Diminution of STING Expression in the Blood of Patients with Severe or Critical COVID-19 Pneumonia.

INTRODUCTION: Cytokine storm and critical COVID-19 pneumonia are caused in at least 10% of patients by inborn errors of or auto-Abs to type I IFNs. The pathogenesis of life-threatening COVID-19 pneumonia in other patients remains unknown. METHODS: This study was conducted at Masih Daneshvari Hospital, Tehran, Iran. In the period of study, 75 confirmed cases of COVID-19 with presentations ranging from mild upper respiratory tract infection to lower respiratory tract infection, including moderate, severe, and critical disease, were recruited. Expression of STING mRNA was measured in peripheral blood mononuclear cells (PBMCs) and compared between patients with different severity and outcome. RESULTS: There was a significant negative correlation between age and STING expression level (p value = 0.010). Patients with "severe to critical" illness had a 20-fold lower STING expression level compared to the "mild to moderate" group (p value = 0.001). Also, the results showed lower expressions of STING in the patients admitted to the ICU (p value = 0.015). Patients who finally died had lower expression of STING at the time of sampling (p value = 0.041). CONCLUSION: STING mRNA expression in PBMCs was significantly lower in older COVID-19 cases, the patients with more severe illness, who needed intensive care, and who eventually died.

The Possible Role of Bruton Tyrosine Kinase Inhibitors in the Treatment of COVID-19: A Review.

BACKGROUND: Coronavirus disease 2019 (COVID-19), an acute, sometimes severe respiratory illness caused by a novel coronavirus has led to a vast pandemic with an astonishing spread rate. Its treatment is unknown, its mortality is significant, and its socioeconomic complications are uncontrollable. Although there is still little known about the pathogenesis of the disease, severe cases of COVID-19 are usually associated with cytokine release syndrome and high serum levels of inflammatory cytokines, which are believed to be a major cause of mortality in these patients. Different pathways cause inflammation and the release of cytokines. One of these pathways is the Bruton tyrosine kinase (BTK) pathway, which is essential for the production of several anti-inflammatory cytokines. Theoretically, the inhibition of BTK signaling can reduce cytokine levels and subsequent anti-inflammatory effects. OBJECTIVE: This review aims to investigate the role of the BTK pathway in the pathogenesis of COVID-19 and the possible effects of its inhibition in the treatment of this disease. METHODS: This narrative review provides information regarding the use of BTK inhibitors in patients with COVID-19 and discusses whether clinicians should consider these medications while managing their patients based on the literature. Data were gathered using the PubMed, Scopus, and Web of Science databases. RESULTS: Some data support the use of BTK inhibitors for treating COVID-19. CONCLUSIONS: It is recommended that patients continue their medications in this class if they develop COVID-19 and were receiving these agents before the disease developed. The use of BTK inhibitors might enable patients to experience less severe immune responses to the COVID-19. Well-designed studies are needed to evaluate the effectiveness of BTKis in the management of COVID-19. (Curr Ther Res Clin Exp. 2022; 82:XXX-XXX) © 2022 Elsevier HS Journals.

Dynamic Changes of Lymphocyte Subsets in the Course of COVID-19.

BACKGROUND: Although the pathophysiology of coronavirus disease 2019 (COVID-19) is not clearly defined, among the proposed mechanisms, immune system dysfunction is more likely than others. The aim of this study was to clarify the characteristics and clinical significance of dynamic changes of lymphocyte subsets in the course of COVID-19. METHODS: In this prospective study, the levels of peripheral lymphocyte subsets including CD4+, CD8+, CD4+CD25+FOXP3+, CD38+, CD3+HLA-DR+, CD19+, CD20+, and CD16+CD56+ cells were measured by flow cytometry in 52 confirmed hospitalized patients with COVID-19 at the day of admission and after 7 days of care. Clinical response was defined as improvement in symptoms (fever, dyspnea, and cough as well as blood oxygen saturation), and patients who met these criteria after 1 week of admission were classified as early responders; others who survived and finally discharged from the hospital were classified as late responders and patients who died were categorized as nonresponders. Immunophenotyping of studied cell changes on the first day of admission and 7 days after treatment were compared. Besides, the correlation between cellular subset variation and clinical response and outcome were analyzed. RESULTS: Total counts of white blood cell, T cells, CD4+ T cells, CD8+ T cells, CD38+ lymphocytes, and CD3+HLA-DR+ lymphocytes were significantly increased in both early and late responders. No statistically significant difference was observed in CD4+/CD8+ ratio, B cells, FOXP3+Treg lymphocytes, and FOXP3 median fluorescence intensity among studied groups. According to the multivariate analysis, an increase in CD4+ T cells (p = 0.019), CD8+ T cells (p = 0.001), and administration of interferon (p < 0.001) were independent predictors of clinical response. CONCLUSION: We found an increasing trend in total T cells, T helpers, cytotoxic T cells, activated lymphocytes, and natural killer cells among responders. This trend was not statistically significant among nonresponders. The findings of this study may enhance our knowledge about the pathogenesis of COVID-19.

