Decreasing incidence of renal cortical necrosis in patients with acute renal failure in developing countries: a single-centre experience of 22 years from Eastern India.

BACKGROUND: Renal cortical necrosis (RCN) accounts for 2% of all cases of acute renal failure (ARF) in adults and 15-20% of ARF during the third trimester of pregnancy in developed nations. However, RCN incidence is higher in developing countries ranging from 6-7% of all cases of acute renal failure. The present study describes changing trends in the clinical spectrum of RCN in patients with ARF in Eastern India. METHODS: Patients with ARF suspected to have RCN on clinical grounds underwent percutaneous renal biopsy. Patients showing cortical necrosis on histology were included in the present study. Diffuse and patchy cortical necrosis was classified based on standard histological criteria. The patients with cortical necrosis were studied over a period of 22 years; from July 1984 to December 2005. The results of our observation were compared with respect to etiology, incidence, prognosis and outcome of renal cortical necrosis in two study periods; namely, 1984-1994 and 1995-2005. RESULTS: The incidence of RCN was 3.12% of all cases of ARF of diverse etiology. RCN was observed in 57 patients; obstetric 32 (56.2%); non-obstetric 25 (43.8%). Diffuse cortical necrosis was the dominant lesion in 41 (71.9%) patients and the remaining 16 (28%) patients had patchy cortical necrosis. The overall incidence of RCN in obstetric ARF was 15.2%; the incidence being higher (11.9%) in the post-abortal group in comparison to 3.3% in late pregnancy. RCN had occurred complicating abruptio placentae, puerperal sepsis and postpartum haemorrhage (PPH) in late pregnancy, while septic abortion was the sole cause of RCN in early pregnancy. Haemolytic uraemic syndrome (HUS) was the major (31.5%) cause of RCN in the non-obstetric group and miscellaneous factors were responsible in seven (12.3%) patients. Partial recovery of renal function was observed in 11 (19.2%), and 16 (28%) patients had progressed to ESRD. The incidence of RCN decreased from 6.7% in 1984-1994 to 1.6% in 1995-2005 of total ARF cases. RCN following obstetrical complication decreased significantly; 4.7% in the 1990s to 0.5% of the total ARF cases, in the 2000s. The mortality decreased to 19% in 1995-2005 from the initial high mortality of 72% in 1984-1994. The renal prognosis improved as a result of the decreased mortality of patients. CONCLUSION: We observed a decreasing trend in the incidence of RCN in patients with ARF in recent years, which is associated with increased patient survival and better renal prognosis. This improvement was mainly due to declining incidence and severity of RCN in obstetrical ARF.     

Urinary doubly refractile lipid bodies in nonglomerular renal diseases

Urinary doubly refractile lipid bodies (DRLB) are a characteristic finding in patients with glomerular renal diseases causing heavy proteinuria. DRLB are felt to be an uncommon finding in glomerular diseases without heavy proteinuria, and a rare finding in nonglomerular renal diseases. In order to determine whether DRLB are found in nonglomerular renal diseases, we reviewed the medical records of all patients who had urinalyses performed in our laboratory from February 1975 to June 1983. Three hundred sixty one patients demonstrated less than or equal to +2 proteinuria, and at least two DRLB. Of these, 290 were identified as having a single renal diagnosis. One hundred forty eight patients (51%) had a variety of acute and chronic glomerular diseases, and 125 patients (43.2%) had nonglomerular renal diseases, including acute tubular necrosis (ATN), prerenal azotemia, chronic interstitial nephritis, polycystic kidney disease, acute interstitial nephritis, renal neoplasia, and acute myeloma kidney. Ten patients had transient proteinuria associated with acute illness, and seven patients had no renal disease at all. Only two patients with nonglomerular renal disease had more than five DRLB per 20 high power microscopic fields. The frequency of DRLB in patients with nonglomerular renal diseases was: chronic interstitial nephritis, 26%; polycystic kidney disease, 38%; prerenal azotemia, 20%; ATN, 15%; and acute interstitial nephritis, 33%. These data suggest that at lower levels of proteinuria, DRLB are found frequently in nonglomerular renal diseases, and that DRLB do not differentiate glomerular from nonglomerular renal diseases unless more than five DRLB are found on urinary sediment examination.     

