Do cobalt or chromium accumulate in metal-on-metal hip arthroplasty patients who have mild, moderate, or severe renal insufficiency?

Aims To find out if there is an inverse association between estimated glomerular filtration rate (eGFR) and whole blood cobalt (Co) and chromium (Cr) levels in patients with metal-on-metal (MoM) hip arthroplasties and renal insufficiency, suggesting that renal insufficiency could cause accumulation of Co and Cr in blood. Methods Out of 2,520 patients with 3,013 MoM hip arthroplasties, we identified 1,244 patients with whole blood Co, Cr, and creatinine measured within no more than a one-year interval. We analyzed the correlation of blood metal ion levels and eGFR to identify a potential trend of accumulating Co or Cr with decreasing eGFR. Results Of the 1,244 patients, 112 had normal renal function (eGFR > 90 ml/min/1.73 m2), 715 had mild renal insufficiency (eGFR 60 to 89), 384 had moderate renal insufficiency (eGFR 30 to 59), 27 had severe renal insufficiency (eGFR 15 to 29), and six had end-stage renal insufficiency (eGFR < 15). Median eGFR was 68 ml/min/1.73 m2 (interquartile range (IQR) 56 to 82), median whole blood Co was 3.3 µg/l (IQR 1.1 to 9.9), and median Cr was 2.0 µg/l (IQR 1.2 to 3.6). We did not observe an association between decreased eGFR and increased whole blood Co and Cr concentrations, but instead both increased Co and Cr were associated with higher eGFR, indicating better kidney function. Conclusion As patients with MoM hip arthroplasties get older, the prevalence of renal insufficiency among them will increase, and orthopaedic surgeons will increasingly have to evaluate whether or not this affects patient follow-up. The USA Food and Drug Administration suggests that closer follow-up may be needed for MoM patients with renal insufficiency. We did not observe accumulation of blood Co or Cr in MoM hip arthroplasty patients with mild to severe renal insufficiency. Cite this article: Bone Joint J 2021;103-B(7):1231–1237.

P2Y12 Antiplatelet Choice for Patients with Chronic Kidney Disease and Acute Coronary Syndrome: A Systematic Review and Meta-Analysis

This study aims to evaluate potentially appropriate antiplatelet therapy in patients with chronic kidney disease. A systematic analysis was conducted to identify the clinical outcomes of available antiplatelet therapy regimens with enhanced platelet inhibition activity (intervention of 5 regimens) over the standard dose of clopidogrel-based dual antiplatelet therapy in patients with renal insufficiency. An electronic keyword search was performed on Pubmed, Embase, and Cochrane Library per PRISMA guidelines. We performed a prespecified net clinical benefit analysis (a composite of the rates of all-cause or cardiac-related death, myocardial infarction, major adverse cardiac outcomes, and minor and major bleeding), and included 12 studies. The intervention substantially lowered the incidence of all-cause mortality (RR 0.67; p = 0.003), major adverse cardiac outcomes (RR 0.79; p < 0.00001), and myocardial infarction (RR 0.28; p = 0.00007) without major bleeding (RR 1.14; p = 0.33) in patients with renal insufficiency, but no significant differences were noticed with cardiac-related mortality and stent thrombosis. The subgroup analysis revealed substantially elevated bleeding risk in patients with severe renal insufficiency or on hemodialysis (RR 1.68; p = 0.002). Our study confirmed that the intervention considerably enhances clinical outcomes in patients with renal insufficiency, however, a standard dose of clopidogrel-based antiplatelet therapy is favorable in patients with severe renal insufficiency.

The pathological features of leukemic cells infiltrating the renal interstitium in chronic lymphocytic leukemia/small lymphocytic lymphoma from a large single Chinese center

Background Chronic lymphocytic leukemia/small lymphocytic lymphoma (CLL/SLL) is rare in Asians, and patients with CLL/SLL seldomly undergo kidney biopsy. The histopathological features and clinical relevance of tubulointerstitial injury in CLL/SLL have not been extensively charaterized. Hence, we attempted to describe the clinical characteristics, renal pathology and clinical outcome of a well-characterized population of CLL/SLL patients with CLL cell infiltration in the renal interstitium from a large single center in China. Methods Between January 1st, 2010 and September 31st, 2020, 31946 renal biopsy pathologies were performed at Peking University First Hospital, and 10 CLL/SLL patients with CLL cell infiltration in the renal interstitium were included. Complete clinical data were collected from these 10 patients, and renal specimens were examined by routine light microscopy, immunofluorescence and electron microscopy. Results The extent of the infiltrating CLL cells in patients with CLL/SLL varied among different patients and ranged from 10–90% of kidney parenchyma. Six (60%) of 10 patients presented with an extent of infiltrating CLL cells ≥ 50%. Interestingly, we found that three patients (3/10, 30%) expressed monoclonal immunoglobulins in the infiltrating CLL cells, and special cytoplasmic crystalline structures were found in two of the three patients by electron micriscopy for the first time. Severe renal insufficiency (Scr ≥ 200 µmol/L ) was associated with ≥ 50% interstitial infiltration of CLL cells in the renal interstitium. Conclusions The findings confirmed that CLL cells infiltrating the renal interstitium can directly secrete monoclonal immunoglobulins, indicating that the interstitial infiltrating CLL cells probably cause renal injuriy directly by secreting monoclonal immunoglobulins in situ. This finding may prove a new clue to elucidate the pathogenetic mechanism of renal injury involved with CLL/SLL .

