Evaluating the Therapeutic Success of Keloids Treated With Cryotherapy and Intralesional Corticosteroids Using Noninvasive Objective Measures

Multimodal ultrasound assessment for monitoring keloid severity and treatment response

The current understanding and a standardized assessment or treatment guidelines for keloids are not fully established, highlighting the need for an objective method to gauge keloid severity and treatment outcomes. This study investigated the clinical utility of multimodal ultrasound, integrating Shear Wave Elastography (SWE) and Angio planewave ultrasensitive imaging (AP), to assess keloid severity and treatment responses in 58 keloids across 31 patients. Keloids were categorized into mild, moderate, and severe based on Vancouver Scar Scale (VSS) scores. The results revealed significant differences in keloid thickness, elasticity parameters, and blood flow levels among severity groups, with the AP technique demonstrated superior sensitivity in detecting keloid microcirculation. Additionally, the study evaluated the therapeutic response to Strontium-90 Yttrium-90 isotope applicator treatment in 28 keloids, categorizing them into 13 good responders and 15 poor responders based on improvements observed in their VSS scores. Good responders demonstrated marked improvements post-treatment, including significant flattening of the keloids, decreased stiffness, and normalization of blood flow levels. In contrast, poor responders exhibited minimal changes in keloid thickness, stiffness, and blood flow signals following treatment. These findings underscore the effectiveness of multimodal ultrasound in evaluating treatment responses in keloid management. In conclusion, multimodal ultrasound, focusing on SWE and AP modalities, offers a promising tool for comprehensive assessment, with potential to enhance keloid evaluation and track treatment responses across varying therapeutic interventions, thereby facilitating optimized clinical management and guiding personalized treatment. The study was successfully registered on ClinicalTrials.gov on 12/09/2023, with the Identifier NCT06034587.

Assessment of Treatment Modalities in Patients With Keloids: A Vancouver Scale Comparison

BACKGROUND

Various treatment modalities are used to treat keloids. However, a comprehensive assessment comparing the effectiveness of these modalities in terms of patient-reported outcomes is warranted.

OBJECTIVE

To assess and compare the effectiveness of various treatment modalities for keloids.

METHODS

We assessed treatment outcomes in a cohort of 250 patients diagnosed with keloids. The patients were categorized into four treatment groups: triamcinolone acetonide (TA), TA + cryotherapy, TA + pulsed dye laser (PDL), and TA + cryotherapy + PDL. The Vancouver Scar Scale was used to evaluate the keloid severity before and after treatment.

RESULTS

Significant differences were noted in the Vancouver Scale scores among the treatment groups (p=0.023). Notably, the TA + cryotherapy + PDL group exhibited the most substantial improvement in the Vancouver Scale scores, whereas the TA + PDL group showed the least difference. Pliability was the most significantly improved in the TA + cryotherapy + PDL group (p=0.039). Male patients experienced a greater reduction in pigmentation scores than female patients (p=0.037).

CONCLUSION

Our findings highlight the effectiveness of combined therapies, particularly TA + cryotherapy + PDL, in improving keloid-related parameters. These results offer valuable insights for clinicians in tailoring keloid treatment strategies and support the implementation of combination therapies for enhanced outcomes. This study underscores the importance of comprehensively assessing treatment modalities for keloid management. Combination therapies such as TA + cryotherapy + PDL irradiation have demonstrated significant promise in improving keloid characteristics.

Sele-targeted siRNA liposome nanoparticles inhibit pathological scars formation via blocking the cross-talk between monocyte and endothelial cells: a preclinical study based on a novel mice scar model

BACKGROUND

Pathological scars (PS) are one of the most common complications in patients with trauma and burns, leading to functional impairments and aesthetic concerns. Mechanical tension at injury sites is a crucial factor in PS formation. However, the precise mechanisms remain unclear due to the lack of reliable animal models.

RESULTS

We developed a novel mouse model, the Retroflex Scar Model (RSM), which induces PS by applying controlled tension to wounds in vivo. RNA sequencing identified significant transcriptome changes in RSM-induced scars. Elevated expression of E-Selectin (Sele) was observed in endothelial cells from both the RSM model and human PS (Keloid) samples. In vitro studies demonstrated that cyclic mechanical stretching (CMS) increased Sele expression, promoting monocyte adhesion and the release of pro-inflammatory factors. Single-cell sequencing analysis from the GEO database, complemented by Western blotting, immunofluorescence, and co-immunoprecipitation, confirmed the role of Sele-mediated monocyte adhesion in PS formation. Additionally, we developed Sele-targeted siRNA liposome nanoparticles (LNPs) to inhibit monocyte adhesion. Intradermal administration of these LNPs effectively reduced PS formation in both in vivo and in vitro studies.

