Thyroid cytology is a rapidly evolving field that has seen significant advances in recent years. Its main goal is to accurately diagnose thyroid nodules, differentiate between benign and malignant lesions, and risk stratify nodules when a definitive diagnosis is not possible. The current landscape of thyroid cytology includes the use of fine-needle aspiration for the diagnosis of thyroid nodules with the use of uniform, tiered reporting systems such as the Bethesda System for Reporting Thyroid Cytopathology. In recent years, molecular testing has emerged as a reliable preoperative diagnostic tool that stratifies patients into different risk categories (low, intermediate, or high) with varying probabilities of malignancy and helps guide patient treatment.

Hepatitis B virus (HBV) infection is a dynamic disease where patients progress through several stages defined by HBV e-antigen (HBeAg) status, HBV-DNA levels and transaminase elevations, with antiviral therapy indicated only in specific stages. However, some patients cannot be classified into one of the stages and are said to fall into an \'indeterminate phase\' or \'grey zone\'. Exact definitions of the indeterminate phase vary from guideline to guideline as a result of different cut-off values for biomarker measurements. Data suggest that as many as 50% of HBV patients may be in an indeterminate phase and may not rapidly transition out of this phase. Clinical data that suggest these patients are at increased risk of hepatocellular carcinoma (HCC) are complemented by molecular evidence of integrations of HBV-DNA into the host genome, chromosomal translocations and immune activation despite liver enzymes that may suggest lack of inflammation. Antiviral therapy reduces these hepatocarcinogenic mechanisms and is reflected in a reduction of fibrosis and HCC risk. We review key data on patients in the indeterminate phase, with emphasis on HCC as an outcome. We take a holistic approach and link new biological data with clinical observations as well as examine the potential role of antiviral therapy in reducing HCC risk among patients in the indeterminate phase. With the availability of safe and effective oral antivirals, consideration must be given as to how much residual risk of HCC should be tolerated among patients in the indeterminate phase.

UNASSIGNED: Radiofrequency ablation (RFA) is effective in the treatment of thyroid nodules, leading to a 50-90% reduction with respect to baseline. Current guidelines indicate the need for a benign cytology prior to RFA, though, on the other side, this procedure is also successfully used for the treatment of papillary microcarcinomas. No specific indications are available for nodules with an indeterminate cytology (Bethesda III/IV).
UNASSIGNED: To evaluate the efficacy of RFA in Bethesda III nodules without genetic alterations as verified by means of a custom panel.
UNASSIGNED: We have treated 33 patients (mean delivered energy 1069 ± 1201 J/mL of basal volume) with Bethesda III cytology, EU-TIRADS 3-4, and negative genetic panel. The mean basal nodular volume was 17.3 ± 10.7 mL.
UNASSIGNED: Considering the whole series, the mean volume reduction rate (VRR) was 36.8 ± 16.5% at 1 month, 59.9 ± 15.5% at 6 months, and 62 ± 15.7% at 1-year follow-up. The sub-analysis done in patients with 1 and 2 years follow-up data available (n = 20 and n = 5, respectively) confirmed a progressive nodular volume decrease. At all-time points, the rate of reduction was statistically significant (P < 0.0001), without significant correlation between the VRR and the basal volume. Neither cytological changes nor complications were observed after the procedure.
UNASSIGNED: RFA is effective in Bethesda III, oncogene-negative nodules, with reduction rates similar to those obtained in confirmed benign lesions. This procedure represents a good alternative to surgery or active surveillance in this particular class of nodules, regardless of their initial volume. A longer follow-up will allow to evaluate further reduction or possible regrowth.

