the rarity of SLE make it difficult to investigate these morbidities. Patient-derived induced pluripotent stem cells (iPSCs) serve as a novel tool for drug screening and pathophysiological studies in the absence of patient samples.

Methods and Results

We differentiated CMs from HC- and SLE-iPSCs using 2D culture platforms. SLE-CMs showed decreased proliferation and increased levels of fibrosis and hypertrophy marker expression; however, HC-and SLE-monolayer CMs reacted differently to SLE serum treatment. HC-iPSCs were also differentiated into CMs using 3D spheroid culture and anti-Ro autoantibody was treated along with SLE serum. 3D-HC-CMs generated more mature CMs compared to the CMs generated using 2D culture. The treatment of anti-Ro autoantibody rapidly increased the gene expression of fibrosis, hypertrophy, and apoptosis markers, and altered the calcium signaling in the CMs.

Conclusions

iPSC derived cardiomyocytes with patient-derived serum, and anti-Ro antibody treatment could serve in effective autoimmune disease modeling including SLE. We believe that the present study might briefly provide possibilities on the application of a combination of patient-derived materials and iPSCs in disease modeling of autoimmune diseases.

A clinical comparison of an endothelin receptor antagonist and phosphodiesterase type 5 inhibitors for treating digital ulcers of systemic sclerosis

OBJECTIVES

To assess the efficacy of an endothelin receptor antagonist (ERA) and phosphodiesterase type5 inhibitors (PDE5is) for treating SSc-related digital ulcers (DUs).

METHODS

This prospective, multicentre, observational cohort study recruited patients with active SSc-related DUs from 13 medical centres in South Korea. The primary outcome was time to cardinal ulcer (CU) healing. A secondary outcome was time to new DU occurrence. Patients were followed up 4, 8, 12 and 24 weeks after treatment initiation.

RESULTS

Sixty-three patients were analysed. Their mean age was 49.9 years (s.d. 11.4) and 49 were female. Twenty-eight had limited SSc. Forty-nine patients received ERA, 11 received a PDE5i (9 sildenafil, 1 udenafil and 1 tadalafil) and 3 received other medication. The hazard ratio (HR) for time to CU healing in the ERA group vs the PDE5i group was 0.75 (95% CI 0.35, 1.64; P = 0.47) in an unadjusted model and 0.80 (95% CI 0.36, 1.78; P = 0.59) in a model adjusted for age, sex, use of calcium channel blockers (CCBs), total DU number and initial CU area. The HR for new DU development in the ERA group vs the PDE5i group was 0.39 (95% CI 0.16, 0.93; P = 0.03) in an unadjusted model and 0.32 (95% CI 0.13, 0.81; P = 0.02) in an adjusted model. No patients receiving CCBs developed new DUs at 24 weeks.

CONCLUSION

Time to CU healing is comparable for ERA and PDE5i. ERAs are more effective in reducing new DU occurrence than PDE5is. CCBs may be effective as a background medication.

Renal function deterioration is an independent mortality determinant in Koreans diagnosed with lupus nephritis

OBJECTIVE

To evaluate the predictors of mortality, mortality rate, and causes of death in patients with lupus nephritis (LN) depending on final renal function.

METHODS

The cohort included 401 Korean patients diagnosed with LN between 1985 and 2019. We retrospectively analyzed the clinical and laboratory indices, treatment response, and the final renal function. The final renal function was defined by the last stable level of eGFR measured in an out-patient department more than 3 times before death occurred and was categorized into five groups depending on CKD stage.

RESULTS

The median follow-up time after the diagnosis of LN was 131 months. No difference in baseline demographic characteristics and laboratory findings was found except for the proportion of Hb less than 10 mg/dl and baseline eGFR (p = 0.011 and 0.037). We found no significant differences in therapeutic parameters, but all the response parameters including treatment response at 6 months (p = 0.004) and 12 months (p = 0.004), time to remission (p < 0.001), final renal response (p < 0.001), and the final renal function (p < 0.001) differed significantly between the two groups. In multivariate Cox proportional hazards analysis, the final renal function was an independent risk factor predicting mortality. The main causes of death were infection and SLE flare. Contrary to existing knowledge, SLE flare also triggered mortality in a few patients with LN progressed to end-stage renal disease (ESRD). Only two cases of mortality occurred in the kidney transplantation (KT) group (n = 25) with a median follow-up period of 224 months. The overall mortality rates calculated using the Kaplan-Meier method were 6.8%, 10.3%, 19.7%, and 28.0% at 5, 10, 20, and 30 years, respectively.

