Efficacy of bi-level erector spinae plane block versus bi-level thoracic paravertebral block for postoperative analgesia in modified radical mastectomy: a prospective randomized comparative study.

BACKGROUND: Postoperative analgesia in breast surgery is difficult due to the extensive nature of the surgery and the complex innervation of the breast; general anesthesia can be associated with regional anesthesia techniques to control intra- and post-postoperative pain. This randomized comparative study aimed to compare the efficacy of the erector spinae plane block and the thoracic paravertebral block in radical mastectomy procedures with or without axillary emptying. METHODS: This prospective randomized comparative study included 82 adult females who were randomly divided into two groups using a computer-generated random number. Both groups, Thoracic Paraverterbal block group and Erector Spinae Plane Block group (41 patients each), received general anesthesia associated with a multilevel single-shot thoracic paravertebral block and a multilevel single-shot erector spinae plane block, respectively. Postoperative pain intensity (expressed as Numeric Rating Scale), patients who needed rescue analgesic, intra- and post-operative opioid consumption, post-operative nausea and vomiting, length of stay, adverse events, chronic pain at 6 months, and the patient's satisfaction were recorded. RESULTS: At 2 h (p < 0.001) and 6 h (p = 0.012) the Numeric Rating Scale was significantly lower in Thoracic Paraverterbal block group. The Numeric Rating Scale at 12, 24, and 36 postoperative hours did not show significant differences. There were no significant differences also in the number of patients requiring rescue doses of NSAIDs, in intra- and post-operative opioid consumption, in post-operative nausea and vomiting episodes and in the length of stay. No failures or complications occurred in the execution of techniques and none of the patients reported any chronic pain at six months from the surgery. CONCLUSIONS: Both thoracic paravertebral block and erector spinae plane block can be effectively used in controlling post-mastectomy pain with no significant differences between the two blocks. TRIAL REGISTRATION: The study was prospectively registered on Clinicaltrials.gov (trial identifier NCT04457115) (first registration 27/04/2020).

Early initiation of cinacalcet for the treatment of secondary hyperparathyroidism in hemodialysis patients: a three-year clinical experience.

Despite the availability of standard therapy (vitamin D sterols and phosphate binders) for the treatment of secondary hyperparathyroidism (SHPT) in hemodialyzed (HD) patients, a significant percentage of patients still fail to achieve targets recommended by the Kidney Disease Outcomes Quality Initiative (K/DOQI) of the National Kidney Foundation for parathyroid hormone (PTH), calcium, and phosphorus. The calcimimetic cinacalcet (CN) has been shown to be an effective treatment for SHPT, significantly reducing serum PTH while simultaneously lowering calcium, phosphorus, and calcium-phosphorus product levels, thus increasing the proportion of patients achieving the K/DOQI targets for bone mineral parameters. The aim of this study was to evaluate if early treatment with CN had beneficial effects in HD patients with mild-to-moderate SHPT in whom conventional treatments had failed to achieve NKF-K/DOQI targets for PTH, serum-corrected calcium, and phosphorus while minimizing the risk of paradoxical hypercalcemia and/or hyperphosphatemia. Clinical practice data were collected monthly, starting from 6 months prior to, and up to 36 months after, the start of CN therapy. CN was started at a dose of 30 mg daily or every other day, and titrated thereafter to achieve intact PTH (iPTH) <300 pg/mL. The dose of concomitant vitamin D and phosphate binders were also adjusted in order to achieve K/DOQI targets. Data from 32 patients were collected, 28 of whom had been treated with CN for at least 36 months at the time of data analysis. At baseline, patients had serum iPTH >300 pg/mL (570 ± 295 pg/mL) and/or serum-corrected calcium >9.5 mg/dL. CN induced significant decreases in iPTH, calcium, and calcium-phosphorus product with respect to baseline levels. The percentage of patients within K/DOQI target levels at baseline, 12, 24, and 36 months was 0, 81.2, 83.3, and 86.2% for iPTH; 34.4, 65.6, 86.6, and 89.6% for serum-corrected calcium; 40.6, 56.2, 69.6, and 72.4% for phosphorus; and 37.5, 62.5, 80, and 82.7% for calcium-phosphorus product. The mean dose of CN at the end of the observation period was 38 mg/day. The mean dose of concomitant medication (calcitriol, Al-containing phosphate binders, and sevelamer) decreased from baseline to 36 months. Early treatment with CN in HD patients with SHPT increases the proportion of patients achieving and maintaining K/DOQI targets with a low dose of CN (38 mg/day). These results suggest that the metabolic control obtained with low-dose CN administered early in the course of SHPT can be maintained or increased over time.

