Lung ultrasonography performed by nephrologist: COVID-19 as an opportunity to reveal ultrasound's full potential and usefulness in the dialysis room.

Background: Interest in point-of-care ultrasound (POCUS) and lung ultrasound (LUS) is growing in the nephrology and dialysis field, and the number of nephrologists skilled in what is proving to be the "5th pillar of bedside physical examination" is increasing. Patients on hemodialysis (HD) are at high risk of contracting severe acute respiratory syndrome coronavirus 2 (SARS-COV-2) and developing coronavirus disease 2019 (COVID-19) serious complications. Despite this, to our knowledge there are no studies to date that show the role of LUS in this setting, while there are many in the emergency room, where LUS proved to be an important tool, providing risk stratification and guiding management strategies and resource allocation. Therefore, it is not clear whether the usefulness and cut-offs of LUS highlighted in studies in the general population are reliable in dialysis, or whether variations, precautions and adjustments to this specific situation are necessary. Methods: This was a 1-year monocentric prospective observational cohort study of 56 HD patients with COVID-19. Patients underwent a monitoring protocol that included at first evaluation bedside LUS, using a 12-scan scoring system, by the same nephrologist. All data were prospectively and systematically collected. Outcomes. hospitalization rate, combined outcome [non-invasive ventilation (NIV + death)], mortality. Descriptive variables are presented as medians (interquartile range), or percentage. Univariate and multivariate analysis, as well as Kaplan-Meier (K-M) survival curves, were carried out. P was fixed at .05. Results: Median age was 78 years, 90% had at least one comorbidity (46% diabetics), 55% were hospitalized and 23% deaths. Median duration of disease was 23 days (14-34). A LUS score ≥11 represented a 13-fold risk of hospitalization, a 16.5-fold risk of combined outcome (NIV + death) vs risk factors such as age [odds ratio (OR) 1.6], diabetes (OR 1.2), male sex (OR 1.3) and obesity (OR 1.25), and a 7.7-fold risk of mortality. In the logistic regression, LUS score ≥11 is associated with the combined outcome with a hazard ratio (HR) of 6.1 vs inflammations indices such as CRP ≥9 mg/dL (HR 5.5) and interleukin-6 (IL-6) ≥62 pg/mL (HR 5.4). In K-M curves, survival drops significantly with LUS score above 11. Conclusions: In our experience of COVID-19 HD patients, LUS appeared to be an effective and easy tool, predicting the need for NIV and mortality better than "classic" known COVID-19 risk factors such as age, diabetes, male sex and obesity, and even better than inflammations indices such as CRP and IL-6. These results are consistent with those of the studies in the emergency room setting, but with a lower LUS score cut-off (11 vs 16-18). This is probably due to the higher global frailty and peculiarity of HD population, and emphasizes how nephrologists should themselves use LUS and POCUS as a part of their everyday clinical practice, adapting it to the peculiarity of the HD ward.

[COVID-19 recurrence due to reinfection with SARS-CoV-2 in a hemodialysis patient: there and back again].

The COVID-19 pandemic has caused millions of infections and deaths so far. After recovery, the possibility of reinfection has been reported. Patients on hemodialysis are at high risk of contracting SARS-CoV-2 and developing serious complications. Furthermore, they are a relatively hypo-anergic population, in which the development and duration of the immune and antibody response is still partially unknown. This may play a role in the possible susceptibility to reinfection. To date, only 3 cases of SARS-CoV-2 reinfection from strains prior to the Omicron variant in patients on chronic hemodialysis have been reported in literature. In all of them, the first infection was detected by screening in the absence of symptoms, potentially indicating a poor immune response, and there are no data about the antibody titre developed. We report a case of recurrence of COVID-19 in 2020 - first infection likely from Wuhan strain; reinfection likely from English variant (Alpha) after 7 months - in a hemodialysis patient with clinical symptoms and pulmonary ultrasound abnormalities. Swabs were negative in the interval between episodes (therefore excluding any persistence of positivity) and the lack of antibody protection after the first infection was documented by the serological test. The role of the potential lack - or rapid loss - of immune protection following exposure to SARS-CoV-2 in hemodialysis patients needs to be better defined, also in consideration of the anti-COVID vaccination campaign and the arrival of the Omicron variant, which appears to elude the immunity induced by vaccines and by previous variants. For this purpose, prospective multicenter studies are in progress in several European countries. This case also highlights the need for a careful screening with nasopharyngeal swabs in dialysis rooms, even after patients overcome infection and/or are vaccinated.