CONCLUSION

Renal function deterioration was an independent determinant of mortality in Korean patients with LN. SLE flare also caused mortality in patients with LN who required maintenance dialysis, suggesting the benefit of KT on lupus activity and survival.

Application of Induced Pluripotent Stem Cells for Disease Modeling and 3D Model Construction: Focus on Osteoarthritis

Since their discovery in 2006, induced pluripotent stem cells (iPSCs) have shown promising potential, specifically because of their accessibility and plasticity. Hence, the clinical applicability of iPSCs was investigated in various fields of research. However, only a few iPSC studies pertaining to osteoarthritis (OA) have been performed so far, despite the high prevalence rate of degenerative joint disease. In this review, we discuss some of the most recent applications of iPSCs in disease modeling and the construction of 3D models in various fields, specifically focusing on osteoarthritis and OA-related conditions. Notably, we comprehensively reviewed the successful results of iPSC-derived disease models in recapitulating OA phenotypes for both OA and early-onset OA to encompass their broad etiology. Moreover, the latest publications with protocols that have used iPSCs to construct 3D models in recapitulating various conditions, particularly the OA environment, were further discussed. With the overall optimistic results seen in both fields, iPSCs are expected to be more widely used for OA disease modeling and 3D model construction, which could further expand OA drug screening, risk assessment, and therapeutic capabilities.

Human kidney organoids model the tacrolimus nephrotoxicity and elucidate the role of autophagy

BACKGROUND/AIMS

Tacrolimus has been used as an immunosuppressive agent in organ transplantation. Despite the therapeutic benefits, tacrolimus's use is limited due to its nephrotoxicity. To reduce tacrolimus nephrotoxicity, effective humanized experimental models may be helpful. Here, we modeled tacrolimus nephrotoxicity using kidney organoids derived from human inducible pluripotent stem cells (iPSCs) in vitro.

METHODS

Kidney organoids were differentiated from the CMC11 iPSC cell line, re-seeded in 96-well plates, and treated with tacrolimus at doses of 0, 30, or 60 μM for 24 hours. This in vitro model was compared to a mouse model of tacrolimus nephrotoxicity and the associated mechanisms were investigated.

RESULTS

The size of the kidney organoids and cell viability decreased in dose-dependent manners after treatment with tacrolimus. The number of tubular cells decreased with a loss of polarity, similar to the effects seen in mouse tacrolimus nephrotoxicity. Ultrastructural analysis showed numerous vacuoles in the proximal tubular cells of the kidney organoids treated with tacrolimus. Tacrolimus treatment induced oxidative stress and mitochondrial dysfunction, and autophagic activity was enhanced in the kidney organoids. Rapamycin, an autophagy inducer, accelerated cell death in the kidney organoid model of tacrolimus nephrotoxicity, which was attenuated by treatment with 3-methyladenine, an autophagy inhibitor. These findings indicate that the augmentation of autophagy by rapamycin treatment accelerated tacrolimus nephrotoxicity.

CONCLUSION

Our data suggest that human kidney organoids are an effective in vitro model of tacrolimus nephrotoxicity and that autophagy plays a critical role in tacrolimus nephrotoxicity.

Review of the Current Trends in Clinical Trials Involving Induced Pluripotent Stem Cells

