Ovarian Low-grade Basaloid Carcinoma Arising in Brenner Tumor: A New Variant of Malignant Brenner Tumor.

Brenner tumors are uncommon ovarian neoplasms, most of which are benign, although borderline and malignant variants occur. We report 2 unusual ovarian neoplasms composed of an admixture of typical benign Brenner tumor and a low-grade epithelial neoplasm which we designate as low-grade basaloid carcinoma. The latter component morphologically and immunohistochemically resembled "salivary gland-type/myoepithelial" neoplasms with variable positive staining with cytokeratins, p63, S100, and CD117. One tumor exhibited aggressive behavior with local recurrence and distant metastasis. This neoplasm exhibited focal "high-grade" transformation with diffuse mutation-type p53 staining, in contrast to the wild-type immunoreactivity in the low-grade component. As far as we are aware, such neoplasms have not previously been reported in the literature and this represents a newly described morphologic variant of malignant Brenner tumor.

UTP is a regulator of in vitro and in vivo angiogenic properties of cardiac adipose-derived stem cells.

The ability of cardiac adipose-derived stem cells (cADSC) to differentiate into multiple cell types has opened new perspectives in cardiac cell-based regenerative therapies. P2Y nucleotide receptors have already been described as regulators of adipogenic differentiation of cADSC and bone marrow-derived stem cells. In this study, we defined UTP as a regulator of cADSC endothelial differentiation. A daily UTP stimulation of cADSC during endothelial predifferentiation increased their capacity to form an endothelial network in matrigel. Additionally, pro-angiogenic UTP target genes such as epiregulin and hyaluronan synthase-1 were identified in predifferentiated cADSC by RNA sequencing experiments. Their regulation by UTP was confirmed by qPCR and ELISA experiments. We then evaluated the capacity of UTP-treated predifferentiated cADSC to increase post-ischemic revascularization in mice subjected to left anterior descending artery ligation. Predifferentiated cADSC treated or not with UTP were injected in the periphery of the infarcted zone, 3 days after ligation. We observed a significant increase of capillary density 14 and 30 days after UTP-treated predifferentiated cADSC injection, correlated with a reduction of cardiac fibrosis. This revascularization increase was not observed after injection of UTP-treated cADSC deficient for UTP and ATP nucleotide receptor P2Y2. The present study highlights the P2Y2 receptor as a regulator of cADSC endothelial differentiation and as a potential target for the therapeutic use of cADSC in post-ischemic heart revascularization.

Outcomes of pre-operative brachytherapy followed by hysterectomy for early cervical cancer.

OBJECTIVE: The standard of care for early cervical cancer is radical hysterectomy; however, consideration of pre-operative brachytherapy has been explored. We report our experience using pre-operative brachytherapy plus Wertheim-type hysterectomy to treat early stage cervical cancer. METHODS: This single-center study evaluated consecutive patients with histologically proven node-negative early stage cervical cancer (International Federation of Gynecology and Obstetrics 2009 stage IB1-IIB) that was treated using pre-operative brachytherapy and hysterectomy. Pre-brachytherapy staging was performed using magnetic resonance imaging (MRI) and pelvic lymph node assessment was performed using lymphadenectomy. The tumor and cervical tissues were treated using brachytherapy (total dose 60 Gy) followed by Wertheim-type hysterectomy. The study included patients from January 2000 to December 2013. RESULTS: A total of 80 patients completed a median follow-up of 6.7 years (range 5.4-8.5). The surgical specimens revealed a pathological complete response for 61 patients (76%). Patients with incomplete responses generally had less than 1 cm residual tumor at the cervix, and only one patient had lymphovascular space involvement. The estimated 5-year rates were 88% for overall survival (95% CI 78% to 94%) and 82% for disease-free survival (95% CI 71% to 89%). Toxicities were generally mild-to-moderate, including 26 cases (33%) of grade 2 late toxicity and 10 cases (13%) of grade 3 late toxicity. Univariate analyses revealed that poor disease-free survival was associated with overweight status (≥25 kg/m2, HR 3.05, 95% CI 1.20 to 7.76, p=0.019) and MRI tumor size >3 cm (HR 3.05, 95% CI 1.23 to 7.51, p=0.016). CONCLUSIONS: Pre-operative brachytherapy followed by Wertheim-type hysterectomy may be safe and effective for early stage cervical cancer, although poorer outcomes were associated with overweight status and MRI tumor size >3 cm.

Using the Patient Safety Huddle as a Tool for High Reliability.