Immune cell profiling and antibody responses in patients with COVID-19.

BACKGROUND: Although there are a growing number of studies on evaluating lymphocyte subset counts as prognostic factors for COVID-19 disease severity, the lymphocyte subsets' analyses of both IgM and IgG responders and non-responders during the periods after onset of symptoms, have not been conducted yet. So, this study aimed to evaluate immune cell profiling of COVID-19 patients with and without antibody responses. METHODS: In this cross-sectional study, the levels of peripheral lymphocyte subsets were measured using flow cytometry in 53 patients with positive SARS-CoV-2 RT-PCR, for whom antibody testing of COVID-19 was performed. RESULTS: The white blood cell, neutrophil, and lymphocyte counts consistently decreased in the IgM and IgG non-responder group, while the differences in the median value between the two study groups were found to be statistically significant only in terms of neutrophil counts (P = 0.024 for IgM response and p-value = 0.046 for IgG response, respectively). Moreover, the level of neutrophil-to-lymphocyte ratio was observed to be significantly lower in the IgM or IgG non-responder group compared to the IgM or IgG responder group (3.6 ± 3.1 vs. 6.3 ± 4.2; p-value = 0.021). The patients with IgM antibody response had a significantly lower CD20+ lymphocytes (11% versus 15% in the groups without IgM antibody response, p-value = 0.031), The percentages of NK cells and CD4+ T cells significantly increased in the patients with IgG antibody response compared to those without IgG antibody response (13% versus 10%, p-value = 0.028, and 41.5% versus 34%; p-value = 0.03, respectively). Moreover, the patients who produced IgM or IgG antibody had significantly higher percentages of total T lymphocytes (64% versus 54%; p-value = 0.017), CD4+ T cells (41% versus 34%; p-value = 0.038), and NK cells (13% versus 9%, p-value = 0.023) compared to the group with no serological response. No significant difference was observed in the percentage of other lymphocyte subsets, including CD8+ T cells, Treg cells, and CD19+ B cells. CONCLUSION: Our results suggest that the total T cells, CD4+ T cells, and NK cells percentages are linked to serological response. Moreover, our findings suggested that neutrophil absolute counts and neutrophil-to-lymphocyte ratio may be valuable predictors of IgM or IgG antibody response.

Breast Tuberculosis in Iran: A Comprehensive Review.

ABSTRACT: Tuberculosis (TB) remains a significant global health concern and kills millions of people every year. While TB can affect any organ in the body, breast TB is relatively uncommon. This study presents a comprehensive review of literature spanning 23 years, with a focus on cases of breast TB in Iran. Among the 96 cases found, the majority (89.6%) fell within the age range of 20-60, with a striking prevalence among women (98.9%). Common symptoms included pain and palpable mass, each presenting in approximately 60.4% of cases. Notably, only a quarter of patients had a confirmed history of exposure to a known TB case. Left breast involvement was more prevalent (58.3%), with ipsilateral lymph node enlargement observed in 40.6% of cases. Given the clinical presentation of breast TB, which often leads to misdiagnosis, a significant proportion of cases (68.7%) were diagnosed through excisional biopsy. Following a standard 6-month regimen of anti-TB drugs, relapse occurred in only 4.2% of cases. This study highlights the need for heightened awareness and vigilance in diagnosing breast TB, especially in regions with a high burden. Although breast TB poses diagnostic challenges, with prompt identification and treatment, the prognosis is generally favorable, with a low incidence of relapse.

Mycobacterium genavense infections in immunocompromised patients with HIV: A clinical case report.