Spectrum of renal diseases in the elderly: Single center experience from a developing country

From November 1998 to March 2000, two hundredpatients over the age of 60 years (Elderly)with clinical renal disease were studied. 144patients were between ages of 60–69 years, 46between 70–79 years and 10 were above 80 years.The elderly patients (Male 165; Female 35) withrenal disease constituted 11% (200/1816) ofthe total nephrology consultation during thestudy period. The clinical presentationincluded chronic renal failure (42.5%); acuterenal failure (28%); nephrotic syndrome(14.5%); acute glomerulonephritis (7.5%);renal vascular disease (5%) and renal cysticdisease (2.5%). Diabetic nephropathy,obstructive uropathy and hypertensivenephrosclerosis were the major causes of CRF,accounting for 80% of total CRF in theelderly. Chronic glomerulonephritis and chronicpyelonephritis (CPN) were less common andetiology of CRF was uncertain in 5.9% ofcases. However, diabetic nephropathy was thecommonest (49.4%) cause of chronic renalfailure. We did not see a single case ofischemic nephropathy causing CRF in the presentstudy. Prerenal ARF, obstructive uropathy andsepsis were contributing factors for ARF in82% of the cases. Volume depletion due togastrointestinal fluid loss and urinary tractobstruction on account of enlarged prostatewere the leading causes of ARF in 20 (35.7%)and 8 (14.3%) cases respectively. Sepsis withor without multiorgan failure was the major(46.7%:) cause of mortality in patients withARF and overall mortality was 26.8%. Thecommonest (31%) cause of nephrotic syndromewas the idiopathic membranous nephropathy.Diabetic nephropathy related to type-2 diabetesmellitus was the second most common (24.1%)cause of nephrotic syndrome. Diffuseendocapillary proliferative GN of postinfectious etiology was the commonest (73.3%)type of acute GN in our elderly patients. Renalcystic diseases were noted in 5 (ADPKD 3;Simple cyst-2) patients. Thus, overall spectrumof renal disease in our elderly patients issimilar to that of developed nations except intwo ways: (i) Endocapillary proliferative GN ofpost infectious origin was the commonest typeof acute GN and (ii) Rarity or absence ofischemic nephropathy and atherosclerotic renalartery occlusive disease.     

Glomerulonephritis causing acute renal failure during the course of bacterial infections. Histological varieties,potential pathogenetic pathways and treatment

To illustrate diagnostic approaches, potential pathogenetic differences, epidemiological implications and therapeutic dilemmas posed by glomerulonephritis (GN) with acute renal failure (ARF) complicating bacterial infections, we analyzed the course of four male patients, aged 53–71 years, who developed GN and ARF following bacterial infections. The first two patients developed GN with immunoglobulin A (IgA) deposits after infections with hospital-acquired methicillin resistant Staphylococcus aureus (MRSA). Clinical, serologic and histological features, classification of GN and treatment differed between the two patients. In the first patient, serological features (transient hypocomplementemia, normal serum protein electrophoresis) and histological findings were consistent with typical post-infectious GN. Treatment with antibiotics alone resulted in normalization of the renal function despite the severity of ARF, which required temporary hemodialysis. In the second patient, serological features (normal serum complement, polyclonal elevation of gamma globulins) and histological picture of the kidneys were characteristic of IgA nephropathy with fibrocellular crescents, and skin histology was consistent with vasculitis. Cyclophosphamide and corticosteroids were added to the antibiotics, with partial improvement of the renal failure. The third patient developed simultaneous acute rheumatic fever and post-streptococcal GN causing severe ARF requiring hemodialysis. Complete recovery of ARF and migratory polyarthritis followed initiation of corticosteroids. The fourth patient developed ARF and cerebral vasculitis following a prolonged course of Streptococcus mutans endocarditis with delayed diagnosis. He also developed multiple serological abnormalities including elevated titers of antineutrophil cytoplasmic antibodies (ANCA), antinuclear antibodies (ANA), anti-phospholipid antibodies, rheumatoid factor, and modest hypocomplementemia. Kidney biopsy revealed ANCA-mediated focal GN with 10% crescents and acute interstitial nephritis. Treatment with cyclophosphamide plus corticosteroids, but not with antibiotics alone, resulted in resolution of both the ARF and the features of cerebral vasculitis. GN following bacterial infections may have various pathogenetic mechanisms, presents complex diagnostic challenges, may be preventable in the case of hospital-acquired MRSA, and, in addition to antibiotics, may require immunosuppressive therapy in carefully selected and monitored cases.     