Erratum: SARS-CoV-2 infection in dialysis patients in northern Italy: a single-centre experience.

[This corrects the article DOI: 10.1093/ckj/sfaa084.][This corrects the article DOI: 10.1093/ckj/sfaa084.].

A possible future for anaesthesia in breast surgery: thoracic paravertebral block and awake surgery. A prospective observational study.

INTRODUCTION: Quadrantectomy is a surgical procedure traditionally performed under general anaesthesia with intraoperative and postoperative opioid-based analgesia. The use of locoregional anaesthesia techniques in breast surgery has become widespread and allows excellent management of intraoperative and postoperative pain with reduced opioid consumption. We chose thoracic paravertebral block as regional anaesthesia technique in breast surgery to investigate the possibility of carrying out this surgery with the patient awake. METHODS: A prospective observational study on 50 patients was designed. The primary outcome for this study was the possibility to carry out the surgery with only the paravertebral block associated with mild sedation without general anaesthesia. Forty minutes before the start of the surgery, an ultrasound-guided thoracic paravertebral block was performed at two thoracic levels, and for each level, 7 mL of ropivacaine 0.7% was injected. Sedation was obtained with target-controlled infusion of propofol. RESULTS: Forty-nine patients underwent the operation awake; in one case, we had to place an I-gel and perform general anaesthesia. No patient needed intraoperative or postoperative opioids. The numeric rating scale, recorded at 0, 2, 6, 12, 24, and 36 hours, was greater than 3 in only five patients. CONCLUSIONS: We believe that if in the future we try to make quadrantectomy an intervention in which the anaesthesia is exclusively regional, therefore with a patient awake and collaborating, it will not be possible to ignore the use of thoracic paravertebral block.

Phase II study of liposomal doxorubicin, docetaxel and trastuzumab in combination with metformin as neoadjuvant therapy for HER2-positive breast cancer.

BACKGROUND: The aim of this study was to improve activity over single human epidermal growth factor receptor 2 (HER2)-blockade sequential neaodjuvant regimens for HER2-positive breast cancer, by exploiting the concomitant administration of trastuzumab, taxane and anthracycline, while restraining cardiac toxicity with use of liposomal doxorubicin, and by adding metformin, based on preliminary evidence of antitumor activity. PATIENTS AND METHODS: This multi-center, single-arm, two-stage phase II trial, assessed the safety and the activity of a new treatment regimen for HER2-positive, early or locally advanced breast cancer. Patients received six 21-day cycles of non-pegylated liposomal doxorubicin, 50 mg/m2 intravenously (i.v.) on day 1, docetaxel, 30 mg/m2 i.v. on days 2 and 9, trastuzumab, 2 mg/kg/week i.v. on days 2, 9, and 16 (with 4 mg/kg loading dose), in association with metformin 1000 mg orally twice daily. The primary endpoint was the rate of pathological complete response (pCR) in the breast and axilla (ypT0/is ypN0). A subgroup of patients performed a 3-deoxy-3-18F-fluorothymidine positron emission tomography (FLT-PET) at baseline and after one cycle. RESULTS: Among 47 evaluable patients, there were 18 pCR [38.3%, 95% confidence interval (CI) 24.5-53.6%]. A negative estrogen-receptor status, high Ki67, and histological grade 3 were related with pCR, although only grade reached statistical significance. FLT-PET maximum standardized uptake value after one cycle was inversely related to pCR in the breast (odds ratio 0.29, 95% CI 0.06-1.30, p = 0.11). Toxicity included grade 3-4 neutropenia in 70% and febrile neutropenia in 4% of patients, grade 1-2 nausea/vomiting in 60%/38%, and grade 3 in 4%/2%, respectively, grade 1-2 diarrhea in 72%, and grade 3 in 6%. There were two cases of reversible grade 2 left-ventricular ejection-fraction decrease, and one case of sharp troponin-T increase. CONCLUSIONS: The concomitant administration of trastuzumab, liposomal doxorubicin, docetaxel, and metformin is safe and shows good activity, but does not appear to improve activity over conventional sequential regimens.