Key Clinical Message: It is essential to consider non-tuberculosis mycobacterium in HIV-positive patients with fever, abdominal pain, weight loss, and splenomegaly. Abstract: Mycobacterium genavense is an opportunistic slow-growing nontuberculous mycobacterium in patients with immunocompromised backgrounds, especially HIV-positive patients. In this study, we present two cases of Mycobacterium genovese infection in HIV-positive patients with a good clinical response to accurate treatment.

The Role of Laser and Microwave in Treatment of Endocrine Disorders: A Systematic Review.

Introduction: The treatment of endocrine problems like thyroid disease, diabetes mellitus (DM), and polycystic ovary syndrome (PCOS) faces significant challenges so that medical professionals worldwide try to find a new therapeutic approach. However, along with common treatments which include medications, hormone replacement therapy, and surgery; there is a growing interest in alternative therapies like laser therapy, which offers a non-invasive and unique technique for treating endocrine disorders alone or in combination with traditional methods. The main goal of this review was to do a systematic review on the role of the laser and Microwave in the treatment endocrine disorders. Methods: In the present systematic review, the most important databases, including PubMed, Scopus and Google Scholar, were searched for the studies examining the effect of lasers on the treatment of endocrine problems by using appropriate keywords and specific strategies from 1995 to 2023. All the studies that were not about lasers and endocrine were excluded. Results: Based on 51 reviewed studies, lasers and radiofrequency ablation such as RFA are effective in the treatment of thyroid diseases, hyperparathyroidism, pancreatic disorders, and sexual dysfunctions. Laser-induced interstitial thermal therapy (LITT) and microwave ablation (MWA) are genuine minimally invasive methods for the treatment of benign nodules, adenomas, and tumor ablation including pancreatic carcinomas and adrenal tumors. Intravenous laser blood irradiation (ILBI) which uses red, UV, and blue light could be effective in treating various metabolic disorders, such as DM. Conclusion: Laser as a cutting-edge and minimally invasive approach could treat various endocrine disorders. It has a great potential to treat and regulate hormonal imbalances, decrease inflammation, and relieve symptoms of various ailments, such as endocrine disorders.

Evaluation of Laser Intensity Effect on Photodynamic Therapy Efficacy.

Introduction: Intensity is one of the important parameters of laser radiation in photodynamic therapy. Effective treatment requires the selection of a suitable power of laser. This study aimed to evaluate laser effectiveness in photodynamic therapy via high and low intensity by the analysis of the gene expression profiles of the treated cells. Methods: The gene expression profiles of human SK-ChA-1 cells which are treated by 500mW and 50mW laser radiation were retrieved from the Gene Expression Omnibus (GEO) database. Data were assessed by the GEO2R program, and the significant differentially expressed genes (DEGs) were investigated via expression examination and protein-protein interaction (PPI) network analysis. Results: Analyses revealed that the higher intensity of radiation is associated with wide gene expression changes relative to the lower mode. 196 significant DEGs were identified and assessed. The extremely dysregulated DEGs except MMP1 were down-regulated. STAT1, IRF7, IL1B, DDX58, ISG15, RSAD2, DHX58, OASL, OAS1, STAT2, DDX60, OAS2, USP18, and IFI44L were introduced as hubs of the main component of the PPI network. Final analysis showed that STAT1, IRF7, IL1B, DDX58, and STAT2 are the critical DEGs. Conclusion: Compared to the 50 mW mode of radiation, 500 mW laser intensity effectively changed apoptosis, differentiation, cell proliferation and angiogenesis, regulation of other inflammation-related molecules, innate immunity, and maintaining immune homeostasis.

The Relationship between the Clinical Course of SARS-CoV-2 Infections and Expression of Bruton's Tyrosine Kinase.

OBJECTIVES: The Bruton tyrosine kinase (BTK), an important element for the production of several inflammatory cytokines, may play a role in the pathogenesis of COVID-19. The aim of this study was to investigate the level of BTK gene expression in COVID-19 cases based on the severity and the outcome of the disease. METHODS: In this study, 33 hospitalized patients with COVID-19 were recruited and were divided into two groups based on the severity of the disease: "mild to moderate" and "severe to critical". A blood sample was taken from each patient, peripheral blood mononuclear cells (PBMCs) were extracted, and BTK gene expression was measured. The level of BTK gene expression was compared based on the demographic data, laboratory results, and the severity and outcome of the disease. RESULTS: Among 33 patients, 22 (66.7%) were male. Nearly half of the cases had at least one underlying disease. According to the severity of the disease, 12 patients were in the "mild to moderate" group, and 21 were in the "severe to critical" group; eight (24.2%) eventually died. Age, weight, and BMI had no significant relationship with BTK expression. BTK expression was significantly lower in "severe to critical" and ICU-admitted cases and in subjects with low O2 saturation. There was no significant difference in BTK expression between cured and dead patients (p=0.117). CONCLUSION: BTK gene expression in PBMCs had an inverse relationship with the severity of the disease of COVID-19. However, no correlation between BTK expression and disease outcome was observed.