In 2006, the induced pluripotent stem cell (iPSC) was presented to the world, paving the way for the development of a magnitude of novel therapeutic alternatives, addressing a diverse range of diseases. However, despite the immense cell therapy potential, relatively few clinical trials evaluating iPSC-technology have actually translated into interventional, clinically applied treatment regimens. Herein, our aim was to determine trends in globally conducted clinical trials involving iPSCs. Data were derived both from well-known registries recording clinical trials from across the globe, and databases from individual countries. Comparisons were firstly drawn between observational and interventional studies before the latter was further analyzed in terms of therapeutic and nontherapeutic trials. Our main observations included global distribution, purpose, target size, and types of disorder relevant to evaluated trials. In terms of nontherapeutic trials, the USA conducted the majority, a large average number of participants-187-was included in the trials, and studies on circulatory system disorders comprised a slightly higher proportion of total studies. Conversely, Japan was the frontrunner in terms of conducting therapeutic trials, and the average number of participants was much lower, at roughly 29. Disorders of the circulatory, as well as nervous and visual systems, were all studied in equal measure. This review highlights the impact that iPSC-based cell therapies can have, should development thereof gain more traction. We lastly considered a few companies that are actively utilizing iPSCs in the development of therapies for various diseases, for whom the global trends in clinical trials could become increasingly important.

Promoting Long-Term Cultivation of Motor Neurons for 3D Neuromuscular Junction Formation of 3D In Vitro Using Central-Nervous-Tissue-Derived Bioink

3D cell printing technology is in the spotlight for producing 3D tissue or organ constructs useful for various medical applications. In printing of neuromuscular tissue, a bioink satisfying all the requirements is a challenging issue. Gel integrity and motor neuron activity are two major characters because a harmonious combination of extracellular materials essential to motor neuron activity consists of disadvantages in mechanical properties. Here, a method for fabrication of 3D neuromuscular tissue is presented using a porcine central nervous system tissue decellularized extracellular matrix (CNSdECM) bioink. CNSdECM retains CNS tissue-specific extracellular molecules, provides rheological properties crucial for extrusion-based 3D cell printing, and reveals positive effects on the growth and maturity of axons of motor neurons compared with Matrigel. It also allows long-term cultivation of human-induced-pluripotent-stem-cell-derived lower motor neurons and sufficiently supports their cellular behavior to carry motor signals to muscle fibers. CNSdECM bioink holds great promise for producing a tissue-engineered motor system using 3D cell printing.

Re-evaluation of the prognostic significance of oropharyngeal dysphagia in idiopathic inflammatory myopathies

OBJECTIVE

To investigate the prognostic significance of videofluorographic swallowing study (VFSS)-confirmed oropharyngeal dysphagia in idiopathic inflammatory myopathies (IIMs).

METHOD

We reviewed the medical records of patients who were diagnosed with IIM between 2009 and 2020 at Seoul St Mary's Hospital. All oropharyngeal dysphagia cases were limited to VFSS-confirmed dysphagia found during the initial diagnostic work-up for IIM. We described the findings on VFSS and the course of the dysphagic symptoms. Logistic regression and survival analyses were performed to evaluate the risk of pneumonia and mortality, respectively.

RESULTS

We found 88 patients with IIM who met the criteria. Among them, 17 patients (19%) had oropharyngeal dysphagia. Except for two cases lost to follow-up and one deceased case, all of the patients with dysphagia (14 of 14) had swallowing function restored within 6 months. The risk of pneumonia within 3 months from the diagnosis of IIM was significant [odds ratio = 4.49, 95% confidence interval (CI) 1.07-18.88]. The median follow-up duration was 34 and 27 months for the groups without and with dysphagia, respectively. The survival analysis failed to demonstrate that the presence of oropharyngeal dysphagia increased the risk of death (hazard ratio = 0.77, 95% CI: 0.085-7.00).

CONCLUSIONS

Oropharyngeal dysphagia found at the initial diagnosis of IIM improved within 3-6 months in nearly all cases. Furthermore, IIM patients who had oropharyngeal dysphagia at the initial diagnosis of IIM were not likely to have shorter survival, even if the risk of pneumonia was increased in the short term.

