Vascular calcification in kidney stone formers: the impact of age and stone composition.

An increased prevalence of vascular calcification (VC) has been reported in kidney stone formers (KSFs), along with an elevated cardiovascular risk. The aim of the current study is to assess whether VC in these patients develops at a younger age and is influenced by stone composition. This single-center, matched case-control study included KSFs with uric acid or calcium oxalate stones (diagnosed based on stone analysis) and age- and sex-matched controls without a history of nephrolithiasis. The prevalence and severity of abdominal aortic calcification (AAC) and bone mineral density (BMD) were compared between KSFs and non-KSFs. In total, 335 patients were investigated: 134 with calcium oxalate stones, 67 with uric acid stones, and 134 controls. Overall, the prevalence of AAC was significantly higher among calcium stone formers than among the controls (67.9% vs. 47%, p = 0.002). In patients under 60 years of age, those with calcium oxalate stones exhibited both a significantly elevated AAC prevalence (61.9% vs. 31.3%, p = 0.016) and severity (94.8 ± 15.4 vs. 30.3 ± 15.95, p = 0.001) compared to the controls. Within the age group of 40-49, osteoporosis was identified only in the KSFs. Multivariate analysis identified age, smoking, and the presence of calcium stones as independent predictors of AAC. This study highlights that VC and osteoporosis occur in KSFs at a younger age than in non-stone-formers, suggesting potential premature VC. Its pathogenesis is intriguing and needs to be elucidated. Early evaluation and intervention may be crucial for mitigating the cardiovascular risk in this population.

Successful Treatment with Daratumumab of a Patient with Monoclonal Lambda Light Chain Disease Presenting as Nephrotic Syndrome and Crescentic Glomerulonephritis.

INTRODUCTION: Monoclonal immunoglobulin deposition diseases (MIDDs) are a group of systemic diseases, characterized by deposition of monoclonal immunoglobulin predominantly in the kidney. In the absence of overt hematologic disease, MIDDs are classified as a part of monoclonal gammopathy of renal significance. Patients with MIDD may present with a nephrotic syndrome and kidney function impairment. Treatment usually includes anti-plasma cell therapy. CASE PRESENTATION: We report a case of a 54-year-old female who presented with nephrotic syndrome related to light chain deposition disease of lambda type. Due to a complicated clinical course (including cardiac injury and thromboembolic stroke), plasma cell-targeted therapy was stopped. A few months later, the patient presented with severe acute kidney injury. Kidney biopsy revealed crescentic glomerulonephritis, and immunofluorescence staining was positive for lambda chain. Treatment with daratumumab was initiated resulting in stabilization of kidney function and partial nephrotic syndrome remission. CONCLUSION: This case highlights an uncommon histologic manifestation in a patient diagnosed with light chain deposition disease. Furthermore, it underscores the significance of plasma cell-targeted therapy and the favorable clinical and hematological response observed with daratumumab.

Pseudohyperkalemia in chronic lymphocytic leukemia: Prevalence, impact, and management challenges.

The term pseudohyperkalemia refers to a false elevation in serum potassium levels due to potassium release from cells in vitro. Falsely elevated potassium levels have been reported in patients with thrombocytosis, leukocytosis, and hematologic malignancies. This phenomenon has been particularly described in chronic lymphocytic leukemia (CLL). Leukocyte fragility, extremely high leukocyte counts, mechanical stress, higher cell membrane permeability related to an interaction with lithium heparin in plasma blood samples, and metabolite depletion due to a high leukocyte burden have been reported to contribute to pseudohyperkalemia in CLL. The prevalence of pseudohyperkalemia is up to 40%, particularly in the presence of a high leukocyte count (>50 × 109/L). The diagnosis of pseudohyperkalemia is often overlooked, which may result in unnecessary and potentially harmful treatment. The use of whole blood testing and point-of-care blood gas analysis, along with thorough clinical evaluation, may help differentiate between true and pseudohyperkalemic episodes.

Acute Kidney Injury and Hair-Straightening Products: A Case Series.

RATIONALE & OBJECTIVE: Keratin-based hair-straightening treatment is a popular hair-styling method. The majority of keratin-based hair-straightening products in Israel contain glycolic acid derivatives, which are considered safe when used topically. Systemic absorption of these products is possible, and anecdotal reports have described kidney toxicity associated with their use. We report a series of cases of severe acute kidney injury (AKI) following use of hair-straightening treatment in Israel during the past several years. STUDY DESIGN: Case series. SETTING & PARTICIPANTS: We retrospectively identified 26 patients from 14 medical centers in Israel who experienced severe AKI and reported prior treatment with hair-straightening products in 2019-2022. FINDINGS: The 26 patients described had a median age of 28.5 (range, 14-58) years and experienced severe AKI following a hair-straightening procedure. The most common symptoms at presentation were nausea, vomiting, and abdominal pain. Scalp rash was noted in 10 (38%) patients. Two patients experienced a recurrent episode of AKI following a repeat hair-straightening treatment. Seven patients underwent kidney biopsies, which demonstrated intratubular calcium oxalate deposition in 6 and microcalcification in tubular cells in 1. In all biopsies, signs of acute tubular injury were present, and an interstitial infiltrate was noted in 4 cases. Three patients required temporary dialysis. LIMITATIONS: Retrospective uncontrolled study, small number of kidney biopsies. CONCLUSIONS: This series describes cases of AKI with prior exposure to hair-straightening treatments. Acute oxalate nephropathy was the dominant finding on kidney biopsies, which may be related to absorption of glycolic acid derivatives and their metabolism to oxalate. This case series suggests a potential underrecognized cause of AKI in the young healthy population. Further studies are needed to confirm this association and to assess the extent of this phenomenon as well as its pathogenesis.

