Case report: disease mechanisms and medical management of calcium nephrolithiasis in rheumatologic diseases.

BACKGROUND: Nephrolithiasis as a feature of rheumatologic diseases is under recognized. Understanding presenting features, diagnostic testing is crucial to proper management. CASE PRESENTATION: A 32 year old woman with a history of recurrent complicated nephrolithiasis presented to a rheumatologist for a several month history of fatigue, dry eyes, dry mouth, arthralgias. She had a positive double-stranded DNA, positive SSA and SSB antibodies. She was diagnosed with Systemic Lupus erythematosus (SLE) and Sjogren's syndrome and was started on mycophenalate mofetil. Of relevance was a visit to her local emergency room 4 years earlier with profound weakness with unexplained marked hypokalemia and a non-anion gap metabolic acidosis. Approximately one year after that episode she developed flank pain and nephrocalcinosis. She had multiple issues over the ensuing years with stones and infections on both sides. Interventions included extracorporeal shockwave lithotripsy as well as open lithotomy and eventual auto-transplantation of left kidney for recurrent ureteric stenosis. 24 h stone profile revealed marked hypocitraturia, normal urine calcium, normal urine oxalate and uric acid. She was treated with potassium citrate. Mycophenolate was eventually stopped due to recurrent urinary tract infections and she was started on Belimumab. Because of recurrent SLE flares, treatment was changed to Rituximab (every 6 months) with clinical and serologic improvement. Her kidney stone frequency gradually improved and no further interventions needed although she continued to require citrate repletion for hypocitraturia. CONCLUSIONS: Nephrolithiasis can be a prominent and even presenting feature in Sjogrens syndrome as well as other rheumatologic diseases. Prompt recognition and understanding disease mechanisms is important for best therapeutic interventions for kidney stone prevention as well as treatment of underlying bone mineral disease.

Effect of intravenous iron on outcomes of acute kidney injury.

BACKGROUND: Little is known about benefit versus risk in treating iron deficiency anemia with intravenous (IV) iron in patients with acute kidney injury (AKI). Concerns about adverse outcomes may dissuade use and could contribute to greater use of red blood cell (RBC) transfusion. STUDY DESIGN AND METHODS: We performed a retrospective case-control study of patients with AKI who received IV iron (cases) compared to those with AKI without IV iron (controls). RESULTS: We identified 67 cases and 67 controls matched for age, stage of chronic kidney disease, and severity of anemia (hemoglobin [Hb], 7.7 ± 0.1 mg/dL vs. 7.5 ± 0.1 mg/dL; p = 0.47). Cases tended to be sicker with longer length of stay (27 + 4 days vs. 15 + 1.3 days; p = 0.003) and more intensive care unit days (13 + 2 days vs. 5 + 1 days; p = 0.003), more often with diagnosis of sepsis and greater number of antibiotics used (2.7 ± 0.3 vs. 1.8 ± 0.2; p = 0.02). Sepsis and AKI preceded use of IV iron. Despite greater illness severity, there was no difference in dialysis (38.8% vs. 34.3%; p = 0.59), mortality (24% vs. 21%; p = 0.679), or severity and/or recovery of AKI. Discharge Hb was similar (9.0 ± 0.1 mg/dL vs. 9.1 ± 0.1 mg/dL; p = 0.47). IV iron was used later in the stay and hence the cases also had more RBC transfusions. CONCLUSIONS: We were unable to find any adverse consequences of use of IV iron when used to treat anemia in patients with AKI in regard to recovery of AKI or mortality even in patients with a diagnosis of sepsis. Consideration of preemptive use of IV iron in AKI with severe anemia is warranted to determine if this would reduce RBC transfusion.

Evaluation and outcome of proteinuria in older and younger adults.

BACKGROUND: The spectrum of proteinuric renal disease in older adults remains incompletely defined. The purpose of the present study was to determine if differences exist in diagnostic approach, etiology, therapy, and outcome between older (> or = 60 years) and younger (<60 years) patients referred for evaluation of proteinuria. METHODS: We conducted a retrospective review of outpatient office charts in a 7-physician, hospital-based nephrology practice. RESULTS: We identified 69 patients with at least 1 subsequent follow-up assessment after reviewing approximately 500 sequential charts. Forty-five were younger (mean +/- SD age, 38 +/- 2 years), and 24 were older (69 +/- 1 years). The degree of proteinuria at presentation was similar (4.5 +/- 0.7 vs 3.9 +/- 0.6 g/d, older vs younger, p = NS), but older patients had higher creatinine levels (1.7 +/- 0.2 vs 1.2 +/- 0.07 mg/dl, p <.01), lower creatinine clearances (64 +/- 7 vs 111 +/- 7 ml/min., p <.05), and higher systolic blood pressure (164 +/- 8/88 +/- 2 vs 145 +/- 4/94 +/- 2 mm Hg, p <.01). Older patients were more likely to decline a renal biopsy (21% vs 7.6%, p <.01). The most common final renal diagnoses were immunoglobulin A nephropathy (31%), focal segmental glomerulosclerosis (24%), hypertension (13%), and membranous nephropathy (11%) in the younger patients, and membranous nephropathy (29%), hypertension (25%), diabetic nephropathy (17%), and minimal change disease (8%) in the older patients. Steroids were given to 17.7% of younger patients and 16.7% of older patients (p = NS). The percentage of patients with improvement, defined as a 50% reduction in proteinuria with stable or improved renal function, was similar among older and younger patients (33.3% vs 35.5%). However, older patients were more likely to develop progression of renal disease (33.3% vs 8.8%) and less likely to retain stable renal function (29.2% vs 53.3%). CONCLUSION: Significant differences exist in proteinuric renal disease between older and younger adults.

