Axillary lymphadenitis in adults presents a diagnostic challenge due to its diverse etiology and variable clinical manifestations. We present a rare case of suppurative Group A Streptococcus (GAS) axillary lymphadenitis secondary to a puncture wound, emphasizing the critical importance of differential diagnosis and immediate intervention. A 36-year-old male initially presented with left axillary pain and discomfort following a traumatic injury to the left thumb. Despite multiple healthcare encounters and misdiagnoses including viral illness and shingles, the patient\'s condition deteriorated, manifesting as fever, edema, and erythema in the left axilla. This case underscores the paramount significance of considering lymphadenitis in patients with axillary symptoms, particularly following trauma or skin breaches. Early recognition and appropriate management are crucial to prevent grave complications such as abscess formation, thrombophlebitis, and bacteremia. Streptococcal axillary lymphadenitis should be included at the forefront of the differential diagnosis to expedite treatment and mitigate potential life-threatening consequences associated with delayed diagnosis.

Group A streptococcus pyogenes (GAS) is a common organism that can cause upper respiratory infections. We encountered a case where GAS caused infective endocarditis (IE) due to an entry from the vagina. In this case, although echocardiography was negative, we were able to make a diagnosis of IE based on the 2023 Duke International Society for Cardiovascular Infectious Diseases Criteria, and we started antimicrobial therapy for IE. However, the patient subsequently developed persistent abdominal pain, which was atypical; hence, we reviewed the differential diagnosis. It is difficult to locate the primary site of infection because GAS rarely causes vaginal infections, and vaginal infections rarely cause IE. This case highlights the significance of revisiting medical history and the value of using a system 3 approach to refine diagnostic directions.

Objective: To analyze the characteristics of super-antigen (SAg) of group A Streptococcus pyogenes (GAS), isolated from patients with scarlet fever or pharyngeal infections in Beijing between 2015-2017. Methods: Throat swab specimens from patients with scarlet fever or pharyngeal infections were collected and tested for GAS. Eleven currently known SAg genes including SpeA, speC, speG, speH, speI, speJ, speK, speL, speM, smeZ and ssa were tested by real-time PCR while M protein genes (emm genes) were amplified and sequenced by PCR. Results: A total of 377 GAS were isolated from 6 801 throat swab specimens, with the positive rate as 5.5%. There were obvious changes noticed among speC, speG, speH and speK in three years. A total of 45 SAg genes profiles were observed, according to the SAgs inclusion. There were significant differences appeared in the frequencies among two of the highest SAg genes profiles between emm1 and emm12 strains (χ(2)=38.196, P<0.001; χ(2)=72.310, P<0.001). There also appeared significant differences in the frequencies of speA, speH, speI and speJ between emm1 and emm12 strains (χ(2)=146.154, P<0.001; χ(2)=52.31, P<0.001; χ(2)=58.43, P<0.001; χ(2)=144.70, P<0.001). Conclusions: Obvious changes were noticed among SAg genes including speC, speG, speH and speK from patients with scarlet fever or pharyngeal infections in Beijing between 2015-2017. SAg genes including speA, speH, speI and speJ appeared to be associated with the emm 1 and emm 12 strains. More kinds of SAg genes profiles were isolated form GAS but with no significant differences seen in the main SAg genes profiles, during the epidemic period.
目的： 分析2015－2017年北京市猩红热及咽部感染患者A组链球菌（GAS）超抗原基因特征。 方法： 采集猩红热及咽部感染患者咽拭子标本进行GAS分离鉴定，采用实时荧光PCR法检测超抗原基因（speA、speC、speG、speH、speI、speJ、speK、speL、speM、smeZ和ssa），PCR法扩增后测序确定GAS的emm基因型别。 结果： 2015年5月至2017年7月采集的6 801份咽拭子标本中共分离到377株GAS菌株（阳性率5.5%）。超抗原基因speC、speG、speH和speK的检出率3年间出现较明显变化。共检测到45种超抗原基因谱，占比较高的2种超抗原基因谱在emm1和emm12型间分布差异均有统计学意义（χ(2)=38.196，P<0.001；χ(2)=72.310，P<0.001）。超抗原speA、speH、speI和speJ在emm1和emm12型GAS间分布差异均有统计学意义（χ(2)=146.154，P<0.001；χ(2)=52.31，P<0.001；χ(2)=58.43，P<0.001；χ(2)=144.70，P<0.001）。 结论： 2015－2017年北京市猩红热及咽部感染患者GAS超抗原基因speC、speG、speH和speK的检出率有较明显变化，speA、speH、speI和speJ在emm1和emm12基因型之间的分布存在差异，GAS菌株所携带的超抗原基因谱更宽，但主要流行谱未发生改变。.

Pediatric autoimmune neuropsychiatric disorders associated with streptococcal infections (PANDAS) are hypothesized to occur as a result of cross-reactive antibodies produced in response to group A streptococcal infections. Previous research suggests that immunomodulatory therapies, such as intravenous immunoglobulin (IVIG), may lead to rapid and sustained symptom improvement in patients with PANDAS.
A total of 35 children meeting criteria for PANDAS and moderate to severe obsessive-compulsive disorder (OCD) were enrolled in a randomized-entry, double-blind, placebo-controlled, 6-week trial of IVIG (1 g/kg/day on 2 consecutive days), followed by optional open-label treatment for nonresponders, with follow-up at 12 and 24 weeks. Primary outcome measures were the Children\'s Yale-Brown Obsessive Compulsive Scale (CY-BOCS) and the Clinical Global Impressions-Improvement (CGI-I) rating. \"Responders\" were defined, a priori, by a ≥ 30% decrease in CY-BOCS total score, and a \"much\" or \"very much\" improved rating on CGI-I.
During the double-blind phase, the mean decrease in CY-BOCS score was 24% ± 31% in the IVIG group (n = 17) and 12% ± 27% in the placebo group (n = 18), with six responders in the IVIG group (35%) versus four (22%) in the placebo group; these differences were not statistically significant. Twenty-four participants met criteria for nonresponse to double-blind infusion and received open-label IVIG at week 6. Among all participants, the mean CY-BOCS improvement from baseline was 55% ± 33% at week 12 and 62% ± 33% at week 24.
IVIG was safe and well tolerated. Between-group differences were smaller than anticipated, and the double-blind comparison failed to demonstrate superiority of IVIG over placebo. The observed open-label improvements indicate that future trials would benefit from larger sample sizes designed in part to aid in the identification of biomarkers predictive of a positive response to immunotherapy. Future investigations focused on the natural history of PANDAS are also warranted. Clinical trial registration information-Intravenous Immunoglobulin for PANDAS (Pediatric Autoimmune Neuropsychiatric Disorders Associated With Streptococcal Infections); http://clinicaltrials.gov/; NCT01281969ZIAMH002666.

Complement is undeniably quintessential for innate immunity by detecting and eliminating infectious microorganisms. Recent work, however, highlights an equally profound impact of complement on the induction and regulation of a wide range of immune cells. In particular, the complement regulator CD46 emerges as a key sensor of immune activation and a vital modulator of adaptive immunity. In this review, we summarize the current knowledge of CD46-mediated signalling events and their functional consequences on immune-competent cells with a specific focus on those in CD4(+) T cells. We will also discuss the promises and challenges that potential therapeutic modulation of CD46 may hold and pose.