SARS-CoV-2 infection in dialysis patients in northern Italy: a single-centre experience.

BACKGROUND: Dialysis patients are considered at high risk for COVID-19 and the infection can easily spread in dialysis units. METHODS: We conducted an observational single-centre cohort study to describe clinical characteristics, treatments and outcomes of dialysis patients with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection. We tested patients who presented symptoms or had contact with a confirmed case. We enrolled 15 patients positive for SARS-CoV-2. RESULTS: We tested 37 of 306 dialysis patients. Patients with SARS-CoV-2 infection were older (mean age 75.96 ± 11.09 years) and all had comorbidities. At presentation, most had interstitial infiltrates on chest X-ray, three-quarters had leucopenia and none had respiratory insufficiency. During follow-up, there was an increase in serum C-reactive protein and interleukin-6. Eighty percent of patients received supplemental oxygen; none received non-invasive ventilation, one was intubated. Most patients (80%) were treated with oral hydroxychloroquine for a median time of 6.5 days [interquartile range (IQR) 5-14.5] and 40% received azithromycin; two patients received a short course of antivirals and one received a single dose of tocilizumab. Only two patients did not require hospitalization. Of the nine survivors, eight still tested positive for SARS-CoV-2 a median of 19 days (IQR 9.25-23) after diagnosis. Six patients died (case fatality rate 40%) a median of 5.5 days (IQR 1.75-9.75) after diagnosis. The main reported cause of death was respiratory failure related to COVID-19 (five patients). CONCLUSIONS: We report a single-centre experience of SARS-CoV-2 infection in dialysis patients. The disease showed a high case fatality rate and most patients required hospitalization. Survivors show prolonged viral shedding.

Long-term effects of COVID-19 in a patient on maintenance dialysis.

Coronavirus infectious disease (COVID-19) is a novel respiratory infection highly associated with severe complications in elderly subjects affected by cardiovascular disease. Patients on maintenance dialysis are exceptionally vulnerable because most of them are old and have multiple comorbidities. We report the complex clinical course of SARS-CoV-2 infection in a patient on maintenance dialysis who presented with fever and lung edema. After 41 days from the primary infection, the clinically recovered patient experienced symptomatic reactivation of SARS-COV-2 infection documented by positive polymerase chain reaction (PCR) result on nasal/oropharyngeal swab along with immunoglobulin M seroconversion. The recurrence of PCR positivity forced us to perform hemodialysis in a separate isolation room for a prolonged period of time. Close monitoring of previously infected patients and restructuring of dialysis facilities are necessary to avoid new outbreaks of this concerning disease.

Single shot ultrasound-guided thoracic paravertebral block for opioid-free radical mastectomy: a prospective observational study.

BACKGROUND: General anesthesia (GA) is the most commonly used anesthesiological technique for radical mastectomy operations and can be associated with loco-regional anesthesia techniques. The aim of our study, carried out on 51 patients, was to assess the effectiveness of thoracic paravertebral block (TPVB) associated with GA, or as a sole anesthesiological technique for postoperative pain control and for the reduction of intra and postoperative opioids consumption. MATERIALS AND METHODS: Fifty-one patients with neoplastic breast disease and elected as candidates for radical mastectomy were included in the study. The primary outcomes for this study were intra and postoperative opioid consumption and postoperative pain intensity. In 37 patients, TPVB was associated with GA while in 14 patients it was used as the sole anesthesiological technique. Data are reported as mean with standard deviation median with interquartile range, number, and percentage, depending on the underlying distribution. RESULTS: We did not use intra or postoperative opioids for any patient and the Numeric Rate Scale, assessed at time 0, at the end of the surgery, and 2, 6, 12, and 24 hrs after surgery, was >3 in seven patients only. CONCLUSIONS: This study aims to show how TPVB can be used to carry out radical mastectomy procedures so that intra and postoperative opioids use can be avoided. In our study, TPVB was used in total mastectomy procedures in association with GA or as the sole anesthesiological technique, without the intra and postoperative use of opioids and with a significant reduction of local anesthetic dosages compared to those reported in the existing literature.

A validated model of disease progression in IgA nephropathy.