CONCLUSIONS

This study successfully established a reliable mouse model for PS, highlighting the significant roles of mechanical tension and chronic inflammation in PS formation. We identified Sele as a key therapeutic target and developed Sele-targeted siRNA LNPs, which demonstrated potential as a preventive strategy for PS. These findings provide valuable insights into PS pathogenesis and open new avenues for developing effective treatments for pathological scars.

Ultrasound measurement of traumatic scar and skin thickness: a scoping review of evidence across the translational pipeline of research-to-practice

OBJECTIVES

To identify the ultrasound methods used in the literature to measure traumatic scar thickness, and map gaps in the translation of these methods using evidence across the research-to-practice pipeline.

DESIGN

Scoping review.

DATA SOURCES

Electronic database searches of Ovid MEDLINE, Embase, Cumulative Index of Nursing and Allied Health Literature and Web of Science. Grey literature searches were conducted in Google. Searches were conducted from inception (date last searched 27 May 2022).

DATA EXTRACTION

Records using brightness mode (B-mode) ultrasound to measure scar and skin thickness across the research-to-practice pipeline of evidence were included. Data were extracted from included records pertaining to: methods used; reliability and measurement error; clinical, health service, implementation and feasibility outcomes; factors influencing measurement methods; strengths and limitations; and use of measurement guidelines and/or frameworks.

RESULTS

Of the 9309 records identified, 118 were analysed (n=82 articles, n=36 abstracts) encompassing 5213 participants. Reporting of methods used was poor. B-mode, including high-frequency (ie, >20 MHz) ultrasound was the most common type of ultrasound used (n=72 records; 61% of records), and measurement of the combined epidermal and dermal thickness (n=28; 24%) was more commonly measured than the epidermis or dermis alone (n=7, 6%). Reliability of ultrasound measurement was poorly reported (n=14; 12%). The scar characteristics most commonly reported to be measured were epidermal oedema, dermal fibrosis and hair follicle density. Most records analysed (n=115; 97%) pertained to the early stages of the research-to-practice pipeline, as part of research initiatives.

CONCLUSIONS

The lack of evaluation of measurement initiatives in routine clinical practice was identified as an evidence gap. Diverse methods used in the literature identified the need for greater standardisation of ultrasound thickness measurements. Findings have been used to develop nine methodological considerations for practitioners to guide methods and reporting.

Progress in the clinical treatment of keloids

Keloid is a pathological scar that is higher than the skin surface following skin damage. Its lesion range often extends beyond the original damage boundary and does not naturally subside over time. Its pathogenesis is very complex, currently the main causes include fibroblast excessive proliferation, collagen and extracellular matrix (Extracellular matrix, ECM) excessive deposition, excessive angiogenesis, and so on. The traditional treatment method primarily involves surgical intervention, but it is associated with a high recurrence rate post-surgery. Consequently, many treatment methods are derived according to the different clinical characteristics of keloid. This paper will review the therapeutic progress in recent years from surgical treatment, physiotherapy, drug therapy, and biological therapy, with the goal of offering valuable insights for the clinical treatment of keloids.

Scars

Wound healing occurs as a response to disruption of the epidermis and dermis. It is an intricate and well-orchestrated response with the goal to restore skin integrity and function. However, in hundreds of millions of patients, skin wound healing results in abnormal scarring, including keloid lesions or hypertrophic scarring. Although the underlying mechanisms of hypertrophic scars and keloid lesions are not well defined, evidence suggests that the changes in the extracellular matrix are perpetuated by ongoing inflammation in susceptible individuals, resulting in a fibrotic phenotype. The lesions then become established, with ongoing deposition of excess disordered collagen. Not only can abnormal scarring be debilitating and painful, it can also cause functional impairment and profound changes in appearance, thereby substantially affecting patients' lives. Despite the vast demand on patient health and the medical society, very little progress has been made in the care of patients with abnormal scarring. To improve the outcome of pathological scarring, standardized and innovative approaches are required.