A Patient Safety Huddle was developed at a community hospital (Providence Little Company of Mary Medical Center, San Pedro, California) through consultation with key stakeholders. The goal was to become a high reliability organization by improving communication across different departments, troubleshooting operational problems, focusing on safety and quality metrics, and reporting unusual occurrences. The Patient Safety Huddle involved executives in development and implementation, respect for employee time, ensuring accountability, and empowering frontline staff to foresee and deal with safety issues. The current template of the Patient Safety Huddle agenda and the Documentation Tools used to address patient safety issues are provided.

Loss of Mouse P2Y6 Nucleotide Receptor Is Associated with Physiological Macrocardia and Amplified Pathological Cardiac Hypertrophy.

The study of the mechanisms leading to cardiac hypertrophy is essential to better understand cardiac development and regeneration. Pathological conditions such as ischemia or pressure overload can induce a release of extracellular nucleotides within the heart. We recently investigated the potential role of nucleotide P2Y receptors in cardiac development. We showed that adult P2Y4-null mice displayed microcardia resulting from defective cardiac angiogenesis. Here we show that loss of another P2Y subtype called P2Y6, a UDP receptor, was associated with a macrocardia phenotype and amplified pathological cardiac hypertrophy. Cardiomyocyte proliferation and size were increased in vivo in hearts of P2Y6-null neonates, resulting in enhanced postnatal heart growth. We then observed that loss of P2Y6 receptor enhanced pathological cardiac hypertrophy induced after isoproterenol injection. We identified an inhibitory effect of UDP on in vitro isoproterenol-induced cardiomyocyte hyperplasia and hypertrophy. The present study identifies mouse P2Y6 receptor as a regulator of cardiac development and cardiomyocyte function. P2Y6 receptor could constitute a therapeutic target to regulate cardiac hypertrophy.

[Systemic EBV+ T-cell lymphoproliferative disease of childhood]. / Lymphoprolifération systémique T liée à l'EBV chez l'enfant.

Systemic EBV+ T-cell lymphoproliferative disease of childhood is a recent entity described in the 2008 World Health Organisation tumours of haematopoietic system and lymphoid tissues as a clonal T-cell EBV+ systemic proliferation. It occurs after acute or chronic active EBV infection. We report the case of a caucasian, immunocompetent 12-year-old girl, with no particular history, who presented with hemophagocytic lymphohistiocytosis in the aftermath of an infectious mononucleosis. Main symptoms were multiple organ failure, hepatosplenomegaly and pancytopenia. Histopathology of peripheral lymph node and bone marrow revealed a T-cell, CD8+, EBV+ lymphoproliferation. An elevated viral load was detected in blood by PCR. The patient died within 3 weeks. Since most of the cases have been reported in Asia and South America, few cases still have been described in Europe. Unlike B-cell lymphoproliferation in immunocompromised individuals, T-cell EBV+ lymphoproliferation occurs in immunocompetent patients and seems to be the consequence of a proliferative disorder of EBV-infected T-cells, attributed to a cytotoxic T-cell response deficiency. These T-cell proliferations are more frequently immunoreactive for CD8 than CD4. A key feature of the diagnosis might be EBV viral load.

Fallopian tube lesions as potential precursors of early ovarian cancer: a comprehensive proteomic analysis.

Ovarian cancer is the leading cause of death from gynecologic cancer worldwide. High-grade serous carcinoma (HGSC) is the most common and deadliest subtype of ovarian cancer. While the origin of ovarian tumors is still debated, it has been suggested that HGSC originates from cells in the fallopian tube epithelium (FTE), specifically the epithelial cells in the region of the tubal-peritoneal junction. Three main lesions, p53 signatures, STILs, and STICs, have been defined based on the immunohistochemistry (IHC) pattern of p53 and Ki67 markers and the architectural alterations of the cells, using the Sectioning and Extensively Examining the Fimbriated End Protocol. In this study, we performed an in-depth proteomic analysis of these pre-neoplastic epithelial lesions guided by mass spectrometry imaging and IHC. We evaluated specific markers related to each preneoplastic lesion. The study identified specific lesion markers, such as CAVIN1, Emilin2, and FBLN5. We also used SpiderMass technology to perform a lipidomic analysis and identified the specific presence of specific lipids signature including dietary Fatty acids precursors in lesions. Our study provides new insights into the molecular mechanisms underlying the progression of ovarian cancer and confirms the fimbria origin of HGSC.