BACKGROUND: IgA nephropathy (IgAN) is the most common primary glomerulonephritis in the general population. There is accumulating evidence that immunosuppressive treatment is efficacious in IgAN. However, it is critical to define appropriate indicators for this therapy especially in the wake of potentially deleterious side effects to immunosuppressives. METHODS: This study retrospectively reviewed IgAN cases collected since 1981 to identify clinical and/or histological parameters for disease progression; 310 patients with biopsy proven IgAN, diagnosed from January 1981 to March 2004, were included. RESULTS: We defined a clinical prognostic index (CPI) using multivariate analysis, which incorporated these clinical/ histological parameters. Semiquantitative scores were assigned as follows: 2 points if creatinine (Cr) was >1.4 mg/dL, 1 point if proteinuria was >1 g/24 hr, 1 point if a patient was affected by hypertension, and 1 point if a patient was older than 30 yrs. Dividing our population into two groups (scores 0-2 = low CPI group; scores 3-5 = high CPI group), we demonstrated a significantly different 10-yr renal survival rate; in the low CPI group, renal survival since time of biopsy at 10 yrs was 91.7%; in the high CPI group the renal survival at 10 yrs was 35%. We validated the CPI in an independent sample from Verona (validation group) and demonstrated similar results for the CPI. CONCLUSIONS: The CPI is convenient to use for defining the risk of disease progression.

The role of blood volume reduction in the genesis of intradialytic hypotension.

BACKGROUND: The aim of this multicenter prospective study was to investigate the role of relative blood volume (RBV) reduction on intradialytic hypotension. METHODS: One hundred twenty-three patients on chronic hemodialysis therapy were considered a priori normotensive (reference group A), intradialytic hypotension prone (group B), and hypertensive (group C). RBV was continuously monitored, and diastolic and systolic blood pressure (SBP) and heart rate (HR) were measured at 20-minute intervals during three dialysis sessions. RESULTS: Intradialytic RBV reduction was -13.8% +/- 7.0% and similar in the three groups (P = 0.841). SBP and RBV decreased during dialysis, with a sharp initial decrease (in the first 20 minutes for SBP and the first 40 minutes for RBV), followed by a slower decrease. The lying bradycardic response before dialysis was less in group B than group A (a decrease of 3 +/- 7 versus 9 +/- 9 beats/min; P < 0.001). When symptomatic hypotension occurred, RBV reduction was not significantly different from that recorded at the same time during hypotension-free sessions (-13.9% +/- 6.4% versus -12.7% +/- 5.2%; P = 0.149). Group, baseline plasma-dialysate sodium gradient, RBV line irregularity, and early RBV and HR reduction during dialysis influenced the relative risk for symptomatic hypotension with a sensitivity of 80% versus 30% for RBV alone. CONCLUSION: We found no difference in reduction in RBV in the three groups and no critical RBV level for the appearance of symptomatic hypotension. With variables easily available within 40 minutes of dialysis, RBV monitoring increases the prediction of symptomatic hypotension.

Gefitinib and afatinib treatment in an advanced non-small cell lung cancer (NSCLC) patient undergoing hemodialysis.

Renal failure in cancer patients is not a rare clinical condition and often contraindicates anticancer drug treatment; moreover, chemotherapeutic drugs are frequently identified as possible iatrogenic cause of renal failure. Molecular therapies, when appropriate, could represent a therapeutic option for cancer patients with severe renal disease, but the lack of knowledge in this field, at present, limits their use in patients undergoing dialysis. Herein we describe a case, at our knowledge the first reported, of a patient with advanced lung adenocarcinoma on maintenance hemodialysis treated with gefitinib and then with afatinib; we also reviewed the literature on epidermal growth factor receptor (EGFR) tyrosine-kinase inhibitors (TKIs) used in NSCLC patients with concomitant renal impairment.

Proteomic analysis of early urinary biomarkers of renal changes in type 2 diabetic patients.