Keloid treatments: an evidence-based systematic review of recent advances

BACKGROUND

Keloids are pathologic scars that pose a significant functional and cosmetic burden. They are challenging to treat, despite the multitude of treatment modalities currently available.

OBJECTIVE

The aim of this study was to conduct an evidence-based review of all prospective data regarding keloid treatments published between 2010 and 2020.

METHODS

A systematic literature search of PubMed (National Library of Medicine), Embase (Elsevier), and Cochrane Library (Wiley) was performed in November of 2020. Search strategies with the keywords "keloid" and "treatment" were performed by a medical librarian. The search was limited to prospective studies that were peer-reviewed, reported on clinical outcomes of keloid therapies, and were published in the English language between January 1, 2010, and November 24, 2020.

RESULTS

A total of 3462 unique citations were identified, of which 108 studies met inclusion criteria. Current literature supports silicone gel or sheeting with corticosteroid injections as first-line therapy for keloids. Adjuvant intralesional 5-fluorouracil (5-FU), bleomycin, or verapamil can be considered, although mixed results have been reported with each. Laser therapy can be used in combination with intralesional corticosteroids or topical steroids with occlusion to improve drug penetration. Excision of keloids with immediate post-excision radiation therapy is an effective option for recalcitrant lesions. Finally, silicone sheeting and pressure therapy have evidence for reducing keloid recurrence.

CONCLUSIONS

This review was limited by heterogeneity of subject characteristics and study outcome measures, small sample sizes, and inconsistent study designs. Larger and more robust controlled studies are necessary to further understand the variety of existing and emerging keloid treatments, including corticosteroids, cryotherapy, intralesional injections, lasers, photodynamic therapy, excision and radiation, pressure dressings, and others.

Octenidine Versus Dispase Gels for Wound Healing After Cryosurgery Treatment in Patients with Basal Cell Carcinoma

For a specific group of patients with basal cell carcinoma (small, low risk), cryosurgery could be the suggested treatment, which results in the formation of an ulcer in the lesion area. The proteolytic enzymes' contribution to the wound healing is an ongoing research goal. Preclinical animal experiments in the Laboratory of the Pharmaceutical Technology Department of the National and Kapodistrian University of Athens have showed that a dose of 5 U/mL of dispase gel after the formation of tissue rashes, significantly promoted wound healing. Herein, a feasibility study in 16 patients enrolled by the First Department of Dermatology of Andreas Syggros Hospital was designed: 5 U/mL of dispase gel (once every 3 days) versus a drug reference containing octenidine (daily administration). The evaluation of the healing effect, safety, and tolerance was done on days 1 (cryosurgery), 2, 7, 21, and 60. The study end point was considered either the ulcer complete healing or the eighth week since treatment initiation. Wound healing was faster with dispase gel and hemoglobin reduced rapidly after the seventh day. Yet, hydration was higher in the control group. Our non-parametric analysis provides evidence that the dispase gel shows faster healing compared to the reference drug, in humans, meriting further investigation in larger human sample sizes before massive production of the product.

Emerging High-Frequency Ultrasound Imaging in Medical Cosmetology

Cosmetic skin diseases are a part of many dermatological concerns brought up by patients, which negatively affect mental health and quality of life. Imaging technology has an established role in the diagnosis of cosmetic skin diseases by recognizing information on deep skin lesions. Due to the complex physiological and pathological nature of cosmetic skin diseases, the diagnostic imaging performance varies greatly. Developing noninvasive technology models with wide applicability, particularly high-frequency ultrasound (HFUS), which is able to achieve high-resolution imaging of the skin from the stratum corneum down to the deep fascia, is of great significance to medical cosmetology. To explore the great potential of HFUS in cosmetic skin diseases, a narrative review of literature from PubMed and Web of Science published between 1985 and 2022 was conducted. This narrative review focuses on the progression of HFUS imaging in medical cosmetology, especially on its promising application in the quantitative evaluation and differential diagnosis of cutaneous pathological scar, port wine stain (PWS), acne, skin aging, and other cosmetic applications.