Gender as a risk factor for contrast nephropathy: effects of hydration and N-acetylcysteine.

BACKGROUND: In a few studies, N-acetylcysteine has been shown to prevent contrast-induced nephropathy in patients with chronic, stable renal failure undergoing elective procedures. Other studies have shown variable outcomes. Furthermore, the majority of prior studies have mainly studied men, and gender as a risk factor has not been studied. HYPOTHESIS: The study sought to evaluate the effectiveness of N-acetylcysteine and hydration in unselected patients with both acute and stable renal insufficiency (RI) undergoing urgent or elective cardiac or peripheral angiography. METHODS: We evaluated records of 146 patients with RI undergoing angiography. We compared patients receiving periprocedure hydration and acetylcysteine with patients who were only hydrated or received no pretreatment. We evaluated the 48-h change in serum creatinine between groups and further analyzed the effect of hydration and gender on outcomes. RESULTS: Demographics and baseline creatinine were similar between groups. Post procedure, the creatinine increased significantly in both groups, but less so in the acetylcysteine group (control: 0.35 +/- 0.08 mg/dl; acetylcysteine: 0.14 +/- 0.04 mg/dl, p < 0.05). When the control group was further stratified by hydration, the increase in creatinine for the hydrated patients was only 0.17 +/- 0.10 mg/dl compared with 0.54 +/- 0.12 mg/dl in patients with inadequate hydration. In the control group, women were more likely to receive no preprocedural hydration (59 vs. 40%), had a bigger rise in creatinine, received less protection from hydration alone, but were equally well protected by hydration plus acetylcysteine. In the acetylcysteine group, change in creatinine for women was minimal (+ 0.14 +/- 0.07 mg/dl) and not different from men (+ 0.15 +/- 0.05). CONCLUSION: Unselected patients with acute and chronic RI had no benefit from acetylcysteine beyond that seen with hydration alone. Gender may be a risk factor for contrast-induced nephropathy, with hydration offering less protection in women. Acetylcysteine (with hydration) seems to minimize the gender difference.

Steroid-responsive nephrotic syndrome and bilateral renal artery stenosis: a possible role for Angiotensin-mediated podocyte injury.

Nephrotic syndrome (NS) associated with renal artery stenosis is not widely recognized or investigated as a cause of the NS. The mechanisms are incompletely understood, but have largely focused on hemodynamic factors resulting in hyperfiltration injury-induced focal and segmental glomerulosclerosis (FSGS) in the nonstenosed kidney with sparing of the stenotic kidney protected from hemodynamic stress. However, separation of hemodynamic from circulating factors (such as angiotensin II) as the cause of the nephrosis remains difficult. We report a patient presenting with NS who was incidentally discovered to have high-grade bilateral renal artery stenosis from fibromuscular dysplasia. Kidney biopsy revealed FSGS. Proteinuria in our patient did not initially respond to angiotensin-converting enzyme inhibition (ACEI) and correction of stenoses with angioplasties. There was prompt response to steroid treatment. A brief relapse several months later (without associated hypertension) responded to ACEI alone. This is the first reported case of an association between fibromuscular dysplasia and steroid-responsive nephrotic syndrome due to FSGS. This may shed insight into the nature of podocyte injury in patients with high angiotensin states and suggest a possible role for activated renin-angiotensin-aldosterone system (RAAS) triggering an immune-mediated injury, rather than hemodynamic insult. Furthermore the lack of initial response to angioplasty and ACEI suggests that RAAS-activated injury may in some cases require more aggressive immune modulatory therapy with steroids over and above angiotensin inhibition alone. This case also highlights the importance of being aware of possible occult renovascular disease contributing to idiopathic NS with FSGS even when hypertension is only modest.

Nephroptosis in a young woman with joint laxity.

BACKGROUND: A 25-year-old woman was evaluated repeatedly from 10 months following her first pregnancy and delivery for recurrent episodes of lower right quadrant abdominal pain, hematuria and a sensation of mass. Despite investigations by several physicians over a 7 month period no clear diagnosis had been made, but a psychosomatic disorder or possible periodic blocked bowel had been suggested, after which the patient requested a consultation with a nephrologist. Her history indicated joint laxity syndrome and a mitral valve prolapse. She was undergoing continuing evaluation for a possible rheumatic condition. INVESTIGATIONS: Full history, physical examination, and intravenous pyelography. DIAGNOSIS: Nephroptosis of the right kidney. INTERVENTION: Exercises were prescribed to strengthen her abdominal musculature and she was advised to wear an elastic abdominal corset during the daytime. The patient is currently considering surgical intervention.