Fetal and Neonatal Adverse Drug Reactions Associated with Biologics Taken During Pregnancy by Women with Autoimmune Diseases: Insights from an Analysis of the World Health Organization Pharmacovigilance Database (VigiBase®).

INTRODUCTION: Published data on the safety of biologics other than tumor necrosis factor (TNF) inhibitors during pregnancy are limited. OBJECTIVE: The aim was to detect pharmacovigilance signals for fetal and neonatal adverse drug reactions (ADRs) to biologics taken by pregnant women with autoimmune diseases. METHODS: We performed a disproportionality analysis of the World Health Organization's VigiBase® pharmacovigilance database from 1968 to June 1, 2021. Data were collected in June 2021. By using terms for different hierarchical levels of the Medical Dictionary for Regulatory Activities, we selected the following fetal or neonatal ADRs: stillbirth, premature birth, low birth weight, small for gestational age, and congenital malformations. The frequency of all identified ADRs for biologics of interest (adalimumab, infliximab, golimumab, certolizumab, etanercept, anakinra, canakinumab, tocilizumab, sarilumab, ustekinumab, guselkumab, secukinumab, ixekizumab, belimumab, abatacept, and rituximab) was compared with that of all other reports for all other drugs and quoted as the reporting odds ratio (ROR) [95% confidence interval]. Reports with known concomitant use of teratogenic drugs were excluded from the main analysis. Other analyses included ROR stratifications by therapeutic indication in the periods 1968-2021 and 2001-2021, and an analysis after excluding reports with steroids. RESULTS: In the main analysis, the RORs were particularly high for musculoskeletal malformations with anakinra (7.18 [3.50-14.73]), canakinumab (19.54 [12.82-29.79]), and abatacept (5.09 [2.77-9.33]), and for immune system disorders with canakinumab (347.88 [217.9-555.50]) and rituximab (9.27 [2.95-29.15]). After the exclusion of reports with steroids, the ROR was significant for neonatal infections with belimumab (28.49 [5.75-141.25]). CONCLUSION: We identified possible associations with some adverse fetal and neonatal outcomes, suggesting that vigilance is required when prescribing certain biologics during pregnancy.

Prophylactic Radical Fimbriectomy with Delayed Oophorectomy in Women with a High Risk of Developing an Ovarian Carcinoma: Results of a Prospective National Pilot Study.

Risk-reducing salpingo-oophorectomy is the gold standard for the prophylaxis of ovarian cancer in high-risk women. Due to significant adverse effects, 20-30% of women delay or refuse early oophorectomy. This prospective pilot study (NCT01608074) aimed to assess the efficacy of radical fimbriectomy followed by a delayed oophorectomy in preventing ovarian and pelvic invasive cancer (the primary endpoint) and to evaluate the safety of both procedures. The key eligibility criteria were pre-menopausal women ≥35 years with a high risk of ovarian cancer who refused a risk-reducing salpingo-oophorectomy. All the surgical specimens were subjected to the SEE-FIM protocol. From January 2012 to October 2014, 121 patients underwent RF, with 51 in an ambulatory setting. Occult neoplasia was found in two cases, with one tubal high-grade serous ovarian carcinoma. Two patients experienced grade 1 intraoperative complications. No early or delayed grade ≥3 post-operative complications occurred. After 7.3 years of median follow-up, no cases of pelvic invasive cancer have been noted. Three of the fifty-two patients developed de novo breast cancer. One BRCA1-mutated woman delivered twins safely. Twenty-five patients underwent menopause, including fifteen who had received chemotherapy for breast cancer, and twenty-three underwent menopause before the delayed oophorectomy, while two did not undergo a delayed oophorectomy at all. Overall, 46 women underwent a delayed oophorectomy. No abnormalities were found in any delayed oophorectomy specimens. Radical fimbriectomy followed by delayed oophorectomy appears to be a safe and well-tolerated risk-reducing approach, which avoids early menopause for patients with a high risk of breast and ovarian cancer.

Assessment of 19 years of a prospective national survey on drug-facilitated crimes in France.