Analysis of the expression of FAP-α protein in 2D-keloid fibroblast cultures and in 3D models of keloid

OBJECTIVE

Keloids arise most often as a result of abnormal wound healing. The lesion characterizes inflammation and fibroproliferation. Fibroblast activation protein alpha (FAP-α) is one of enzymes engaged in keloid formation. It is serine protease that facilitates cells invasion and growth. FAP-α possess also non-enzymatic activity and plays role in activation of cell signaling. The aim of the study was to assess the impact of culture conditions on the proliferation of keloid fibroblasts and the expression of FAP-α. Analysis of utility of 3D models of keloid in in vitro study of pathogenesis of keloids was also made.

METHODS

NHDF and KEL FIB cells were cultured in vitro in 2D cultures and 3D Matrigel models. The viability of cells was assayed spectrophotometrically with WST-1 test. FAP-α protein amount in cell cultures and 3D models was evaluated with the use of ELISA test.

RESULTS

KEL FIB fibroblasts exhibited higher viability than NHDF fibroblasts in all three models of keloid. The expression of FAP-α is different in normal and keloid fibroblasts. In vitro conditions influence the expression of FAP-α in NHDF cells but not in KEL FIB cells.

CONCLUSIONS

This preliminary study has shown that the expression of FAP-α, similarly to other enzymes engaged in keloid formation, is different in keloids in vivo and in in vitro models. FAP-α expression is modulated by in vitro conditions in normal fibroblasts but not in keloid fibroblasts.

Efficacy and safety of botulinum toxin type A for postoperative scar prevention and wound healing improvement: A systematic review and meta-analysis

BACKGROUND

Botulinum toxin type A (BTXA) has shown underlying effects for wound healing improvement. New small clinical trials keep emerging every year and updated evidence-based information is warranted. This study aimed to evaluate the efficacy and safety of BTXA for preventing scarring.

METHODS

Four databases were searched to recruit randomized clinical trials (RCTs) which compared the surgical wounds treated with BTXA vs. those treated with placebo or blank control. The outcomes were primarily quantified by measures including the Vancouver Scar Scale (VSS), Visual Analog Scale (VAS), Stony Brook Scar Evaluation Scales (SBSES), modified SBSES (mSBSES), and scar width. Patients' satisfaction and adverse events were also reported.

RESULTS

In total, 16 RCTs involving 671 cases (510 patients) were included. The outcome showed significant superiority of BTXA in VSS (mean difference [MD] = -1.32, 95% confidence interval [CI]: -2.00 to -0.65, p = 0.0001), VAS (MD = 1.29, 95% CI: 1.05-1.52, p < 0.00001), SBSES or mSBSES (MD = -0.18, 95% CI: -0.27 to -0.10, p < 0.0001), scar width (MD = -0.18, 95% CI: -0.27 to -0.10, p < 0.0001), and patients' satisfaction (risk ratio [RR] = 1.25, 95% CI: 1.06-1.49, p = 0.01). No significant difference of adverse events incidence was observed (RR = 1.46 95% CI: 0.64-3.33, p = 0.36).

CONCLUSIONS

Botulinum toxin type A is effective and safe for postoperative scar prevention and wound healing improvement, especially for facial wounds of Asians. Further studies should manage to standardize the treatment algorithm, while mSBSES is recommended for scar assessment.

Correlation between elastic modulus and clinical severity of pathological scars: a cross-sectional study

Though widely used to assess pathological scars, the modified Vancouver Scar Scale (mVSS) is neither convenient nor objective. Shear wave elastography (SWE) is used to evaluate the stiffness of pathological scars. We aimed to determine the correlation between mVSS score and elastic modulus (EM) measured by SWE for pathological scars. Clinical information including ultrasound (US) results of the enrolled patients with pathological scars was analyzed. The clinical severity of the pathological scars was evaluated by mVSS. Skin stiffness, as represented by EM, was calculated using SWE. The average EM of the whole scar (EM_WHOLE), hardest part of the scar (EM_HARDEST), and normal appearance of the skin around the scar (EM_NORMAL) were also recorded. Enrolled in this study were 69 pathological scars, including 28 hypertrophic scars and 41 keloids. The univariable regression analyses showed that the EM of pathological scars was closely related to mVSS score, while the linear multivariable regression analyses showed no significantly correlation. Curve fitting and threshold effect analysis revealed that when EM_WHOLE was less than 166.6 kPa or EM_HARDEST was less than 133.07 kPa, EM was positively correlated with mVSS score. In stratified analysis, there was no significant linear correlation and threshold effect between EM_WHOLE and mVSS score in hypertrophic scars or keloids. However, the fully adjusted smooth curves presented a linear association between mVSS score and EM_HARDEST in keloids (the adjusted β [95% CI] was 0.010 [0.001, 0.018]), but a threshold and nonlinear association were found in hypertrophic scars. When EM_HARDEST was less than 156.13 kPa, the mVSS score increased along with the hardest scar part stiffness; the adjusted β (95% CI) was 0.024 (0.009, 0.038). In conclusion, EM of pathological scars measured by SWE were correlated with mVSS within a threshold range, and showed different association patterns in hypertrophic scars and keloids.