Introduction Prior to immunosuppression, rheumatology patients are routinely screened for latent tuberculosis (TB) infection using interferon-gamma release assays (IGRAs). Variability in the management of latent and indeterminate IGRA results across institutions limited long-term outcome data. A retrospective study was conducted at Tawam Hospital, United Arab Emirates, to investigate the incidence and management protocols associated with positive and indeterminate IGRA results, as well as TB infection, among patients with rheumatic conditions. Methods A single-center retrospective observational study was performed at Tawam Hospital, Abu Dhabi, UAE. Ethical approval for this study was obtained from the Tawam Human Research Ethics Committee. Laboratory records and the hospital\'s electronic medical system were used to obtain information about IGRA results over a 12-year period (April 2010-April 2022). The hospital\'s electronic medical system was used to obtain patient information and subsequent management approaches of positive and indeterminate IGRAs. Moreover, long-term follow-up data were collected to determine the risk of TB reactivation in the cohort. Results We found a total of 1,012 positive and 223 indeterminate IGRA test results within the 12-year period. Within the rheumatology department, 123 positive and 39 indeterminate IGRA results were identified. In the indeterminate IGRA group, the majority were women (n = 24, 61.5%) and UAE nationals (n = 22, 56.4%), and their mean age was 38.6 years. Systemic lupus erythematosus was the most prevalent rheumatologic condition (n = 21, 53.8%). Thirteen (33.3%) were on disease-modifying anti-rheumatic drugs (DMARDs) and 26 (66.7%) were on corticosteroids during IGRA testing. A total of eight patients (20.5%) received anti-TB medications. In the positive IGRA group, the mean age was 55.7 years and the female-to-male ratio was 3:1. The most common rheumatologic condition was rheumatoid arthritis (n = 69, 56%). Sixty-five (52.8%) patients were on conventional DMARDs, 43 (34.9%) were on corticosteroids during IGRA testing, and 74 (60%) received anti-TB medications. Two cases (1.6%) of active TB infections were detected among patients with positive IGRA tests, both of whom were receiving anti-tumor necrosis factor alpha inhibitor treatment in combination with methotrexate. No cases of active TB infection were observed in the indeterminate IGRA group. Conclusion Long-term data on the risk of TB activation in positive and indeterminate IGRA results for rheumatological conditions are low. It is recommended to reassess the choice of using anti-TNF-α, with a positive IGRA result if no other feasible alternatives can be offered. Our findings stress the importance of age, underlying diseases, and immunosuppressive treatments in interpreting IGRA results and guiding patient management. A large multicenter study is needed to understand the differences and outcomes of such patients in TB endemic and nonendemic geographical areas.

Rapid HIV tests are critical to HIV surveillance and universal testing and treatment programs. We assessed longitudinal patterns in indeterminate HIV rapid test results in an African population-based cohort. Prospective HIV rapid antibody test results, defined by two parallel rapid tests, among participants aged 15-49 years from three survey rounds of the Rakai Community Cohort Study, Uganda, from 2013 to 2018, were assessed. An indeterminate result was defined as any weak positive result or when one test was negative and the other was positive. A total of 31,405 participants contributed 54,459 person-visits, with 15,713 participants contributing multiple visits and 7,351 participants contributing 3 visits. The prevalence of indeterminate results was 2.7% (1,490/54,469). Of the participants with multiple visits who initially tested indeterminate (n = 591), 40.4% were negative, 18.6% were positive, and 41.0% were indeterminate at the subsequent visit. Of the participants with two consecutive indeterminate results who had a third visit (n = 67), 20.9% were negative, 9.0% were positive, and 70.2% remained indeterminate. Compared to a prior negative result, a prior indeterminate result was strongly associated with a subsequent indeterminate result [adjusted prevalence ratio, 23.0 (95% CI = 20.0-26.5)]. Compared to men, women were more likely to test indeterminate than negative [adjusted odds ratio, 2.3 (95% CI = 2.0-2.6)]. Indeterminate rapid HIV test results are highly correlated within an individual and 0.6% of the population persistently tested indeterminate over the study period. A substantial fraction of people with an indeterminate result subsequently tested HIV positive at the next visit, underscoring the importance of follow-up HIV testing protocols.IMPORTANCERapid HIV tests are a critical tool for expanding HIV testing and treatment to end the HIV epidemic. The interpretation and management of indeterminate rapid HIV test results pose a unique challenge for connecting all people living with HIV to the necessary care and treatment. Indeterminate rapid HIV test results are characterized by any weak positive result or discordant results (when one test is negative and the other is positive). We systematically tested all participants of a Ugandan population-based, longitudinal cohort study regardless of prior test results or HIV status to quantify longitudinal patterns in rapid HIV test results. We found that a substantial fraction (>15%) of participants with indeterminate rapid test results subsequently tested positive upon follow-up testing at the next visit. Our findings demonstrate the importance of follow-up HIV testing protocols for indeterminate rapid HIV test results.

