[Nephropathy associated with monoclonal immunoglobulins: From clonal expansion B to renal toxicity of pathological immunoglobulins]. / Les néphropathies associées aux immunoglobulines monoclonales : de l'expansion clonale B à la toxicité rénale des immunoglobulines pathologiques.

Germinal center regulation pathways are often involved in lymphomagenesis and myelomagenesis. Most of the lymphomas (and multiple myeloma) derive from post-germinal center B-cells that have undergone somatic hypermutation and class switch recombination. Hence, B-cell clonal expansion can be responsible for the presence of a monoclonal component (immunoglobulin) of variable titer which, owing to physicochemical properties, can provoke pathologically defined entities of diseases. These diseases can affect any functional part of the kidney, by multiple mechanisms, either well known or not. The presence of renal deposition is influenced by germinal gene involved, immunoglobulin primary structure, post-translational modifications and microenvironmental interactions. The two ways immunoglobulin can cause kidney toxicity are (i) an excess of production (overcoming catabolism power by proximal tubule epithelial cells) with an excess of free light chains within the distal tubules and a subsequent risk of precipitation due to local physicochemical properties; (ii) by structural characteristics that predispose immunoglobulin to a renal disease (whatever their titer). The purpose of this manuscript is to review literature concerning the pathophysiology of renal toxicities of clonal immunoglobulin, from molecular B-cell expansion mechanisms to immunoglobulin renal toxicity.

[Nephrology in Sub-saharan Africa: Past, present, future]. / Néphrologie en Afrique subsaharienne : passé, présent, futur.

Nephrology was a relatively poorly known specialty in sub-Saharan Africa until the early 1980s, because of low awareness and lack of access to diagnosis and renal replacement therapies. Nephrology has seen progress on the continent despite an unfavourable economic and geopolitical environment. With a prevalence of fewer than five nephrologists per million inhabitants, the training of nephrologists, now carried out on the continent, allowed to have more than 200 specialists trained in the last decade in French-speaking sub-Saharan Africa. Clinical and basic research is developing with quality work published from the continent in major international journals. The population receiving haemodialysis remains small, between 0 and 200 per million inhabitants. Kidney transplantation, with a prevalence between 0 and 5 per million inhabitants, is only well structured in South Africa. In this context of scarce resources, a strategy based on the prevention of non-communicable diseases in general, and chronic kidney disease in particular, should be prioritised.

Surgical management of secondary hyperparathyroidism in dialysis patients in Senegal.

Secondary hyperparathyroidism (SHPT) is a common complication of end-stage renal disease. Surgical management occurs in severe forms and/or unresponsive medical treatment. The aim of this study was to outline the indications of parathyroidectomy and its evolution after surgical approach. It was a five-year multicenter backward study in Otorhinolaryngology Department of Fann Hospital and four dialysis centers in Dakar. We include all patients with SHPT who underwent surgery. Preoperative clinical and paraclinical parameters, clinical-biological evolution, and histology findings of the resected parathyroid specimen were collected. Out of 58 patients with hyperparathyroidism, 18 patients required parathyroidectomy, corresponding to a prevalence of 31%. Mean age of patients was 46.6 ± 15.29 years and sex ratio 0.61. Mean duration on dialysis was 44.4 ± 30 months. Ten patients (55.56%) had bone pain and nine patients (50%) had joint pain. Mean serum calcium was 97.27 ± 8.66 mg/L. Mean blood phosphorus levels were 40.47 ± 9.99 mg/L. Mean iPTH rate was 1493.22 ± 1014.93 ng/mL, with a maximum of 5000 ng/mL (77N). Mean value of 25-OH Vitamin D was 32.89 ± 16.02 ng/mL. Parathyroidectomy was indicated after failure of medical treatment with persistence of a serum intact parathyroid hormone concentration above 800 µg/mL in all patients. Subtotal parathyroidectomy (7/8) was performed in 11 patients (61.1%). Two patients (11.11%) benefited from a selective parathyroidectomy (3/4). Evolution was favorable for 13 patients, corresponding to a success rate of 72.2%. It was unfavorable in five patients including one patient with hypoparathyroidism and four patients with recurrent hyperparathyroidism. Surgery for patients with renal hyperparathyroidism in the era of calcimimetics continues to play an important role in selected patients and achieves efficient control of hyperparathyroidism in developing countries.

