IgA vasculitis (Henoch-Schönlein purpura): refractory and relapsing disease course in the adult population.

BACKGROUND: The disease course of adult immunoglobulin A (IgA) vasculitis (IgAV; Henoch-Schönlein purpura) has not been well defined. METHODS: In a retrospective survey, we studied 85 adult IgAV patients with extended follow-up (median 43 months) for 67 patients. RESULTS: Only 33 of 67 (49%) achieved complete remission. Ongoing renal disease was the most common persistent organ manifestation, but extra-renal disease activity was also present in >50% of patients not achieving complete remission. Twenty-nine of 67 (43%) had relapsing disease, with 18/67 (27%) experiencing several relapses. Skin disease was the most common feature in relapsing patients, followed by nephritis. At 4 years of follow-up, 6 of 29 (21%) experienced progressive disease and 10/29 (34%) relapsing disease. Five of 67 (7%) developed nephritis after diagnosis, within the first 6 months of follow-up. At final follow-up, 10 of 67 (15%) had chronic kidney disease Stage ≥G3a, 18 (27%) haematuria and 13 (19%) proteinuria. No therapy appeared particularly effective and only 6/17 patients treated with mycophenolate mofetil experienced a good response. CONCLUSIONS: The disease course of adult IgAV is different from that seen in children, with higher frequency of persisting and relapsing disease. Renal disease is the main determinant of ongoing disease activity, but extra-renal features were seen in >50% of patients with chronic disease activity. No clear conclusions on use or choice of immunosuppressive agent could be made based on our experience

Randall’s plaque as the origin of idiopathic calcium oxalate stone formation: an update

International audienc

Using mid infrared to perform investigations beyond the diffraction limits of microcristalline pathologies: advantages and limitation of Optical PhotoThermal IR spectroscopy

Understanding the physico-chemistry related to cristalline pathologies constitutes a challenge in several medical specialities such as nephrology, dermatology or oncology. Regarding nephrology, the chemical diversity of concretions such as kidney stones calls for characterization techniques to determine the chemical composition of concretions. The starting point of this contribution is given by Fourier Transform InfraRed (FTIR) spectroscopy which is routinely used at the hospital to determine the chemical composition of kidney stones as well as ectopic calcifications present in kidney biopsy. For kidney stones, the quantity of sample is sufficient to perform a significant analysis through classical FTIR. For ectopic calcifications, $\mu$FTIR can be inefficient in the case of $\mu$calcification in the tissue when their size is less than 10 $\mu$m. For such samples, Optical PhotoThermal IR (OPT-IR) spectroscopy may constitute a way to overcome this experimental difficulty through the acquisition of IR spectrum with a spatial resolution close to 500 nm.To illustrate such opportunity, we first compare the IR spectrum acquired with a classical experimental set-up related to classical IR spectroscopy to IR spectrum collected with a OPT-IR one for different compounds namely calcium oxalate monohydrate, calcium oxalate dehydrate, calcium phosphate apatite and magnesium ammonium phosphate hexahydrate. Such comparison helps us to assess specificity of OPT-IR. Then, we consider several pathological calcifications associated to hyperoxaluria, adenine phosphoribosyltransferase (APRT) deficiency or the presence of Randall’s plaque. We will see that the nanometer spatial resolution constitutes a major advantage versus a micrometre one. Also, in the case of Randall’s plaque, we show that OPT-IR can determine the chemical composition of microscopic concretion without any kind of preparation. Such experimental fact is clearly a major advantage. Finally, we also extended this first investigation in nephrology by considering breast calcifications. In that case, if the number of chemical phases is quite low compared to the number of chemical phases identified in ectopic calcifications present in kidney (four instead of 24), the challenge is related to the possibility to distinguish between the different calcium phosphate namely amorphous carbonated calcium phosphate, CA and whitlockite.The complete set of data indicates the limitations and the advantages of OPT-IR spectroscopy

Using mid infrared to perform investigations beyond the diffraction limits of microcristalline pathologies: advantages and limitation of Optical PhotoThermal IR spectroscopy

Understanding the physico-chemistry related to cristalline pathologies constitutes a challenge in several medical specialities such as nephrology, dermatology or oncology. Regarding nephrology, the chemical diversity of concretions such as kidney stones calls for characterization techniques to determine the chemical composition of concretions. The starting point of this contribution is given by Fourier Transform InfraRed (FTIR) spectroscopy which is routinely used at the hospital to determine the chemical composition of kidney stones as well as ectopic calcifications present in kidney biopsy. For kidney stones, the quantity of sample is sufficient to perform a significant analysis through classical FTIR. For ectopic calcifications, $\mu$FTIR can be inefficient in the case of $\mu$calcification in the tissue when their size is less than 10 $\mu$m. For such samples, Optical PhotoThermal IR (OPT-IR) spectroscopy may constitute a way to overcome this experimental difficulty through the acquisition of IR spectrum with a spatial resolution close to 500 nm.To illustrate such opportunity, we first compare the IR spectrum acquired with a classical experimental set-up related to classical IR spectroscopy to IR spectrum collected with a OPT-IR one for different compounds namely calcium oxalate monohydrate, calcium oxalate dehydrate, calcium phosphate apatite and magnesium ammonium phosphate hexahydrate. Such comparison helps us to assess specificity of OPT-IR. Then, we consider several pathological calcifications associated to hyperoxaluria, adenine phosphoribosyltransferase (APRT) deficiency or the presence of Randall’s plaque. We will see that the nanometer spatial resolution constitutes a major advantage versus a micrometre one. Also, in the case of Randall’s plaque, we show that OPT-IR can determine the chemical composition of microscopic concretion without any kind of preparation. Such experimental fact is clearly a major advantage. Finally, we also extended this first investigation in nephrology by considering breast calcifications. In that case, if the number of chemical phases is quite low compared to the number of chemical phases identified in ectopic calcifications present in kidney (four instead of 24), the challenge is related to the possibility to distinguish between the different calcium phosphate namely amorphous carbonated calcium phosphate, CA and whitlockite.The complete set of data indicates the limitations and the advantages of OPT-IR spectroscopy