Drug facilitated-crime or chemical submission (DFC/CS) is defined as the concealed or forced administration of psychoactive substances to a victim for criminal purposes. This is a national program set up in the early 2000 s in the form of a prospective multicenter survey, the results of which this manuscript presents. Over this 19-year period, 5487 cases were collected, analyzed and classified into 54 % of suspected cases, 29 % of chemical vulnerability (CV) cases and 17 % of proven DFC/CS cases. In the overall data, the most prevalent victims were female (81 %), with an average age of 27 years. Sexual assault was the most frequent aggression (77 %), followed by theft (14 %). Victims of proven DFC/CS cases were from of all ages including children and elderly. In 934 victims of DFC/CS, 100 various psychoactive substances were detected mostly represented by benzodiazepines and z-drugs (55 %), various sedatives including antihistamines (16 %) and non-therapeutic substances (16 %). Gamma-hydroxybutyric acid (GHB) was found in 4 % cases. In CV cases, alcohol (90 %) and cannabis (32 %) intake were mainly involved. In France, despite prevention messages, DFC/CS has been an epidemic for many years and has been proven by our national study. This national program has the aim to identifying the substances used but unfortunately not the goal to fight against this phenomenon. Since 2009, we observed a new modus operandi of the aggressors who pose as taxi drivers facilitating the reception of the victims leaving nightclubs. We can emphasize that GHB is not the "date rape drug" but rather the benzodiazepine class is.

A New Paradigm in Managing Advanced Ovarian Cancer: Differentiating Patients Requiring Neoadjuvant Treatment from Primary Cytoreduction.

Our study aims to evaluate the comparability of primary debulking surgery (PDS) and neoadjuvant chemotherapy (NACT) patients. This single-center retrospective study includes all patients treated for advanced stages high-grade serous ovarian carcinomas (HGSOC) between 2007 and 2017. Preoperative characteristics and postoperative outcomes were compared after a propensity score matching analysis. Of the 221 patients included, 38% underwent PDS, and 62% received NACT. There was no age difference at diagnosis; however, CA125 levels, PCI score levels, and rates of stage IV were higher in the NACT group. There were no differences concerning the rate and the severity of complications (p = 0.29). The propensity score distribution showed a broad distinction between PDS patients and NACT patients with no significant overlap. Survival analyses demonstrate, after a median follow-up of 66.5 months, an overall survival (OS) of 105.9 and progression-free survival (PFS) of 29.2 months in the PDS group, compared to OS of 52.8 and PFS of 18.9 months in the NACT group. Advanced HGSOC is a heterogeneous population, in which inoperable patients should be differentiated from PDS patients based on many factors, primarily tumor burden.

In-depth proteomics analysis of sentinel lymph nodes from individuals with endometrial cancer.

Endometrial cancer (EC) is one of the most common gynecological cancers worldwide. Sentinel lymph node (SLN) status could be a major prognostic factor in evaluation of EC, but several prospective studies need to be performed. Here we report an in-depth proteomics analysis showing significant variations in the SLN protein landscape in EC. We show that SLNs are correlated to each tumor grade, which strengthens evidence of SLN involvement in EC. A few proteins are overexpressed specifically at each EC tumor grade and in the corresponding SLN. These proteins, which are significantly variable in both locations, should be considered potential markers of overall survival. Five major proteins for EC and SLN (PRSS3, PTX3, ASS1, ALDH2, and ANXA1) were identified in large-scale proteomics and validated by immunohistochemistry. This study improves stratification and diagnosis of individuals with EC as a result of proteomics profiling of SLNs.

Characteristics and Clinical Value of 18F-FDG PET/CT in the Management of Adult-Onset Still's Disease: 35 Cases.

While the diagnosis of adult-onset Still's disease (AOSD) involves the exclusion of differential diagnoses, the characteristics and value of 18F-Fluorodeoxyglucose (18F-FDG) Positron Emission Tomography coupled with CT (PET/CT) in the management of AOSD remain poorly known. Our retrospective study included patients from four centers, fulfilling Yamaguchi or Fautrel criteria, who underwent a PET/CT during an active AOSD. Thirty-five patients were included. At the time of PET/CT, the Yamaguchi criteria were met in 23 of 29 evaluable cases. PET/CT showed bone marrow (74.3%), lymph node (74.3%), and splenic (48.6%) FDG uptake. Despite arthralgia or arthritis in most patients, joints were rarely the sites of 18F-FDG accumulation. The spatial distribution of 18F-FDG uptake was nonspecific, and its intensity could be similar to malignant disease. Lymph node or bone marrow biopsy was performed after PET/CT in 20 patients (57.1%). The intensity of bone marrow; splenic and lymph node hypermetabolism appeared to be correlated with disease activity. Abnormal PET/CT in the cervical lymph nodes and age ≥ 60 years seemed to be predictive factors for monocyclic evolution. The clinical value of PET/CT is not in direct diagnosis; but as an aid in excluding differential diagnoses by searching for their scintigraphic features and guiding biopsy.