Evaluation of blood pressure profile in chronic hemodialysis patients using two measurement methods: Home blood pressure measurement and conventional measurement.

The monitoring of hypertension (HTN) in dialysis is often delicate with potentially false measurements due to the white coat effect on the one hand and masked HTN (M-HTN) on the other hand. In this population, there is much controversy over the ideal moment for taking blood pressure (BP) and the target values. An answer to these questions is given by home BP measurement that can detect white coat HTN (WC-HTN) and M-HTN. The aim of this study was to determine the respective prevalence of permanent HTN (P-HTN), WC-HTN, M-HTN, and permanently normotensive (P-NTN) in this population and to analyze the risk factors of M-HTN and WC-HTN in hemodialysis (HD) centers in sub-Saharan Africa. This was a multicenter, descriptive, and analytical cross-sectional study conducted over a period of one month and 23 days. Data collection was performed using a home BP measurement form, conventional BP measurement form, and clinical and laboratory data collection form. The study included all patients who could take their BP at home using an electronic BP machine and record results on the BP forms. All analyses were performed using the Sphinx plus software version 5. The significance level for all statistical tests was set at 5%. The mean age of patients was 45.57 years ± 14.11, with a sex ratio of 1.42. The mean duration in dialysis was 57.96 months ± 34.86. Adherence to the home BP measurement was 100% in 71.7%. P-NTN patients were 15.2% (7 patients), WC-HTN patients were 13% (6 patients), M-HTN patients were 17.5% (8 patients), and P-HTN patients were 54.3% (25 patients). A statistically significant association was observed between WC-HTN and age (P = 0.01). In this work, we noted an important proportion of M-HTN and WC-HTN. This result confirms the need for home BP measurement in the follow-up of BP in HD patients.

Prevalence and risk factors of chronic kidney disease in an african semi-urban area: Results from a cross-sectional survey in Gueoul, Senegal.

Chronic kidney disease (CKD) is a public health priority worldwide; however, its prevalence and incidence are difficult to assess. In Africa, few studies have been conducted on the prevalence of CKD. This study sought to describe the epidemiological characteristics and profile of CKD, as well as the related risk factors in Guéoul, a semi-urban zone in Senegal. An observational, cross-sectional, and descriptive study was conducted in Guéoul city in Senegal from November 1, 2012, to December 10, 2012, according to the WHO STEPS approach. People older than 35 years living in Guéoul city were included in the study. Cardiovascular and renal disease risk factor screening was conducted for this population. Data were analyzed using the 3.5.1 version of Epi Info software. The significance level was a P <0.05. One thousand four hundred and eleven participants with a mean age of 48 ± 12.68 years and a sex ratio of 0.34 were included in the study (359 men/1052 women). The prevalence of renal disease was 36.5%. Sixty-eight people showed proteinuria greater than two cross with urinary dipsticks. Two hundred and six people had a glomerular filtration rate <60 mL/min, and among them, 201 were in stage III, two in stage IV, and three in stage V according to the modification of diet in renal disease formula. Ninety-eight participants had morphological abnormalities. Cardiovascular risk factors found among participants with renal disease were obesity (25.2%), hypertension (55.5%), diabetes (2.3%), and renal and metabolic syndrome (32.43%). Those that statistically significantly correlated with renal disease were obesity (P = 0.0001), hypertension (P = 0.0001), and diabetes (P = 0.021). This study assessed the extent of renal disease in the population of Guéoul city. Being aware of the prevalence of CKD in the general population of Senegal is mandatory for defining appropriate strategies for the management of these risk factors and progression of renal diseases.

Scleroderma renal crisis in tropical region: two senegalese cases.