Broadening the phenotype and genotype spectrum of novel mutations in pontocerebellar hypoplasia with a comprehensive molecular literature review.

BACKGROUND: Pontocerebellar hypoplasia is an umbrella term describing a heterogeneous group of prenatal neurodegenerative disorders mostly affecting the pons and cerebellum, with 17 types associated with 25 genes. However, some types of PCH lack sufficient information, which highlights the importance of investigating and introducing more cases to further elucidate the clinical, radiological, and biochemical features of these disorders. The aim of this study is to provide an in-depth review of PCH and to identify disease genes and their inheritance patterns in 12 distinct Iranian families with clinically confirmed PCH. METHODS: Cases included in this study were selected based on their phenotypic and genetic information available at the Center for Comprehensive Genetic Services. Whole-exome sequencing (WES) was used to discover the underlying genetic etiology of participants' problems, and Sanger sequencing was utilized to confirm any suspected alterations. We also conducted a comprehensive molecular literature review to outline the genetic features of the various subtypes of PCH. RESULTS: This study classified and described the underlying etiology of PCH into three categories based on the genes involved. Twelve patients also were included, eleven of whom were from consanguineous parents. Ten different variations in 8 genes were found, all of which related to different types of PCH. Six novel variations were reported, including SEPSECS, TSEN2, TSEN54, AMPD2, TOE1, and CLP1. Almost all patients presented with developmental delay, hypotonia, seizure, and microcephaly being common features. Strabismus and elevation in lactate levels in MR spectroscopy were novel phenotypes for the first time in PCH types 7 and 9. CONCLUSIONS: This study merges previously documented phenotypes and genotypes with unique novel ones. Due to the diversity in PCH, we provided guidance for detecting and diagnosing these heterogeneous groups of disorders. Moreover, since certain critical conditions, such as spinal muscular atrophy, can be a differential diagnosis, providing cases with novel variations and clinical findings could further expand the genetic and clinical spectrum of these diseases and help in better diagnosis. Therefore, six novel genetic variants and novel clinical and paraclinical findings have been reported for the first time. Further studies are needed to elucidate the underlying mechanisms and potential therapeutic targets for PCH.

A case report of cutaneous infection with Mycobacterium neoaurum.

Cutaneous infection due to Mycobacterium neoaurum in immune-competent individuals had only been reported in limited cases. The point that makes our case very impressive was its cutaneous infection, and presentation in the immune-competent patient. Abstract: Cutaneous infections caused by nontuberculous mycobacteria usually occur in immunocompromised hosts. We report a rare case of cutaneous infection caused by Mycobacterium neoaurum in an immune-competent patient.

Molecular Communication Transmitter Design in Limited-Capacity Storage Regime.

The limited storage capacity at the transmitters of a molecular communication (MC) system can affect the system's performance. One of the reasons for this limitation is the size restriction of the transmitter, which the storage must be replenished so that the transmitter has enough molecules for future transmission. This paper proposes a biologically inspired transmitter model based on neurons for MC whose storage charging and discharging follow differential equations. The proposed transmitter opens its outlet for a specific time in each time frame to exponentially release a portion of stored molecules to code bit-1 and remains silent to code bit-0. We analyze our model based on different transmission parameters. These parameters are the symbol duration, the release time duration, the storage capacity, and the release and replenishment rate of the storage. We find that the storage outlet must be open for a certain period within the time slot duration in order to improve the performance of the proposed system. Additionally, we demonstrate that determining the effect of storage capacity size can be important for practical MC due to the significant differences between the ideal transmitter and the proposed one, which have a limited size. We show that increases in the transmitter storage size can improve the system performance. As a result, taking a closer look at these practical transmitters is essential to solving the problems and challenges of molecular communication systems.

Inverted ILM Flap Technique in Optic Disc Pit Maculopathy.