Cholesterol crystal embolism syndrome in dialysis patients: an emerging clinical diagnosis?

BACKGROUND: Cholesterol crystal embolism syndrome (CCE) is an increasing end-stage renal disease cause. Few cases have been described on dialysis, despite the high prevalence of the predisposing factors. METHODS: The diagnostic criteria of the present study were: skin lesions, myalgia, fatigue, fever and acute inflammatory serologic signs, in the presence of severe vasculopathy. The precipitating factors were: anticoagulation, endovascular intervention and ulcerated atherosclerotic plaque. RESULTS: Between October 2003 and September 2005, CCE was diagnosed in 6 dialysis patients (of 200-210 on chronic treatment): 5 males, 1 female, median age 59.5 years (47-70) and end-stage renal disease follow-up 11.5 years (3-25). All had severe vasculopathy, 5 cardiopathy, and 4 were failed graft recipients. The treatment included: peritoneal dialysis, daily dialysis, 'conventional' hemodialysis (2 cases) and hemodiafiltration. The diagnosis was based on the clinical-laboratory picture in 1 patient. In the 5 others clues were present (dicumarol therapy, angioplasty, femoral artery thrombosis, CCE predialysis and ulcerated aortic plaque). The therapeutic approach consisted of corticosteroids (5 cases), statins (4 cases) and prostaglandin analogues (4 cases). CONCLUSION: The differential diagnosis of CCE should also be considered in dialysis patients (necrotic lesions, limb pain and vasculitis-like signs).

Cholesterol emboli syndrome in type 2 diabetes: the disease history of a case evaluated with renal scintigraphy.

BACKGROUND: Cholesterol crystal emboli syndrome (CCE) is an emerging disease, whose progression reflects the currently observed increase in cardiovascular diseases. Diagnostic criteria shifted from pathological to clinical criteria: creatinine increase, skin lesions, recent endovascular interventions and severe vasculopathy). Diabetes, hypertension and diffuse vascular disease are inter-linked, major risk factors. The role of imaging techniques in the diagnosis and treatment of the disease has been little investigated thus far. The AIM of this report is to describe a case exemplifying the potentials for renal scintigraphy in CCE, an emerging disease in type 2 diabetic patients. THE CASE: A 75 year-old, type 2 diabetic for over 15 years, obese, hypertensive white man was referred to the Nephrology Unit after an acute coronary syndrome. Stenosis of the left renal artery was diagnosed from the angiography. Serum creatinine (baseline: 1.9 mg/dl) increased after multiple angioplasties to 3.3 mg/dl, then slowly returned towards baseline (2.2 mg/dl), but rose, on referral, to 3.9 mg/dl, with an increase in acute phase reactants and peripheral livedo reticularis, a picture highly suggestive of CCE. The first renal scintiscan showed a reduction of the parenchymal phase, and a non-homogeneous parenchymal pattern in the right dominant kidney. The patient was started on corticosteroid therapy with a prompt decrease in creatinine; four days later (creatinine 2.5 mg/dl) a second scintiscan showed an improvement of the peak time and of the radionuclide parenchymal transit, and was further confirmed two months later (creatinine 2.2 mg/dl). No modification was detected in the left kidney, presumably mechanically "protected" from the cholesterol shedding by the stenosis. CONCLUSIONS: This is the first description of an imaging demonstration of the morpho-functional substratum to the rapid clinical response of corticosteroid therapy in a case of CCE and type 2 diabetes, underlining the potential of 99mTc-MAG3 dynamic scintiscan in this disease.