BACKGROUND: Interferon-gamma release assay (IGRA) is the main tool for the diagnosis of latent tuberculosis (TB) infection (LTBI). However, the indeterminate results were more frequent in children, and the underlying reasons were largely speculative. We aimed to compare QuantiFERON-TB Gold In-Tube (QFT-GIT) with X.DOT-TB (XDOT) for diagnosing LTBI, and to identify the risk factors associated with indeterminate results in children.
METHODS: A retrospective study for children<18 years old, at risk for LTBI or progression to TB disease, received either QFT-GIT or X.DOT-TB tests was performed at Beijing Children\'s Hospital from August 2019 to August 2022.
RESULTS: A total of 33,662 children were recruited, including 15,129 (44.9%) tested with X.DOT-TB and 18,533 (55.1%) with QFT-GIT. Proportion of positive and indeterminate results in children with respiratory disease was significantly higher than did that with other diseases, respectively (P < 0.001). The indeterminate rate of X.DOT-TB and QFT-GIT results decreased with increasing age (P < 0.001). Proportion of QFT-GIT indeterminate results was higher than that of X.DOT-TB across age groups. Male, age and disease classification all presented a statistically significant association with indeterminate IGRA results.
CONCLUSIONS: The positive rates of X.DOT-TB and QFT-GIT in children were 3.1% and 1.8%, respectively. The X.DOT-TB assay performed better than QFT-GIT in children, and male, age and underlying diseases were associated with an increased risk of indeterminate IGRA results.

The guidelines for the workup of thyroid nodules have been established in adult populations and secondarily applied to paediatric populations. In particular, The Bethesda System for Reporting Thyroid Cytopathology (TBSRTC) is commonly applied to both adult and paediatric thyroid nodules. However, as paediatric nodules have distinct molecular drivers and behavioural trajectories, there is renewed interest in diagnostic and management strategies that are paediatric specific. Here, we review key differences between paediatric and adult thyroid cancer and recent literature evaluating the use of TBSRTC in paediatric populations.

BACKGROUND: Human T-cell leukemia virus type 1 (HTLV-1) is a blood-borne virus, and mandatory testing of donated blood for HTLV-1 antibodies has been adopted by Japanese Red Cross blood centers since 1986. A confirmatory line immunoassay was initiated in 2019 for individuals who were seroreactive in the screening test. This decreased the incidence of indeterminate individuals, however, donors with indeterminate results are not informed of their HTLV-1 seroreactivity and they can continue to donate blood.
OBJECTIVE: To clarify the characteristics of indeterminate line immunoassay results among Japanese blood donors.
METHODS: Of 759,259 blood donors in the Kyushu district of Japan, an area endemic for HTLV-1, 101 cases were classified as indeterminate by line immunoassay testing. We examined these cases using alternative secondary antibodies, anti-human-Ig (IgG/IgM/IgA) and -IgM antibodies, to detect the early phase of HTLV infection.
RESULTS: Using anti-human-Ig and -IgM antibodies, HTLV infection status was confirmed in 37 individuals (HTLV-1-positive, 2; HTLV-positive, 27; HTLV-negative, 8). Among the remaining 64 indeterminate individuals, we identified one HTLV-2-infected 18-year-old female. A previous blood donation from this individual showed a negative anti-HTLV screening test result (signal-to-cutoff ratio = 0.1). Therefore, this case was considered to be an HTLV-2 seroconversion case.
CONCLUSIONS: These results indicate that the procedure for diagnosing HTLV infection should be reconsidered and that an accurate detection system for the early phase of HTLV infection is urgently needed for public health in Japan. Moreover, the issue of HTLV-2 infection needs a higher profile in Japan.

