Kidney Function

Intradialytic hypertension, defined as an increase in blood pressure during or immediately after hemodialysis that results in postdialysis hypertension, has long been recognized to complicate the hemodialysis procedure, yet often is largely ignored. In light of recent investigations suggesting that intradialytic hypertension is associated with adverse outcomes, this review broadly covers the epidemiologic characteristics, prognostic significance, potential pathogenic mechanisms, prevention, and possible treatment of intradialytic hypertension. Intradialytic hypertension affects up to 15% of hemodialysis patients and occurs more frequently in patients who are older, have lower dry weights, are prescribed more antihypertensive medications, and have lower serum creatinine levels. Recent studies associated intradialytic hypertension independently with higher hospitalization rates and decreased survival. Although the pathophysiologic mechanisms of intradialytic hypertension are uncertain, it likely is multifactorial and includes subclinical volume overload, sympathetic overactivity, activation of the renin-angiotensin system, endothelial cell dysfunction, and specific dialytic techniques. Prevention and treatment of intradialytic hypertension may include careful attention to dry weight, avoidance of dialyzable antihypertensive medications, limiting the use of high-calcium dialysate, achieving adequate sodium solute removal during hemodialysis, and using medications that inhibit the renin-angiotensin-aldosterone system or decrease endothelin 1 levels. In summary, although intradialytic hypertension often is underappreciated, recent studies suggest that it should not be ignored. However, further work is necessary to elucidate the pathophysiologic mechanisms of intradialytic hypertension and its appropriate management and determine whether treatment of intradialytic hypertension can improve clinical outcomes.

Light chain tubulopathy is a rare complication associated with plasma cell dyscrasias. There are no more than 80 cases reported in the English literature; the defining series was 17 patients described by Maldonado et al in 1975. That original work showed in patients with acquired Fanconi syndrome an association with monoclonal immunoglobulin light chain proteinuria, slow progression of the plasma cell dyscrasia, and crystal formation in proximal tubule cells. Since that time, a variety of clinical and pathologic findings have been reported with respect to light chain tubulopathy. Messiaen et al reported a series of 11 cases, 3 of which had no crystal formation, 2 had only partial Fanconi syndrome, and the degree of plasma cell dyscrasia ranged from monoclonal gammopathy of undetermined significance (MGUS) to full-blown multiple myeloma. The timing of kidney manifestations in relation to the diagnosis of plasma cell dyscrasia also varies. Most reports show that the investigation of proteinuria, kidney failure, Fanconi syndrome, or osteomalacia leads to the discovery of plasma cell dyscrasia; however, there are instances in which light chain tubulopathy proceeded the diagnosis of plasma cell dyscrasia. Additionally, light chain tubulopathy rarely occurs without Fanconi syndrome, as was described recently in 1 case report. We report a case of light chain tubulopathy without Fanconi syndrome found to have significant crystalline inclusions in tubular epithelial cells and podocytes discovered many years after the diagnosis of MGUS.

Background: Chronic kidney disease (CKD) is a major cause of morbidity and mortality in Mexico. However, many residents of underserved areas may be unaware that they potentially are affected.Study Design: In an observational cross-sectional study, we examined the diagnostic yield of screening for CKD and cardiovascular disease risk factors using mobile units that traveled to poor communities in Jalisco, Mexico.Setting & Participants: We excluded individuals who were aware that they had CKD and those < 18 years of age.Outcomes: Glomerular filtration rate, cardiovascular risk.Measurements: Demographic data, socioeconomic status, blood pressure, fasting glucose, and dipstick urinalysis.Results: 3,734 participants; 29.3% men and mean age of 57.4 ± 13.0 years. Most (99.7%) had no history of cardiovascular disease; however, 43.5% had a history of diabetes, 11.4% had dipstick-positive proteinuria, 62.0% had blood pressure in the hypertensive range, and 15.8% had an estimated glomerular filtration rate compatible with stages 3-5 CKD. In patients with no history of cardiovascular disease, proportions with predicted 5-year risks of new cardiovascular events <5%, 5%-10%, 10.1%-20%, 20.1%-30%, and >30% were 10.0%, 11.7%, 26.6%, 20.7%, and 30.9%, respectively. Screening 18 participants aged < 40 years would be expected to detect 6 new cases of hypertension or 2 new cases of diabetes.Limitations: Data may not be generalizable to all low-income settings or other regions of Mexico.Conclusions: Impaired kidney function, proteinuria, and cardiovascular risk factors were detected frequently when mobile units were used to perform screening in poor areas of Jalisco, Mexico. This suggests that trials of targeted screening and intervention are feasible and warranted.