Activity of keloids evaluated by multimodal photoacoustic/ultrasonic imaging system

Multiple objective assessments have been used to assess the activity of keloids to compare different therapeutic regimens and facilitate the best individual treatment choice for patients, but none of them are standardized. A multimodal photoacoustic/ultrasonic (PA/US) imaging system, including photoacoustic imaging, elastography, ultra-micro-angiography, and conventional US technologies (gray scale US, color Doppler US, and power Doppler US), was applied to evaluate keloids by a radiologist. Growing stages were defined by patients, and Vancouver Scar Scale (VSS) was assessed by a plastic surgeon. A comprehensive model based on multimodal ultrasound parameters (poor-echo pattern, high vascular density, decreased elasticity, and low SO₂ within the keloid) and VSS might be a potential indicator of active keloids, comparing with VSS alone. The multimodal PA/US imaging system could be a promising technique for keloids assessment.

Cryosurgery as a Single Agent and in Combination with Intralesional Corticosteroids Is Effective on Young, Small Keloids and Induces Characteristic Histological and Immunohistological Changes: A Prospective Randomized Trial

BACKGROUND

As the pathogenesis of keloids is poorly understood, there is no sound biological basis of keloid management. Few controlled therapeutic studies have been published, and recurrences are a major reason for treatment failure.

OBJECTIVE

To detect efficacy and safety of cryosurgery regimens on keloids and the occurring biological changes caused by the treatment.

METHODS

This prospective randomized study compared efficacy and tolerability as well as histological/immunohistochemical effects of liquid nitrogen contact cryosurgery as a single regimen (group A) and combined with intralesional corticosteroids (group B) on young (<2 years old), small (≤10 cm2) keloids in 40 patients (2-sided effect, α-error 1%, power 95%).

RESULTS

Marked flattening of the lesions was achieved by both regimens. Median lesional volumes decreased from 106 to 7 mm3 in group A (p = 0.001) and from 138 to 6 mm3 in group B (p < 0.0001; ns, between groups). Good to excellent responses were registered in 83.3 and 90% of patients in groups A and B, respectively, by evaluating the lesional volume, in 80 and 95% of patients by the physician's evaluation and in 95% of patients in either group by the patient's assessment. Follow-up of 6-36 months revealed no further significant changes. Cryosurgery was generally well tolerated, with minor pain during treatment not requiring (27.5%) or requiring local anaesthesia (5%) - but not analgesics -, and hypopigmentation (25%). Histological examination showed increased vessel number and lumen dilatation after treatment in group B and reduction of rete ridge length in both groups with more prominent changes in group A. Tenascin C staining demarcated keloids from normal skin before therapy, while after therapy the entire treated tissue was labelled. Interferon-γ expression was significantly decreased after therapy both regarding positively stained cells and intensity in both groups.

CONCLUSION

Cryosurgery without and with intralesional corticosteroids is effective and safe on young, small keloids not only as a destructive physical procedure, but also by inducing biochemical and immunological scar rejuvenation.