Atypical anti-glomerular basement membrane disease with anti-GBM antibody negativity and ANCA positivity: a case report

Background Anti-glomerular basement membrane (anti-GBM) disease is an organ-specific autoimmune disease that involves the lung and kidneys and leads to rapid glomerulonephritis progression, with or without diffuse alveolar hemorrhage, and even respiratory failure. Classic cases of anti-GBM disease are diagnosed based on the presence of the anti-GBM antibody in serum samples and kidney or lung biopsy tissue samples. However, atypical cases of anti-GBM disease are also seen in clinical practice. Case presentation We herein report the rare case of a patient with atypical anti-GBM disease whose serum was negative for the anti-GBM antibody but positive for the myeloperoxidase (MPO) anti-neutrophil cytoplasmic antibody (p-ANCA) and another atypical ANCA. Laboratory test results showed severe renal insufficiency with a creatinine level of 385 μmol/L. Renal biopsy specimen analysis revealed 100% glomeruli with crescents; immunofluorescence showed immunoglobulin G (IgG) linearly deposited alongside the GBM. Finally, the patient was discharged successfully after treatment with plasmapheresis, methylprednisolone and prednisone. Conclusion This patient, whose serum was negative for the anti-GBM antibody but positive for p-ANCA and another atypical ANCA, had a rare case of anti-GBM disease. Insights from this unusual case might help physicians diagnose rare forms of glomerulonephritis and treat affected patients in a timely manner.

Chronic Kidney Diseases Among Homeless and Slum Dwellers in Accra: A Survey Study

Objective: This study aimed at determining the prevalence of chronic kidney disease (CKD) among homeless people in Nima and Agbogbloshie, Accra, Ghana and to evaluate the association between socio‑demographic characteristics and CKD. Results: Participants with normal serum creatinine (SCr), made up of 232 males and 280 females totaling 512 took part in the study. Those with normal glomerular filtration rate (GFR) were 86% and 84.6% by means of the C-G and MDRD equations respectively. According to the C-G formula, kidney damage and mild to severe renal insufficiency was found in 13.2% of the participants and 4 participants (0.8%) had renal failure. On the other hand, 15.4% of the participants were found to have some kidney damage and mild to severe renal insufficiency according to the MDRD formula with no participant suffering from kidney failure. The prevalence of renal dysfunction among the homeless Ghanaians was significant especially among those with hypertension, diabetes and human immunodeficiency syndrome virus (HIV) infection. . Intensive social support aimed at preventing and managing kidney disease is crucial if we are to reduce the incidence of kidney related illnesses in homeless people.

Assessment of Thrombotic and Bleeding Tendency in Two Mouse Models of Chronic Kidney Disease: Adenine-Diet and 5/6th Nephrectomy

The coexistence of bleeding and thrombosis in patients with chronic kidney disease (CKD) is frequent and poorly understood. Mouse models are essential to understand complications of CKD and to develop new therapeutic approaches improving the health of patients. We evaluated the hemostasis in two models of renal insufficiency: adenine-diet and 5/6th nephrectomy (5/6Nx). Compared with 5/6Nx mice, mice fed with 0.25% adenine had more severe renal insufficiency and so higher levels of prothrombotic uremic toxins like indoxyl sulfate. More severe renal inflammation and fibrosis were observed in the adenine group, as demonstrated by histological and reverse transcription quantitative polymerase chain reaction experiments. Liver fibrinogen γ chain expression and level of plasma fibrinogen were increased only in adenine mice. In both CKD mouse models, tissue factor (TF) expression was increased in kidney and aorta extracts. Immunochemistry analysis of kidney sections showed that TF is localized in the vascular walls. Thrombin–antithrombin complexes were significantly increased in plasma from both adenine and 5/6Nx mice. Tail bleeding time increased significantly only in adenine mice, whereas platelet count was not significant altered. Finally, results obtained by intravital microscopy after laser-induced endothelial injury showed impaired platelet function in adenine mice and an increase in fibrin generation in 5/6Nx mice. To summarize, adenine diet causes a more severe renal insufficiency compared with 5/6Nx. The TF upregulation and the hypercoagulable state were observed in both CKD models. Bleeding tendency was observed only in the adenine model of CKD that recapitulates the whole spectrum of hemostasis abnormalities observed in advanced human CKD.