Pathology of renal diseases in the tropics

Renal diseases unique to the tropics are those that occur in association with infectious diseases including dengue hemorrhagic fever, typhoid fever, shigellosis, leptospirosis, lepromatous leprosy, malaria, opisthorchiasis, and schistosomiasis. These renal complications can be classified on the basis of their clinical and pathologic characteristics into acute transient reversible glomerulonephritis, chronic progressive irreversible glomerulonephritis, amyloidosis, and acute renal failure (ARF) resulting from acute tubular necrosis, acute tubulointerstitial nephritis, and thrombotic microangiopathy. Certain primary glomerular diseases including immunoglobulin (Ig) M nephropathy and focal segmental and global glomerulosclerosis are prevalent in some tropical countries. Renal complications of venomous snakebites also are common in the tropics. This article discusses and summarizes important works in the literature in respect to the clinical syndromes, pathologic features, and pathogenesis of tropical renal diseases both in humans and experimental animal models.     

慢性肾脏病基础上的急性肾功能衰竭

目的 了解慢性肾脏病基础上急性肾功能衰竭(A／C)的发病情况及临床和病理特点。方法 对我科12年间(1990年1月至2001年1月)经肾活检证实的此种病例进行原因、与基础肾脏病关系、预后影响因素及转归的分析。结果 104例符合选择标准,占急性肾功能衰竭(ARF)病例数的35．5％。慢性肾脏病发生ARF的常见原因为药物引起的急性间质性或间质肾小管病变,狼疮肾炎(LN)活动以及肾病综合征伴特发性ARF。104例患者中,共有39例ARF与药物相关。关于基础肾脏病,ARF原因为病变活动的患者以LN为主,特发性ARF者以微小病变性肾病(MCD)为主,而ARF原因为恶性高血压的患者则以IgA肾病与硬化性肾小球肾炎多见。在104例患者中,有2例死亡;39例需要血液透析治疗,治疗后有23例脱离透析。出院时,48例患者血肌酐恢复到正常水平。多元Logistic回归分析提示,高血压、接受透析治疗、高血肌酐水平预示肾功能不易恢复。在有明确院外诊断的21例患者中,有15例被诊为“慢性肾功能衰竭”,占71．4％。结论 慢性肾脏病基础上发生的ARF并不少见。警惕药物引起的肾损害(尤其对于老年人)、控制结缔组织病的活动以及积极控制血压和维持循环血量对于预防肾脏病患者发生ARF十分重要。经过适当治疗后,大部分患者的肾功能有所改善。因此,早期正确的诊断和治疗对A／C的预后有重要的意义。     

Frequency of renal diseases and clinical indication for renal biopsy in children (Report of the Italian National Registry of Renal Biopsies in Children)

Background. Children's renal biopsy data were gathered for 3 consecutive years (1992-1994) by the Group of Renal Immunopathology of the Italian Society of Pediatric Nephrology, which opened a paediatric section of the Italian Registry of Renal Biopsies. Materials. The Registry recorded the histological diagnosis and the clinical data at renal biopsy of 432 children ⩽15 years old (mean age 8.96±3.7 years). Results. The most common glomerulonephritis (GN) at renal biopsy was idiopathic IgAGN (18.8%) and the most frequent secondary GN was Henoch-Schonlein purpura (HSP) nephritis (11.6%). Minimal-change disease (MCD) accounted for 11.6%, focal and segmental sclerosis (FSG) 8.5%, mesangial proliferative GN (MPGN) 9.5%, membranoproliferative GN 5.5%, and thin-membrane disease 5%. Lupus nephritis was diagnosed in 5% and Alport's GN in 3.9% of the cases. The annual incidence of primary GN in Italian children was 11.1 cases per million children population (p.m.c.p.), IgAN accounting for 3.1 cases, MCD 2.3, and HSP nephritis 1.9 cases p.m.c.p. respectively. Italian children underwent renal biopsy because of isolated microscopic haematuria in 19.3% of the cases, non-nephrotic proteinuria with or without microscopic haematuria in 31.2%, and nephrotic-range proteinuria in 34.2%, less frequently (15.3%) because of acute or chronic renal failure. Children with persistent isolated microscopic haematuria had most frequently IgAN (34.9%) or thin-membrane disease (25.3%), while those with non-nephrotic proteinuria had IgAN (30.4%) and HSP nephritis (23%). In cases with nephrotic proteinuria renal biopsy showed MCD in 34.5% of the cases, FSG in 16.9%, and MPGN in 12.2%. When renal biopsy was performed in chronic renal failure chronic interstitial renal disease was detected in 62.5% of the cases. Conclusions. This National Registry provides data on the indications for performing renal biopsy in Italian children and on the frequency and annual incidence of histological lesions detected. IgAN, primary or related to HSP, was the most common nephritis in Italian children undergoing renal biopsy.     