Assessing keloid recurrence following surgical excision and radiation

Keloids are a fibroproliferative disorder that can result from a cutaneous injury to the reticular dermis. Recurrence rates as high as 100% have been reported following surgical excision alone. Consequently, a variety of post-surgical techniques have been employed to prevent keloid recurrence, including the use of radiation. Although numerous studies have shown post-excisional X-rays, electron beam, lasers and brachytherapy can reduce the rate of keloid recurrence, numerous inconsistencies, including a wide range of definitions for keloid recurrence, make it difficult to compare study outcomes. The review aims to examine the various means for defining keloid recurrence in clinical trials involving the use of radiation therapy. Searches of the Cochrane Library and PubMed were performed to identify the available information for post-surgical keloid recurrence following radiation therapy. Each identified study was reviewed for patient follow-up and criteria used to define keloid recurrence. The search results included clinical studies with external beam radiation, brachytherapy and superficial radiation therapy. Many studies did not include a definition of keloid recurrence, or defined recurrence only as the return of scar tissue. Other studies defined keloid recurrence based on patient self-assessment questionnaires, symptoms and scar elevation and changes in Kyoto Scar Scale, Japan Scar Workshop Scale and Vancouver Scar Scale scores. The results of this review indicate keloidectomy followed by radiation therapy provide satisfactory recurrence rates; however, clinical studies evaluating these treatments do not describe treatment outcomes or use different definitions of keloid recurrence. Consequently, recurrence rates vary widely, making comparisons across studies difficult. Keloid recurrence should be clearly defined using both objective and subjective measures.

Treatment of keloids using 5-fluorouracil in combination with crystalline triamcinolone acetonide suspension: evaluating therapeutic effects by using non-invasive objective measures

BACKGROUND

Intralesional 5-fluorouracil (5-FU) in combination with triamcinolone acetonide (TAC) has been recommended as a promising alternative for keloids not responding to silicone-based products, cryotherapy or intralesional corticosteroids alone. Although numerous studies support the efficacy of this regime, there is a lack of objective data.

OBJECTIVES

In this study, we evaluate the therapeutic effect of four courses of intralesional 5-FU in combination with TAC (3 : 1) utilizing 3D analysis (PRIMOS^®pico ), ultrasound and scar scales such as the Patient and Observer Scar Assessment Scales (POSAS) and the Dermatology Life Quality Index (DLQI).

METHODS

Twenty-five patients with keloids were treated using 5-FU and TAC every 4 weeks. Objective assessments were performed and the scar scales administered at baseline, as well as during consecutive visits at 1- and 12-month follow-up (FU). Routine laboratory tests were performed at baseline and at 1-month FU.

RESULTS

3D PRIMOS and ultrasound measurements revealed highly significant and stable reductions in height (baseline mean score: 4.0 ± 1.7 mm, 1-month FU mean score: 1.5 ± 0.8 mm, 12-month FU mean score: 1.8 ± 0.9 mm, P = <0.0001), volume (baseline mean score: 1,105 ± 911.5 mm³ , 1-month FU mean score: 416.1 ± 218.1 mm³ , 12-month FU mean sore: 431.2 ± 253.6 mm³ , P = <0.0001, respectively) and penetration depth of keloids (relative reduction between baseline and 12-month FU of 74.4%, P = <0.0001). The POSAS and DLQI scales confirmed significant objective and subjective improvements in scar appearance in all categories. The life quality associated with keloid appearance improved from a 'moderate effect' to a 'small effect' throughout the course of the study.

CONCLUSIONS

Results of this study confirm the efficacy and safety of the combination of 5-FU and TAC in keloids. Treatments were well tolerated and demonstrated stable results at 12-month FU.

Quantitative assessment of treatment efficacy in keloids using high-frequency ultrasound and shear wave elastography: a preliminary study

The purpose of this study was to investigate the performance of high-frequency ultrasound (HFUS) and shear wave elastography (SWE) in the quantitative evaluation of therapeutic responses of keloids. 43 patients with 76 keloids were recruited into this study. In keloids and symmetrical sites, the skin thickness was measured using HFUS and skin stiffness expressed as elastic moduli (Young's modulus and shear wave velocity) was measured using SWE. The coefficient of variation values were calculated by using difference values of skin elastic moduli and skin thickness. A significant increase of both skin stiffness and thickness appeared in pre-treated keloids compared with post-treated keloids (P < 0.001) and normal controls (P < 0.001), respectively. Stiffness in post-treated keloids and normal skins was significantly different (P < 0.001), while the difference in thickness measurements showed no significance (P = 0.56, >0.05). The coefficient of variation of Young's modulus was the highest when compared between (i) pre-treated keloids and theirs site-matched areas; (ii) pre-treated and post-treated keloids. SWE, which showed greater ability in determining the extent of keloids recovery, may provide an ideal tool to assess the stiffness of keloids and theirs therapeutic response.