Purpose: To present the outcome of optic disc pit maculopathy (ODPM) managed successfully with an inverted internal limiting membrane (ILM) flap over the optic disc. A narrative review of ODPM pathogenesis and surgical management techniques are also provided. Case Report: This prospective interventional case series included three eyes of three adult patients (25-39 years old) with unilateral ODPM and a mean duration of unilaterally decreased visual acuity of 7.33 ± 2.40 months (4-12 months). The pars plana vitrectomy with posterior vitreous detachment induction was performed on eyes, followed by an inverted ILM flap insertion over the optic disc and gas tamponade. Patients were followed for 7-16 weeks postoperatively; best-corrected visual acuity (BCVA) improved dramatically in one patient from 2/200 to 20/25. BCVA in other patients improved two and three lines - to 20/50 and 20/30, respectively. A significant anatomical improvement was achieved in all three eyes, and no complication was detected throughout the follow-up period. Conclusion: Vitrectomy with inverted ILM flap insertion over the optic disc is safe and can yield favorable anatomical improvement in patients with ODPM.

Evaluation of the Cellular Resistance Process in Treated Cells Via Extracorporeal Photopheresis.

Introduction: Extracorporeal photopheresis (ECP) is a therapeutic method applied against some diseases such as cancers. Using 8-methoxypsoralen (8-MOP) and UVA radiation in ECP is associated with achievement in the treatment of patients with leukemic cutaneous T-cell lymphoma (CTCL). Evaluation of cellular resistance versus ECP is the aim of this study. Methods: Data were downloaded from the Gene Expression Omnibus (GEO) database and were analyzed via the GEO2R program. The significant DEGs were assessed via protein-protein interaction (PPI) network analysis by using the STRING database and Cytoscape software. The critical genes were evaluated via gene ontology by using the ClueGO application of Cytoscape software. The identified biological processes were determined and analyzed. Results: Fifty-seven significant DEGs were determined. The main connected component of the PPI network including 32 queried significant DEGs plus 50 first neighbors was constructed. Nineteen histones as critical nodes were assessed via gene ontology, and "nucleosome organization" was pointed out as the crucial biological process. Finally, 15 histones from H2A, H2B, and H3 histone families were identified as the key genes that are involved in the resistance property of the treated cells. Conclusion: In conclusion, 15 members of H2A, H2B, and H3 families (especially H2A family) were considered as the origin of resistance versus ECP treatment. It is concluded that sensitivity to ECP treatment depends on gross molecular events which are involved in the functions of histones.

Erratum: Inverted ILM Flap Technique in Optic Disc Pit Maculopathy.

[This corrects the article DOI: 10.18502/jovr.v18i2.13189.].

Hematocytological Clues of Peripheral Blood in Different Clinical Presentations of COVID-19.

Background: To gain insight into the pathogenesis and clinical course of COVID-19 from a historical perspective, we reviewed paraclinical diagnostic tools of this disease and prioritized the patients with a more severe form of disease admitted to intensive care units (ICUs). The objective was to better predict the course and severity of the disease by collecting more paraclinical data, specifically by examining the relationship between hematological findings and cytological variation of blood neutrophils and monocytes. Methods: This retrospective study was conducted on 112 patients with confirmed COVID-19 admitted to Imam Hossein Hospital (Tehran, Iran) from August to September 2020. Peripheral blood smears of these patients were differentiated according to several cytological variations of neutrophils and monocytes, and the correlation to the severity of the disease was specified. Results: The mean percentages of degenerated monocytes, degenerated granulocytes, and spiky biky neutrophils were significantly different among critical and non-critical patients (P<0.05). Degenerated monocytes and granulocytes were higher in critical patients as opposed to spiky biky neutrophils, which were higher among non-critical ones. Comparing the peripheral blood smears of COVID-19 patients (regarding pulmonary involvement in chest computed tomography [CT] scans [subtle, mild, moderate, and severe groups]), the twisted form of neutrophils was significantly higher in the subtle group than in the mild and moderate groups (P=0.003). Conclusion: Different cytological morphologies of neutrophils and monocytes, including degenerated monocytes, degenerated granulocytes, and spiky biky and twisted neutrophils, could help to predict the course and severity of the disease.

The Accuracy of Diagnosis and Genotyping of Leishmania Species Based on Spliced Leader Mini-Exon Gene by Nuclear Magnetic Resonance and Sequencing Assays.