Incidence, risk factors, and recognition of pseudohyperkalemia in patients with chronic lymphocytic leukemia.

Pseudohyperkalemia, a false elevation of potassium level in vitro, can be observed in chronic lymphocytic leukemia (CLL) patients due to fragility of leukocytes along with a high leukocyte count. This retrospective, observational study included all patients diagnosed with CLL at our hospital who had at least one leukocyte count ≥ 50.0 × 109/L during the years 2008-2018. All hyperkalemic episodes (including when leukocyte count was below 50.0 × 109/L) during this period were assessed. Pseudohyperkalemia was defined as when a normal potassium level was measured in a repeated blood test or when known risk factors and ECG changes typical of hyperkalemia were absent. Of the 119 episodes of hyperkalemia observed, 41.2% were considered as pseudohyperkalemia. Pseudohyperkalemia episodes were characterized by significantly higher leukocyte counts as well as higher potassium and LDH levels compared to true hyperkalemia. Pseudohyperkalemia was documented in medical charts only in a minority of cases (n = 4, 8.1%). Treatment was administered in 17 of 49 (34.7%) cases and caused significant hypokalemia in 6 of those cases. The incidence of pseudohyperkalemia in this study was rather high, suggesting that physicians should be more aware of this phenomenon in patients with CLL.

Labile plasma iron levels in chronic hemodialysis patients treated by intravenous iron supplementation.

The increased usage of intravenous iron in hemodialysis patients during recent years has led to increasing concern over the potential development of iron overload. Current methods for detecting iron overload, transferrin saturation, and serum ferritin are neither sensitive nor specific. Labile plasma iron (LPI) represents a component of nontransferrin-bound iron and may be a more accurate indicator of impending iron overload. We studied whether LPI measured can serve as an early indicator of impending iron overload and mortality in hemodialysis patients. Chronic hemodialysis patients from two medical centers in Israel and Poland who received intravenous iron were included. Baseline clinical and laboratory parameters were recorded. LPI was measured before and 48 hours after a single IV administration. Correlation of positive LPI with laboratory parameters and 2-year mortality was evaluated. One hundred and one hemodialysis patients were included in the study. LPI became positive post-administration in 18 (17.8%) patients. Ferritin levels >526 ng/mL and monthly iron doses >250 mg were associated with positive LPI after intravenous iron. At a 2-year follow-up, higher mortality was observed in the positive LPI group (61.1% compared to 25.3%, P ≤ .05), although this effect was not statistically significant after multivariate adjustment. A substantial number of hemodialysis patients have positive LPI after intravenous iron administration. LPI positively correlates with laboratory parameters that are currently in routine clinical use for detecting iron overload and with higher intravenous iron dose. Further studies should be conducted to establish the clinical implications of LPI monitoring in hemodialysis patients.

[Giant cell arteritis--old questions, current answers].

Giant cell arteritis (GCA) is the most common systemic vasculitis in the elderly. Over several decades there has been an increase in its incidence, although this trend has changed in North America, northern Europe and in Israel. The signs and symptoms of GCA can be classified into four general subsets: manifestations of cranial arteritis, extra-cranial arteritis, systemic symptoms and polymyalgia rheumatica (PMR). The diagnosis is based on clinical characteristics and established by the presence of inflammatory markers. However, the only specific diagnostic test is a temporal artery biopsy. The optimal length of the biopsy appears to be between 10- 20 mm. Bilateral biopsies may increase the diagnostic yield. Patients with "biopsy negative giant cell arteritis" are characterized by older age, more headaches at presentation and thrombocytosis. Some imaging modalities may aid in the diagnosis of GCA. The most commonly used is color duplex ultrasound of the temporal arteries, showing the "dark halo sign" in characteristic cases. This modality has high specificity (around 90%), and is useful for ruling out a diagnosis in low risk patients. Glucocorticoids are the treatment of choice in GCA. The addition of anti-platelet drugs (such as low-dose aspirin (100 mg/d)) has been shown to decrease the ischemic complication rate significantly during the course of the disease. Nevertheless, there are no effective steroid sparing drugs for GCA. Methotrexate may be considered in a subgroup of high risk patients.