Acute renal failure in Falciparum malaria--increasing prevalence in some areas of India--a need for awareness

Twenty-six cases (4.8%) from a total of 540 patients with acuterenal failure (ARF) of diverse aetiology had ARF in associationwith falciparum malaria. Their ages ranged from 15 to 85 years(mean 31.2). Urinary sediment abnormalities and proteinuria(less than 1 g/24 h) were observed in 15 (57.7%) cases. Theprobable underlying factors leading to ARF were: volume depletion17 (65.3%), intravascular haemolysis 8 (30.8%), hyperparasitaemia8 (30.8%), cholestatic jaundice 6 (23%), and hypotension 5 (19.2%).Dialysis therapy was required in 15 patients (57.7%) as theyhad severe renal failure, and the remaining 11 patients improvedwith supportive measures. All patients received antimalarialtherapy. The clinical course of ARF was consistent with acutetubular necrosis in 20 patients. Six cases were subjected topercutaneous renal biopsy. One patient showed histological featuresof necrotizing glomerulonephritis along with acute tubulointerstitialnephritis. The biopsies in the other five patients showed featuresof acute tubular necrosis in three, and acute interstitial oedemawith patchy tubular necrosis in two. The mortality rate was30.8%. Thus falciparum malaria, which has been an importantcause of ARF in certain highly endemic zones of India, is showingan increasing prevalence in other parts such as Eastern UttarPradesh due to an imbalance between the increasing populationand inadequate sanitary facilities, which further worsen duringfloods.     

Acute renal failure in children with idiopathic nephrotic syndrome

Acute renal failure (ARF) is an uncommon but alarming complication of idiopathic nephrotic syndrome. The renal failure could be secondary to causes evident from the history and evaluation, such as severe intravascular volume depletion, acute tubular necrosis, allergic interstitial nephritis, bilateral renal vein thrombosis, acute pyelonephritis, or rapid progression of the original glomerular disease. It may be termed idiopathic if the underlying cause is undetermined. We present three children with idiopathic nephrotic syndrome who were admitted with acute renal failure. One case was due to drug-induced allergic interstitial nephritis. The other two were idiopathic in nature. Improvement in renal function occurred in the three patients over a variable period of 10 days to 4 weeks. After careful exclusion of well-known causes of acute renal failure, idiopathic acute renal failure (IARF) should be considered as a diagnostic possibility in these patients. The exact pathophysiology of IARF is not understood. Possible proposed explanations include interstitial edema, tubular obstruction, altered glomerular permeability, and unrecognized hypovolemia.     

Fatal renal and hepatic failure following silver nitrate instillation for treatment of chyluria.

Sir, Toxic acute tubular necrosis (ATN) accounts for the largestnumber of cases of acute renal failure (ARF) after ischaemicATN. We discuss here a case of fulminant hepatic and renal failurefollowing instillation of silver nitrate. This patient underwentsilver nitrate instillation in the renal pelvis     

Acute renal failure in man: pathogenesis in light of new morphological data

The pathogenesis of acute renal failure (ARF) in such common conditions as acute tubular necrosis, acute interstitial nephritis, and primary graft anuria (ischemic transplant ARF) is poorly understood. Animal models may not exactly mimic the situation in man and thus human morphologic studies are of particular importance. Non-replacement of individual sloughed tubular cells and simplification of the brush border and basolateral infoldings of tubular cells are prominent morphologic changes which correlate with the presence of renal failure. It is possible that the initial injury inhibits cell membrane synthesis, thus interfering with proximal tubular sodium reabsorption with resulting activation of the renin angiotensin system and afferent arteriolar vasoconstriction. Tubular backleak, tubular obstruction by casts and debris, and decreased glomerular ultrafiltration coefficient may also play a role. Although poorly studied until now, the renal failure in primary graft anuria may have a completely different pathogenesis from that in acute tubular necrosis and acute interstitial nephritis. Cyclosporine nephrotoxicity is an important component of primary graft anuria, as seen in many transplant centers in the 1980's.     