Associations between osteoporosis and drug exposure: A post-marketing study of the World Health Organization pharmacovigilance database (VigiBase®).

BACKGROUND: Bone remodeling is a complex process, and many conditions (including drug exposure) lead to osteoporosis. Here, we sought to detect new disproportionality signals for drugs associated with osteoporosis. METHODS: We performed a disproportionality analysis of the World Health Organization's VigiBase® pharmacovigilance database through April 12, 2020. The frequency of reports on osteoporosis for all identified drug classes was compared with that for all other drugs and quoted as the reporting odds ratio (ROR) [95% confidence interval (CI)]. RESULTS: Of the 7,594,968 cases spontaneously recorded to VigiBase®, 4758 concerned osteoporosis. New disproportionality signals with a pharmacologically plausible mechanism were found for drugs used in neurology (levodopa (ROR [95%CI]: 10.18 [4.33-25.10]), selective serotonin agonists (4.22 [2.34-7.00]) and memantine (4.10 [1.56-8.93])), hematology (romiplostim (4.93 [1.15-21.10])), pulmonology (macitentan (3.02 [1.84-4.90])), ophthalmology (ranibizumab (3.31 [1.00-10.51])) and rheumatology (tofacitinib (3.65 [3.00-4.40])). The robustness of these new results is supported by the significant RORs for the vast majority of drugs already known to induce osteoporosis and/or increase the fracture risk, namely glucocorticoids, gonadotropin-releasing hormone analogs, anti-aromatases, androgen receptor blockers, thyroid hormones, proton pump inhibitors, thiazolidinediones, vitamin K antagonists, loop diuretics, protease inhibitors, nucleoside and nucleotide reverse transcriptase inhibitors, and enzyme-inducing antiepileptics including barbiturates and derivatives, hydantoin derivatives, carboxamide derivatives and fatty acid derivatives. CONCLUSION: We established up a comprehensive list of drugs potentially associated with osteoporosis and highlighted those with pharmacologically plausible mechanisms leading to bone fragility. Our results might pave the way for additional exploration of these mechanisms.

Strontium ranelate decreases receptor activator of nuclear factor-ΚB ligand-induced osteoclastic differentiation in vitro: involvement of the calcium-sensing receptor.

Strontium ranelate exerts both an anticatabolic and an anabolic effect on bone cells. To further investigate the mechanism by which strontium ranelate inhibits bone resorption, the effects of varying concentrations of Sr(o)(2+) on osteoclastic differentiation were studied using RAW 264.7 cells and peripheral blood monocytic cells (PBMCs). We report that increasing concentrations of Sr(o)(2+) down-regulate osteoclastic differentiation and tartrate-resistant acid phosphatase activity, leading to inhibition of bone resorption (-48% when PBMCs were cultured for 14 days in the presence of 2 mM Sr(o)(2+)). Using a dominant-negative form of the calcium-sensing receptor (CaR) and a small interfering RNA approach, we provide evidences that the inhibition of osteoclast differentiation by Sr(o)(2+) is mediated by stimulation of the CaR. Moreover, our results suggest that the effects of Sr(o)(2+) on osteoclasts are, at least in part, mediated by inhibition of the receptor activator of nuclear factor-κB ligand (RANKL)-induced nuclear translocation of nuclear factor-κB and activator protein-1 in the early stages of osteoclastic differentiation. In conclusion, our data indicate that Sr(2+) directly inhibits the formation of mature osteoclasts through down-regulation of RANKL-induced osteoclast differentiation and decreases osteoclast differentiation through the activation of the CaR.

Relapses in patients with anti-neutrophil cytoplasmic antibody-associated vasculitis: a retrospective study.