Perichondrium-inspired permeable nanofibrous tube well promoting differentiation of hiPSC-derived pellet toward hyaline-like cartilage pellet

The pellet formation has been regarded as a golden standard forin vitrochondrogenic differentiation. However, a spatially inhomogeneous chondrogenic microenvironment around a pellet resulted from the use of a traditional impermeable narrow tube, such as the conical tube, undermines the differentiation performance and therapeutic potential of differentiated cartilage pellet in defective articular cartilage treatment. To address this drawback, a perichondrium-inspired permeable nanofibrous tube (PINaT) well with a nanofibrous wall permeable to gas and soluble molecules is proposed. The PINaT well was fabricated with a micro deep drawing process where a flat thin nanofibrous membrane was transformed to a 3.5 mm deep tube well with a ∼50µm thick nanofibrous wall. Similar toin vivoperichondrium, the PINaT well was found to allow oxygen and growth factor diffusion required for chondrogenic differentiation across the entire nanofibrous wall. Analyses of gene expressions (COL2A1, COL10A1, ACAN, and SOX9), proteins (type II and X collagen), and glycosaminoglycans contents were conducted to assess the differentiation performance and clinical efficacy of differentiated cartilage pellet. The regulated spatially homogeneous chondrogenic microenvironment around the human induced pluripotent stem cell-derived pellet (3 × 10⁵cells per pellet) in the PINaT well remarkably improved the quality of the differentiated pellet toward a more hyaline-like cartilage pellet. Furthermore, an accelerated chondrogenic differentiation process of the pellet produced by the PINaT well was achieved for 14 days, demonstrating a hyaline cartilage-specific marker similar to the control pellet differentiated for 20 days. Finally, the enhanced clinical efficacy of the hyaline-like cartilage pellet was confirmed using an osteochondral defect rat model, with the repaired tissue resembling hyaline cartilage rather than fibrous cartilage after 8 weeks of regeneration.

Restoration of Osteogenesis by CRISPR/Cas9 Genome Editing of the Mutated COL1A1 Gene in Osteogenesis Imperfecta

Osteogenesis imperfecta (OI) is a genetic disease characterized by bone fragility and repeated fractures. The bone fragility associated with OI is caused by a defect in collagen formation due to mutation of COL1A1 or COL1A2. Current strategies for treating OI are not curative. In this study, we generated induced pluripotent stem cells (iPSCs) from OI patient-derived blood cells harboring a mutation in the COL1A1 gene. Osteoblast (OB) differentiated from OI-iPSCs showed abnormally decreased levels of type I collagen and osteogenic differentiation ability. Gene correction of the COL1A1 gene using CRISPR/Cas9 recovered the decreased type I collagen expression in OBs differentiated from OI-iPSCs. The osteogenic potential of OI-iPSCs was also recovered by the gene correction. This study suggests a new possibility of treatment and in vitro disease modeling using patient-derived iPSCs and gene editing with CRISPR/Cas9.

Pathogenic Role of Circulating Citrullinated Antigens and Anti-Cyclic Monoclonal Citrullinated Peptide Antibodies in Rheumatoid Arthritis

We examined whether it is possible to directly detect citrullinated antigens in the serum of rheumatoid arthritis (RA) patients using a monoclonal antibody (mAb) designed to be specific for citrullinated peptides. In order to confirm the potential of the mAb as a direct arthritis-inducing substance through experimental model of RA, a monoclonal antibody (mAb) 12G1 was generated using by immunization of mice with a challenging cyclic citrullinated peptide. Immunohistochemical analysis of RA-affected synovial tissue showed that our mAb 12G1 could indeed detect citrullinated proteins in target tissues. Subsequently, serum levels of citrullinated type II collagen and filaggrin were measured in healthy volunteers, patients with RA, ankylosing spondylitis (AS), and systemic lupus erythematosus (SLE) using a 12G1-based sandwich ELISA. This showed that citrullinated filaggrin showed 78.9% sensitivity and 85.9% specificity for RA diagnosis with a cutoff optical density (OD) value of 1.013, comparable with the results from a second-generation anti-citrullinated protein antibody (ACPA) test. Circulating citrullinated collagen and filaggrin were detected even in sera of RA patients who were negative for both rheumatoid factor (RF) and ACPA. ELISA results also showed that RF and ACPA titers showed significantly positive correlation with both citrullinated collagen and filaggrin OD values in sera of RA patients. 12G1 challenging aggravated the severity of murine arthritis. In summary, mAb 12G1 can directly detect citrullinated proteins in RA target tissue and in sera of RA patients and 12G1 showed direct arthritogenic potential in vivo. This, 12G1 might be useful for diagnosis of RA including seronegative RA and may help to elucidate the pathophysiological role of citrullination in RA.