Encrusted Uropathy: A Comprehensive Overview—To the Bottom of the Crust

International audienceEncrusted uropathy is a rare subacute to chronic inflammatory disorder caused by infection with urease-producing bacteria, mainly Corynebacterium urealyticum. The disorder is characterized by urothelial deposition of struvite and carbonated apatite, resulting in encrustations and ulceronecrotic inflammation of the urothelium and surrounding tissues. Most commonly, encrusted uropathy is encountered in patients with predisposing conditions. The disease remains underdiagnosed. High urinary pH and negative conventional urine cultures should raise suspicion of the diagnosis. Prognosis is dependent on timely diagnosis and treatment installment, which consists of urological removal of encrustations in combination with urinary acidification and long-term antibiotic therapy

Feasibility of monitoring bone remodelling around loaded percutaneous tibial implants in guinea pigs by in vivo microfocus computed tomography (µCT)

Guinea pigs were selected as an animal model for studying bone remodelling around loaded percutaneous implants. The feasibility of monitoring bone remodelling in vivo by microfocus computed tomography was assessed experimentally. A microfocus computed tomography (mCT) protocol was developed to minimise the side effects (i.e. radionecrosis) while maintaining sufficient image quality to allow segmentation of the mCT slices for subsequent processing into finite element models. (c) 2001 Elsevier Science B.V. All rights reserved.status: publishe

Renal progression factors in young patients with tuberous sclerosis complex: a retrospective cohort study

BACKGROUND: Renal pathology in tuberous sclerosis complex (TSC) is characterized by the growth of angiomyolipoma and renal cysts, and in rare cases renal cell carcinoma. Other consequences of renal involvement in TSC, including hypertension, proteinuria, and hyperfiltration, are not well studied. We aimed to analyze the early manifestations of the renal TSC phenotype in a young TSC cohort and to explore common, modifiable risk factors. METHODS: In this retrospective cohort study, TSC patients attending the TSC clinics of two tertiary hospitals were included. Data on demographics, history, genotype, kidney function, hematuria, proteinuria, blood pressure, and renal imaging were collected. RESULTS: Eighty patients were included, with a median age of 0.8 years (0.0-63.0) at first presentation, and a median follow-up time of 10.2 (0.4-41.0) years. Mutation analysis was available in 64 patients (80%). Renal lesions (cysts or angiomyolipoma) were observed in 55/73 (75%). Thirty-two percent (19/60) were hypertensive, 8/51 (16%) had proteinuria, and 18/71 (25%) had hyperfiltration (median eGFR 154 ml/min/m2). Six (7.5%) patients had developed end stage renal disease at the last follow-up. No association was found between hyperfiltration, hypertension, or proteinuria and CKD ≥ 3. Cox regression showed a significant positive association between the presence of a renal intervention and CKD ≥ 3 (Hazard-Ratio 3.91, P < 0.05). CONCLUSIONS: Besides renal cysts and angiomyolipoma, the modifiable progression factors hypertension, proteinuria, and hyperfiltration occur frequently and early in TSC patients. This represents a preventive treatment target.status: publishe

In search of an efficient complexing agent for oxalates and phosphates : a quantum chemical study

Limiting gastrointestinal oxalate absorption is a promising approach to reduce urinary oxalate excretion in patients with idiopathic and enteric hyperoxaluria. Phosphate binders, that inhibit gastrointestinal absorption of dietary phosphate by the formation of easily excretable insoluble complexes, are commonly used as a treatment for hyperphosphatemia in patients with end-stage renal disease. Several of these commercially available phosphate binders also have affinity for oxalate. In this work, a series of metallic cations (Li+, Na+, Mg2+, Ca2+, Fe2+, Cu2+, Zn2+, Al3+, Fe3+ and La3+) is investigated on their binding affinity to phosphate and oxalate on one side and anionic species that could be used to administer the cationic species to the body on the other, e.g., acetate, carbonate, chloride, citrate, formate, hydroxide and sulphate. Through quantum chemical calculations, the aim is to understand the competition between the different complexes and propose possible new and more efficient phosphate and oxalate binders