OBJECTIVE: To investigate the activity of relapsing events (RE) and their mode of presentation in patients with anti-neutrophil cytoplasmic (ANCA)-associated vasculitis (AAV). METHODS: Patients diagnosed with AAV between 1990 and 2015 experiencing at least one RE were investigated. The different organ involvements were registered during each RE. Presentation at initial onset (IO) and RE were compared. The Birmingham Vasculitis Activity Score was used to assess the activity. RESULTS: Ninety-nine patients were followed: 54 patients with 96 RE and 45 patients with none. The rate of RE was 53% with a median time of follow-up of 6.8 years. The mean time to first RE was 2.8 years. Thirty patients experienced one single RE, 15 had 2, 5 had 3, 2 had 4, and 2 had, respectively, 7 and 8. Fifty-five percent of RE had the same features as IO. Compared to IO, some clinical manifestations were less present: constitutional symptoms (29% vs 69%), ear-nose-throat (50% vs 76%), lung involvement (59% vs 76%), peripheral neuropathies (14% vs 24%), arthritis (7% vs 27%), kidney (25% vs 41%), and heart (4% vs 20%) (p < 0.001). Skin, eye, and bowel manifestations were not significantly less involved during RE. The mean Birmingham Vasculitis Activity Score at IO was 9.02 and 5.11 at relapse (p < 0.0001). Among the 96 RE, 46% had a new organ involvement compared to IO: none were life-threatening. CONCLUSION: Global activity of RE in AAV patients is lower than that of IO. Fewer organs are involved in relapses. RE turned out to begin with the same manifestations as IO in most cases.Key Points•First study looking into clinical characteristics of relapses including mostly granulomatosis with polyangiitis.•Around half of patients with AAV seemed to relapse in a similar way compared to the initial diagnosis.•The activity score during relapsing events is less important.

Association between Uremic Toxin Concentrations and Bone Mineral Density after Kidney Transplantation.

Although uremic osteoporosis is a component of mineral and bone disorder in chronic kidney disease, uremic toxin (UT) concentrations in patients with end-stage kidney disease and bone mineral density (BMD) changes after kidney transplantation have not previously been described. We hypothesized that elevated UT concentrations at the time of transplantation could have a negative impact on bone during the early post-transplantation period. Hence, we sought to determine whether concentrations of UTs (trimethylamine-N-oxide, indoxylsulfate, p-cresylsulfate, p-cresylglucuronide, indole-3-acetic acid, hippuric acid, and 3-carboxy-4-methyl-5-propyl-furanpropionic acid) upon transplantation are predictive markers for (i) osteoporosis one month after transplantation, and (ii) a BMD decrease and the occurrence of fractures 12 and 24 months after kidney transplantation. Between 2012 and 2018, 310 kidney transplant recipients were included, and dual-energy X-ray absorptiometry was performed 1, 12, and 24 months after transplantation. The UT concentrations upon transplantation were determined by reverse-phase high-performance liquid chromatography. Indoxylsulfate concentrations upon transplantation were positively correlated with BMD one month after transplantation for the femoral neck but were not associated with osteoporosis status upon transplantation. Concentrations of the other UTs upon transplantation were not associated with osteoporosis or BMD one month after transplantation. None of the UT concentrations were associated with BMD changes and the occurrence of osteoporotic fractures 12 and 24 months after transplantation. Hence, UT concentrations at the time of kidney transplantation were not predictive markers of osteoporosis or fractures.

Metformin Treatment in Patients With Type 2 Diabetes and Chronic Kidney Disease Stages 3A, 3B, or 4.

OBJECTIVE: This study was conducted to define a safe, effective dose regimen for metformin in moderate and severe chronic kidney disease (CKD; stages 3A/3B and 4, respectively), after the lifting of restrictions on metformin use in patients with diabetes with moderate-to-severe CKD in the absence of prospective safety and efficacy studies. RESEARCH DESIGN AND METHODS: Three complementary studies were performed: 1) a dose-finding study in CKD stages 1-5, in which blood metformin concentrations were evaluated during a 1-week period after each dose increase; 2) a 4-month metformin treatment study for validating the optimal metformin dose as a function of the CKD stage (3A, 3B, and 4), with blood metformin, lactate, and HbA1c concentrations monitored monthly; and 3) an assessment of pharmacokinetic parameters after the administration of a single dose of metformin in steady-state CKD stages 3A, 3B, and 4. RESULTS: First, in the dose-finding study, the appropriate daily dosing schedules were 1,500 mg (0.5 g in the morning [qam] +1 g in the evening [qpm]) in CKD stage 3A, 1,000 mg (0.5 g qam + 0.5 g qpm) in CKD stage 3B, and 500 mg (qam) in CKD stage 4. Second, after 4 months on these regimens, patients displayed stable metformin concentrations that never exceeded the generally accepted safe upper limit of 5.0 mg/L. Hyperlactatemia (>5 mmol/L) was absent (except in a patient with myocardial infarction), and HbA1c levels did not change. Third, there were no significant differences in pharmacokinetic parameters among the CKD stage groups. CONCLUSIONS: Provided that the dose is adjusted for renal function, metformin treatment appears to be safe and still pharmacologically efficacious in moderate-to-severe CKD.