Background: We aimed to evaluate the accuracy of genotyping of Leishmania species by the spliced leader mini-exon gene. Methods: Suspected leishmaniasis patients, referred to Masieh Daneshvary Hospital, Tehran, Iran were included from May 2017 to September 2021. The Leishmania species were genotyped by PCRRFLP based on the SL mini-exon gene and the ITS1 region of SSU-rRNA gene and compared with the sequencing results. The expressed metabolites of metacyclic promastigotes were evaluated by Proton nuclear magnetic resonance (1H-NMR). Results: Out of 66 suspected cases, 36 (54.4%) were positive for Leishmania species based on the PCR assays. In 21 (31.8%) cases, promastigotes grew on culture tubes. Based on the RFLP of SL RNA profile, 13 (19.7%) L. tropica, 9 (13.6%) L. major, 3 (4.5%) L. infantum, and 8 (12.1%) C. fasciculata isolates, isolated from culture media, were identified; however, 3 (4.5%) cases were unidentifiable due to the low number of parasites. Seventeen metabolites were expressed by the metacyclic forms of L. major, L. tropica and C. fasciculata isolates. The top differential metabolites expressed more in C. fasciculata were FAD, p-Methoxybenzyl alcohol and S-b-G-5, 5-G-b-S (A = CH2) (P<0.005) whereas Veratryl glycerols and D-(+)-Mannose were significantly increased in L. major and Betulin, LTyrosine in L. tropica (P<0.01). Conclusion: The invaluable techniques such as sequencing and 1H-NMR confirmed the results of genotyping of Leishmania species based on the SL mini-exon gene. SL mini exon gene can be used as a diagnostic tool to differentiate various Leishmania genotypes and detect contamination of culture media with C. fasciculata.

Assessment of Photosensitizer Concentration Effects on the Efficacy of Photodynamic Therapy.

Introduction: Photodynamic therapy (PDT) is an attractive approach in medicine. Due to its noninvasive nature and low side effects, PDT has been developed quickly. In the present study, the gene expression profiles of the human cell line that was treated via PDT in the sub-lethal concentration (LC50) and super-lethal concentration (LC90) of a photosensitizer (PS) from Gene Expression Omnibus (GEO) were extracted and the common differentially expressed genes (DEGs) were investigated. Methods: The gene expression profiles of the treated cells were compared with a control, and the common DEGs were determined. The common DEGs were assessed via protein-protein interaction (PPI) network analysis, and gene ontology enrichment was evaluated. The related biological terms for the common genes were identified. Results: Ninety-four common DEGs were selected to be analyzed. It appeared that the activation and increment of gene expression were prominent processes. Jun, Dusp1, Atf4, and Atf3 as four critical genes were highlighted. "Chromosomal and microsatellite instability in colorectal cancer" was identified as the main class of biological terms related to the assessed DEGs. Conclusion: The major molecular events which happened in both analyses indicated that PDT, independent from the concentration of PS, induced gross molecular changes such as the upregulation of Jun and Dusp1.

Collagen Synthesis as a Prominent Process During the Interval between Two Laser Sessions.

Introduction: Many people suffer from skin photodamage, especially photoaging. The application of a laser to repair damages is a common therapeutic method that is used widely. In the present study, the effectiveness and molecular mechanism of an Er:Glass non-ablative fractional laser on the human skin was assessed via bioinformatics and network analysis. Methods: The gene expression profiles of 17 white female forearm skins which received an Er:Glass non-ablative fractional laser before and after laser treatment in two sessions were extracted from Gene Expression Omnibus (GEO). Data were evaluated via GEO2R and the significant differentially expressed genes (DEGs) were assessed via protein-protein interaction (PPI) network analysis. The central nodes were identified and discussed for the compared set of samples. Results: Five classes of samples were clustered in two categories: first, baseline, 7 and 14 days after the first session of laser treatment, and second, one day after the first laser session, 29 days after the first laser session, and 1 day after the second laser session. The gross cell functions such as cell division and cell cycle and immune response were highlighted as the early affected targets of the laser. Collagen synthesis was resulted after the first laser session. Conclusion: In conclusion, the time interval between laser sessions plays a critical role in the effectiveness of laser therapy. Findings indicate that the gross effect of laser application appears in a short time, and important processes such as collagen synthesis happen later.