Diabetic nephropathy (DN) is a complication associated with diabetes, leading to end-stage renal disease (ESRD). Despite significant progress in understanding DN, the cellular mechanisms leading to the renal damage are incompletely defined. In this study, with the aim to identify urine biomarkers for the early renal alterations in type 2 diabetes mellitus (T2D), we performed urinary proteomic analysis of 10 normoalbuminuric patients with T2D, 12 patients with type 2 DN (T2DN), and 12 healthy subjects. Proteins were separated by 2-DE and identified with ESI-Q-TOF MS/MS. Comparing the patients proteomic profiles with those of normal subjects, we identified 11 gradually differently changed proteins. The decreased proteins were the prostatic acid phosphatase precursor, the ribonuclease and the kallikrein-3. Eight proteins were progressively increased in both patients groups: transthyretin precursor, Ig κ chain C region, Ig κ chain V-II region Cum, Ig κ-chain V-III region SIE, carbonic anhydrase 1, plasma retinol-binding protein, ß-2-microglobulin precursor, ß-2-glycoprotein 1. The proteomic analysis allowed us to identify several increased urinary proteins, not only in T2DN but also in T2D patients in which the microalbuminuria was in the normal range. These patterns of urinary proteins might represent a potential tool for a better understanding of diabetic renal damage.

Activation of coagulation during hemodialysis: effect of blood lines alone and whole extracorporeal circuit.

Activation of coagulation during hemodialysis (HD) is a relevant clinical problem, especially when patients at risk of bleeding are treated. However, little is known about the relative contribution of the various components of the circuit to the thrombotic process. Thus, an experimental model was developed that is aimed at evaluating biochemical markers of coagulation activation at different times and sites throughout the HD circuit. A HD blood-tubing set with integrated arterial and venous chambers (cartridge-line set) was used, which was added with the following sampling points: at the beginning of the arterial line (P1), before the blood pump (P2), after the blood pump (P3), and at the end of the venous line (P4). A bypass system allowed us to circulate the blood only into the blood lines for the first 20 min of the extracorporeal circulation. The extracorporeal circuit was rinsed with 1.7 L of heparinized saline (2,500 IU/L) that was completely discarded before patient connection. A continuous administration of unfractionated heparin (500-800 IU/h) without a starting bolus was adopted as a low heparin extracorporeal treatment. Samples were collected before the start of the extracorporeal circulation from the fistula needle (T0P0), after 5 (T1), 10 (T2), and 20 min (T3) from P1, P2, P3, and P4. After 20 min, the blood was returned to the patient using only saline and HD was then started, circulating the blood through the dialyzer. Further samples were obtained from P1 and P4 after 5 (T4) and 210 min (T5). Plasma levels of coagulation activation markers-thrombin-antithrombin complex (TAT) and prothrombin fragment 1 + 2 (F1 + 2)-were evaluated in all the samples in 12 stable HD patients. In each patient, the activated partial thromboplastin time (APTT) was measured at T0P0 and T1-T5 from P1. No significant changes were found at any time as far as F1 + 2 is concerned. However, TAT levels increased over time only after the start of HD, suggesting that the latter test could be more useful in order to detect coagulation activation during HD. The same experiments performed with nonheparin-primed extracorporeal circuit showed similar results. The blood lines used did not significantly activate coagulation during the first 20 min, whereas only 5 min of blood circulation throughout the whole circuit increased TAT values, which still remained lower than previous reports, even after 210 min of treatment.

Erythrocyte susceptibility to oxidative stress in chronic renal failure patients under different substitutive treatments.

An increased oxidative stress is now considered one of the major risk factors in chronic renal failure (CRF) patients that may be exacerbated by dialysis. It has been postulated that this increased oxidative stress might cause an augmented red blood cell (RBC) membrane lipid peroxidation with the consequent alteration in membrane deformability. The aim of this study was to evaluate RBC susceptibility to an in vitro induced oxidative stress and RBC antioxidant potential in different groups of CRF patients undergoing different substitutive treatment modalities. Fifteen end-stage CRF patients were evaluated in conservative treatment, 23 hemodialysis (HD) patients, 15 continuous ambulatory peritoneal dialysis (CAPD) patients, 15 kidney transplanted patients, and 16 controls. Their RBCs were incubated with the oxidative stress-inducing agent tert-butylhydroperoxide both in the presence and in the absence of the catalase inhibitor sodium azide, and the level of malondialdehyde (MDA) (a product of lipid peroxidation), was measured at 0, 5, 10, 15, and 30 min of incubation. In addition, the RBC content of reduced glutathione (GSH) was measured by HPLC. As opposed to the controls, RBCs from end-stage CRF patients exhibited an increased sensitivity to oxidative stress induced in vitro, both in the absence and presence of a catalase inhibitor, as demonstrated by a significantly higher level of MDA production at all the incubation times (P < 0.05). Different substitutive treatments had different impacts on this phenomenon; CAPD and kidney transplantation were able to normalize this alteration while HD was not. GSH appeared to be related to the increase in RBC susceptibility to oxidative stress; its content being significantly elevated in end-stage CRF and HD patients as compared with CAPD and transplanted patients and controls (P < 0.05). No significant changes were observed in the RBC glutathione content during the HD session. The increase of GSH in RBCs of end-stage CRF and HD patients seems to indicate the existence of an adaptive mechanism under increased oxidative stress occurring in vivo. Unlike HD, the beneficial effect of CAPD on the anemia of dialysis patients might partly be due to a condition of lower oxidative stress that might in addition counterbalance the cardiovascular negative effects of dislipidemia of CAPD patients.