Spectrum of renal failure in elderly patients

This prospective study was undertaken to study the spectrum of renal failure and the outcome in elderly patients. Patients included in the study group were elderly (age > 60 years) who either attended outpatient renal clinic and or were hospitalized. Renal failure was classified as acute renal failure (ARF), rapidly progressive renal failure (RPRF) and chronic renal failure (CRF). A total of 4255 elderly patients were seen, of these 236 (5.5%) had renal failure. Mean age was 65.1 ± 4.2 years (60–86 years). CRF was the commonest, seen in 137 (58.1%) followed by ARF 69 (29.2%) and RPRF in 30 (12.7%) patients. Diabetic nephropathy was the commonest cause of CRF, seen in 58.4% followed by chronic interstitial nephritis in 9.5% and chronic glomerulonephritis in 8.7% of patients. Of 137 patients 53 (38.7%) presented in end stage renal disease (ESRD). Of these 41 (77.3%) were initiated on maintenance hemodialysis and 12 (22.6%) on continuous ambulatory peritoneal dialysis. Only 15 patients were on dialytic support at the end of 1 year. Sepsis contributed to ARF in 75.4% of cases. Forty of 69 patients (57.9%) needed dialytic support. Forty (57.9%) were critically ill, defined as presence of two or more organ system failures (excluding renal failure). Forty two patients (60.9%) died patients. Acute interstitial nephritis (AIN) was the commonest cause of RPRF seen in 10 (33.3%) patients followed by vasculitis in 7 (23.3%). Myeloma cast nephropathy contributed towards RPRF in 20% of patients. Of 30 patients, 10 (33.3%) reached ESRD at end of 3 months of follow up, 4 (13.3%) died due to sepsis. Only 2 showed complete recovery while 14 (46.6%) had partial improvement. AIN patients had a relatively better outcome.     

Changing trends in pediatric renal biopsies: analysis of pediatric renal biopsies in national nephrology registry data

Renal biopsy is the gold standard method for determining the diagnosis, treatment, and prognosis in children with renal disease. This study aims to evaluate the histopathological features of pediatric renal biopsies obtained from the national nephrology registry in the last two decades. Data recorded in the Turkish Society of Nephrology Registry System (TSNRS) in 1991 as well as in between 2001 and 2010 were analyzed. A total of 3892 biopsies were recorded; with the least number in 1991 (total 103 biopsies from 17 centers) and the highest number in 2008 (total 654 biopsies from 23 centers). Glomerular diseases constituted the main group in the registry (62.64%), followed by systemic diseases (20.06%). Focal and segmental glomerulosclerosis (FSGS) and Henoch–Schönlein purpura (HSP) nephritis (IgA vasculitis) were the most common glomerular and systemic diseases, respectively. Overall prevalence of renal amyloidosis and membranous nephropathy (MN) was quite low (1.87% and 1.56%, respectively) in all periods. Compared to 1991, there was an increasing trend in the frequencies of certain disorders including hemolytic uremic syndrome (HUS), IgA nephropathy, and HSP nephritis; and there was a decrease in acute proliferative glomerulonephritis (GN) in 2008. As well as demonstrating the etiologies of renal diseases which can only be identified by renal biopsies, this study provides important information regarding the changing patterns of histopathological findings due to better management of pediatric renal diseases over the years in Turkey.     

Snakebite induced acute interstitial nephritis: report of a rare entity

Snakebite induced acute renal failure continues to occur in many tropical areas of the world. Renal histological lesions other than acute tubular necrosis and acute cortical necrosis as the cause of acute renal failure are rare. Only 3 cases of acute interstitial nephritis in patients with snakebite induced acute renal failure have been previously reported. We report a patient with acute renal failure following viperine snakebite due to acute interstitial nephritis. After a prolonged oliguric phase, there was complete recovery of renal function without institution of steroids. Interstitial nephritis may result from a hypersensitivity reaction to some component of the snake venom.     