Scleroderma renal crisis (SRC) is defined as the new onset of accelerated arterial hypertension and /or rapidly progressive oliguric renal failure during the course of systemic sclerosis. It is a rare but life-threatening complication. This formerly serious complication has got a considerable brighter outlook since the introduction of angiotensin converting enzyme inhibitors (ACE) however the mortality is still remaining high. We report two cases of SRC which to our knowledge are the firsts described in Dakar. They were two women aged 45 and 32 years, one of them was previously following for systemic sclerosis. Both of them had malignant hypertension associated with rapidly progressive renal failure, the other was put under corticosteroid therapy four months before SRC occurrence. The histological and laboratory finding showed thrombotic microangiopathy. The height blood pressure returned to normal value after treatment with ACE inhibitors. The final outcome was undesirable with the death of one after two months due to the hemodialysis discontinuation and persistence of renal failure in the other.

Hemophagocytic Syndrome, an Uncommon Complication of Microscopic Polyangitis: A Case Report From Senegal.

INTRODUCTION: We reported a case of hemophagocytic syndrome complicating microscopic polyangitis presented by crescentic glomerulonephritis. CASE PRESENTATION: A 22-year-old female patient originated from Dakar, Senegal presented with nephrotic syndrome and rapidly progressive glomerulonephritis. On physical examination, we noticed hyperchromic diffuse punctilious purpura skin lesions predominant on the trunk, the neck and the upper thigh. Immunology investigations revealed strongly positive anti SSA/Ro and anti-SSB. Anti-neutrophil cytoplasmic antibodies had positive results with a peri-nuclear type fluorescence, specific to myeloperoxidase. In optic microscopy, renal biopsy showed a crescentic glomerulonephritis with circumferential cellular and fibrous proliferation affecting 85% of glomeruli. The diagnosis of microscopic polyangitis with renal and skin involvement was retained. The patient received methylprednisolone and cyclophosphamide 700 mg/m(2) every 15 days for the first 3 pulses and every 21 days thereafter. After the 5(th) month, she developed obnubilation, fever and central pancytopenia. Bone marrow aspiration was performed, which showed medullary invasion by macrophages with signs of hemophagocytosis. Diagnosis of hemophagocytic syndrome complicating a microscopic polyangitis was retained and methylprednisolone pulses started. The patient was under hemodialysis after follow-up of about 9 months with stable clinical state. CONCLUSIONS: The occurrence of SAM in pauci-autoimmune vasculitis is rarely described, particularly in Africa. Our case is an illustration of the reality of this association.

Erectile dysfunction in chronic hemodialysis patients in dakar: a cross-sectional study in 2012.

BACKGROUND: Patients with chronic kidney disease (CKD) experience multiple complications including erectile dysfunction (ED). It involves more than 50% of patients on dialysis or transplant. In Africa, the true extent of ED in CKD is unknown although some studies have been done in this regard. OBJECTIVES: This study aimed to determine the prevalence and identify risk factors of ED in patients on hemodialysis. PATIENTS AND METHODS: This cross-sectional multicenter study was conducted from January 2, 2012 through April 30, 2012 in four hemodialysis centers in Dakar. We included all patients on chronic hemodialysis who aged ≥ 18 years old and freely consented to participate in the study. Sociodemographic, clinical, and hemodialysis data were collected through a questionnaire. Erectile function was assessed by a short version of International Index of Erectile Function (IIEF-5). RESULTS: Among a target of 80 patients, 73 met the inclusion criteria and were included in this study. Mean dialysis vintage was 27.3 months (range, 1-156). Their mean age was 53.81 ± 12.52 years, with a higher proportion of age group of 50 to 69 years old. Fifty-six patients were married (37 monogamous and 19 polygamous) and six were singles. Overall prevalence of ED was 84.9% and it was severe in 14 patients (19.2%). Hypertension and diabetes were the most frequent etiologies and antihypertensive treatment was used in 95.5%. The main factors associated with ED were age > 50 years old and polygamy. CONCLUSIONS: ED is a common problem among patients on hemodialysis in Dakar with a high prevalence. Aging and diabetes represent most common causes. More efforts are needed for its early detection, prevention, and multidisciplinary management.