Comparison between hydroperoxides and malondialdehyde as markers of acute oxidative injury during hemodialysis.

An increased free-radical production has been documented during hemodialysis (HD) particularly when bio-incompatible membranes are utilized. These highly reactive free radicals can cause damage through several pathways, one of the best known being lipid peroxidation. Malondialdehyde (MDA) is a product of lipid peroxidation, which can partly be removed by HD due to its low molecular weight and water solubility. Hydroperoxides are predominantly found in lipid substances, and therefore their removal by HD could be difficult. We evaluated the behavior of these two by-products of lipid peroxidation during HD, comparing their behavior in three different membranes, in order to study their reliability as markers of acute oxidative injury. Fifteen stable HD patients were dialyzed with each of the following membranes: cuprophan, polyamide, and polysulfone, three sessions for every membrane. MDA and hydroperoxides were measured pre-HD and then both from the arterial and venous line at 8, 15, 30, and 240 min. During HD with cuprophan membrane MDA decreased significantly in the venous line compared with the arterial line at 8, 15, and 30 min (P < 0.05). At the end of HD, MDA was significantly reduced compared with MDA pre-HD (P < 0.05). Plasma hydroperoxides increased significantly in the venous line compared with the arterial line at 8, 15, 30, and 240 min (P < 0.05). At the end of HD, hydroperoxides had increased significantly as compared with pre-HD (P < 0.05). When the polyamide and polysulfone membranes were used, the behavior of MDA was similar to that found with cuprophan. Hydroperoxides were unchanged during HD using both membranes. MDA is not a reliable marker of acute oxidative injury during HD as it is removed during HD. Hydroperoxide measurement is a better marker of acute oxidative injury during HD.

Changes in conjugated linoleic acid and palmitoleic acid are correlated to retinol levels in chronic renal failure in both hemodialysis and conservative treatment patients.

An increase in conjugated linoleic acid (CLA), a natural fatty acid present in our diet, which possesses anticarcinogenic and antiatherogenic activities in experimental models, has been found in both the plasma and adipose tissue of end-stage chronic renal failure (ESCRF) patients. Increased levels of retinol have also been found in those patients, due to a reduced excretion of the retinol-binding protein. Since retinol is known to influence lipid metabolism, we evaluated whether changes in retinol, CLA, and other fatty acids are correlated in the plasma of CRF patients. We measured CLA, retinol, and unsaturated fatty acids in the plasma of the following groups: (A) 35 ESCRF patients; (B) 20 hemodialysis (HD) patients; (C) 20 healthy controls. Subjects with total cholesterol and/or triglycerides higher than 250 mg/dL were excluded. We found a significant increase in CLA, retinol, palmitoleic (16:1), and oleic (18:1) acids in ESCRF patients. In HD patients we found a similar pattern, however, CLA increase was not significant. No changes were observed in the other fatty acids measured. In the groups of ESCRF and HD patients, a positive correlation between the levels of plasma retinol and CLA, and between retinol and 16:1 was found. These correlations were not detected in controls. The abnormal levels of plasma retinol in CRF patients might partly explain the changes in CLA and 16:1. The influence of retinol levels on these fatty acids might be due to an induction of delta 9 desaturase. In fact, 16:1 is known to be produced, partly, by delta 9 desaturation of palmitic acid. Moreover, the formation of CLA from delta 9 desaturation of vaccenic acid-a trans-monounsaturated fatty acid present in our diet-has recently been demonstrated in humans. Nevertheless, our data do not represent direct evidence supporting an increased delta 9 desaturase activity in CRF patients. Another possible explanation might be a variation in the exogenous intake.