Histological features of acute tubular necrosis in native kidneys and long-term renal function

There are few studies on the relationship between the morphology of acute tubular necrosis (ATN) in native kidneys and late functional recovery. Eighteen patients with acute renal failure (ARF) who had undergone renal biopsy were studied. All had the histological diagnosis of ATN and were followed for at least six months. Clinical characteristics of ARF were analyzed, and histological features were semi-quantitatively evaluated (tubular atrophy, interstitial inflammatory infiltrate, interstitial fibrosis, and ATN). According to the maximal GFR achieved during the follow-up, patients were divided into two groups: complete recovery (GFR >or= 90 mL/min/1.73 m(2)) and partial recovery (GFR < 90 mL/min/1.73 m(2)). Only 39% of the patients achieved complete recovery. Patients with partial recovery achieved their maximal GFR (63 +/- 9 mL/min/1.73 m(2)) 37 +/- 14 months after ARF, a period of time similar to those patients with complete recovery (i.e., 54 +/- 22 months). Patients with partial recovery had more severe ARF: oliguria was more frequent (90 versus 17%, p < 0.01), and they had higher peak creatinine (13.85 +/- 1.12 versus 8.95 +/- 1.30 mg/dL, p = 0.01), and longer hospitalization (45 +/- 7 versus 20 +/- 4 days, p = 0.03). No single histological parameter was associated with partial recovery, but the sum of all was when expressed as an injury index [4.00 (2.73-5.45) versus 2.00 (1.25-3.31), p < 0.05]. In conclusion, among patients with atypical ATN course, those with more severe ARF and tubule-interstitial lesions are more prone to partial recovery.     

Analgesic and non-steroidal anti-inflammatory drug-associated acute renal failure: a prospective collaborative study

During a one-year period analgesic and non-steroidal anti-inflammatory drug-(NSAID) associated acute renal failure (ARF) was recorded in 147 of 398 patients registered in 58 nephrology units. This figure represented 36.9% of drug-associated ARF, and 6.8% of total patients with ARF hospitalized during the same period. Drugs involved were primarily glafenin (79), NSAID (62), paracetamol (5) and phenacetin (1 case). Hypersensitivity reactions were documented in 32 patients. Acute tubular necrosis was found in 20, and interstitial nephritis (AIN) in 9 of 34 biopsied patients. All patients in the glafenin group and 71.4% in the NSAID group recovered fully or regained previous renal function (p less than 0.01). Permanent renal damage (9.5% of total cases) was more frequent in patients with AIN than in those with other types of ARF (p less than 0.001). Preventive measures should be especially directed to older patients receiving NSAID, by avoiding the combined use of drugs potentiating their action and by correcting any predisposing factor to ARF.     

Acute renal failure in chronic kidney disease--clinical and pathological analysis of 104 cases

BACKGROUND: Acute renal failure in chronic kidney disease (A/C) constitutes an important part of acute renal failure (ARF), but until now there has been no research focusing on this entity. PATIENTS AND METHODS: Clinical data were collected from all patients diagnosed as A/C by clinical materials and renal biopsy over a 12-year period (January 1990 - December 2001) in the renal department of a teaching hospital, and the incidence, etiology, pathological and clinical features of A/C, and factors predicting prognosis were studied. RESULTS: Altogether, 104 patients of A/C were identified, which accounted for 35.5% of biopsied acute renal failure cases during the same period. Drug-induced acute renal interstitial/tubular-interstitial disease, prerenal ARF and flare-up of lupus nephritis were the most common causes of ARF in A/C patients. More than one third of A/C were associated with drugs, which occurred more commonly in older patients. After an average hospitalization of 28.5 days, about 39 patients required dialysis, 23 patients became dialysis-independent. The mortality was 1.9%. Furthermore, serum creatinine (Scr) returned to normal level (< 133 micromol/l) in 46.2% of all patients; Scr decreased by 15%, yet not normal in 26.0%. Multivariate logistic regression analysis indicated that hypertension, requirement of dialysis therapy and high Scr level were independent predictors of poor renal outcome. CONCLUSION: A/C constitutes an important part of ARF, and drug-induced ARF is prominent in China. Because early diagnosis and correct treatment may obviously affect prognosis, enough attention should be paid to this entity.     