Background: Molecular testing for cytologically indeterminate thyroid nodules (ITNs) is often reported with incomplete data on clinical assessment and ultrasound malignancy risk (USMR) stratification. This study aimed to clinically validate the diagnostic accuracy of a novel molecular test, assess the incremental preoperative malignancy risk of other clinical factors, and measure the impacts of introducing molecular testing at the population level. Methods: Comprehensive clinical data were collected prospectively for the first 615 consecutive patients with ITNs in a centralized health care system following implementation of a reflexive molecular test. Clinical data include patient history, method of nodule discovery, clinical assessment, USMR, cytology, molecular testing, and surgery or follow-up along with surgeon notes on surgical decision-making. Accuracy of molecular testing and the impact of the introduction of molecular testing were calculated. A multivariable regression model was developed to identify which clinical factors have the most diagnostic significance for ITNs. Results: A locally developed, low-cost molecular test achieved a negative predictive value (NPV) of 76-91% [confidence interval, CI 66-95%] and a positive predictive value (PPV) of 46-65% [CI 37-75%] in ITNs using only residual material from standard liquid cytology fine-needle aspiration (FNA). Sensitivity was highest (80%; [CI 63-92%]) in the American Thyroid Association (ATA) intermediate-suspicion ultrasound category, and lowest (46%; [CI 19-75%]) in the ATA high-suspicion ultrasound category. Following implementation of molecular testing, diagnostic yield increased by 14% (p = 0.2442) and repeat FNAs decreased by 24% (p = 0.05). Mutation was the primary reason for surgery in 76% of resected, mutation-positive patients. High-risk mutations were associated with a 58% (p = 0.0001) shorter wait for surgery. Twenty-six percent of patients with a negative molecular test result underwent surgery. Multivariable regression highlighted molecular testing and USMR as significantly associated with malignancy. Conclusions: Molecular testing improves preoperative risk stratification but requires further stratification for intermediate-risk mutations. Incorporation of clinical factors (especially USMR) with molecular testing may increase the sensitivity for detection of malignancy. Introduction of molecular testing offers some clinical benefits even in a low resection rate setting, and directly influences surgical decision-making. This study illustrates the importance of the local diagnostic pathway in ensuring appropriate integrated use of molecular testing for best outcomes.

BACKGROUND: We implemented the QuantiFERON-TB Gold In-Tube (QFT-GIT) based on peripheral blood mononuclear cells (QFT-PBMCs) and QFT Gold Plus (QFT-Plus) in patients with indeterminate results, and use Mit-Nil value to identify false negatives and impaired cellular immunity.
METHODS: One hundred seventy-one out of 2480 patients who had a QFT-GIT test were prospectively recruited and classified as high Nil (n = 35), low Mit (n = 75) and control (n = 61) cohorts. Head-to-head comparisons, i.e., QFT-PBMCs vs. QFT-GIT in high Nil cohort, QFT-Plus vs. QFT-GIT in low Mit cohort, and QFT-PBMCs vs. QFT-GIT in controls, were performed. Lymphocyte subsets counts were conducted in low Mit and control cohorts.
RESULTS: A significant reduction of positive rate only occurred in Mit-Nil < 6 IU/ml (p < 0.001). QFT-PBMCs yielded 100 % valid results and had a significant Nil decline in high Nil cohort (0.98 ± 1.06 vs. 9.55 ± 0.64 IU/ml, p < 0.0001), while correlated well with QFT-GIT for qualitative (Cohen\'s k = 0.93) and quantitative (TB-Ag [R2 = 0.91] and Mit [R2 = 0.94]) analyses. QFT-Plus produced 61.3 % valid results and had a significant Mit increase in low Mit cohort (0.82 ± 0.95 vs. 0.17 ± 0.11 IU/ml, p < 0.0001). Mit-Nil value significantly correlated with lymphocyte subsets counts (R:0.49-0.56, p < 0.0001), separately corresponding to thresholds of 4.26, 5.33, 5.55 and 5.81 IU/ml for predicting decreased total lymphocyte, T lymphocyte, CD4+ and CD8+ cells.
CONCLUSIONS: QFT that replacing whole blood with PBMCs should be recommended to handle high Nil samples, and QFT-Plus can declined the frequency of low Mit results. In addition, Mit-Nil < 6 and 5.81 IU/ml are potential thresholds to identify the risk of false negatives and impaired cellular immunity, respectively.