并发肾脏中等动脉受累的显微镜下型多血管炎的临床病理特点

目的：探讨并发肾脏中等动脉受累的显微镜下型多血管炎（MPA）的临床与病理特点。方法：对近两年在我院经肾脏病理确诊的MPA进行分析总结，并比较有无并发肾脏中等动脉受累病例的临床及病理特点。结果：32例MPA患者中7例并发中等动脉受累。25例无中等动脉受累者，均有新月体形成，其中新月体肾炎19例，局灶节段型坏死性肾小球肾炎9例；21例表现为急性囊肾功能衰竭（ARF），平均病程10周；治疗后8例完全缓解。7例并发中等动脉受累者，弓状动脉大分支节段性纤维素样坏死，肾小球缺血改变突出，但新月体病变轻，无1例新月体肾炎；6例表现为ARF，平均病程4周；治疗后5例完全缓解。两组比较，合并中等动脉受累者病程短（P＜0．05），发生ARF者达新月体肾炎者少（P＜0．01），经强化免疫抑制治疗后多可完全缓解（P＜0．05）。结论：MPA中约20％同时累及肾脏中等动脉，因中等动脉病变引起广泛肾缺血，故ARF起病急、进展快，及时治疗预后相对较好。     

Rifampicin-associated acute renal failure: pathophysiologic, immunologic, and clinical features

A 71-year-old woman was treated for a relapsing pulmonary tuberculosis with reinstitution of rifampicin after a medication-free interval of 2 years. After ingestion of the second dose, she developed severe hemolytic anemia and acute renal failure (ARF) necessitating dialysis. We demonstrated the presence in the patient's serum of rifampicin-dependent immunoglobulin G (IgG) and IgM antibodies, which caused red blood cell lysis through interaction with the I antigen on the erythrocyte surface. A review of the literature yielded 48 cases of rifampicin-associated renal failure. A subgroup of 37 patients could be distinguished, which, analogous to our case, suddenly developed ARF and frequently also developed hemolytic anemia and/or thrombocytopenia during intermittent or interrupted treatment. Regarding the pathogenesis of the ARF, renal biopsy consistently revealed tubular lesions. Although intravascular hemolysis with hemoglobinuria may play a role, it is not uniformly present. Our demonstration of an antibody with anti-I specificity provides a possible explanation. The I antigen is also expressed on tubular epithelium and may, therefore, be the target structure through which rifampicin-antibody complexes lead to tubular cell destruction. The other cases of rifampicin-associated ARF were unrelated to this subgroup: two cases of rapidly progressive glomerulonephritis, five cases of acute interstitial nephritis, and four cases of light chain proteinuria were recorded.     

Acute renal failure in the course of HIV infection: a single-institution retrospective study of ninety-two patients anad sixty renal biopsies.

BACKGROUND: Acute renal failure syndromes are frequently encountered in patients with human immunodeficiency virus (HIV) infection. Most reported cases of acute renal failure are related to acute tubular necrosis, but many other causes of renal failure have been described in these patients. METHODS: The present work is a single-institution retrospective study of 92 HIV-infected patients with acute or rapidly progressing renal failure. In 60 cases, a renal biopsy was performed. For each patient we analysed clinical and pathological data, as well as the short-term prognosis. RESULTS: Ten different causes of acute or rapidly progressing renal failure were documented: (i) haemolytic uraemic syndrome (32 patients); (ii) acute tubular necrosis either of ischaemic-toxic origin (18 patients) or due to rhabdomyolysis (six patients); (iii) obstructive renal failure which was either extrinsic (two patients), drug-induced (13 patients) or secondary to paraprotein precipitation (one patient); (iv) HIV-associated nephropathy (14 patients); (v) acute interstitial nephritis (two patients); (vi) various glomerulonephritis (four patients). In most cases, renal failure was severe (the mean creatinine clearance at entry was 12 ml/min). Most patients had a significant improvement in renal function with only symptomatic treatment. Eighteen per cent of the patients died within 2 months of the diagnosis of renal failure. Renal biopsy seems important for the diagnosis but also for the prognosis, at least in the cases of haemolytic-uraemic syndrome, HIV-associated nephropathy and drug-induced micro-obstructive renal failure. CONCLUSION: Vascular and glomerular diseases are frequent causes of acute or rapidly progressing renal failure in HIV-infected patients. Renal biopsy appears to be safe and useful for the diagnosis and the prognosis of the renal failure. High mortality rate is only observed in patients with ischaemic/toxic causes of acute renal failure.