You will be presented with the full text of a biomedical research paper. Please write an abstract for this paper. Your response should include the abstract and no additional text.

Paper text:
in patients with autosomal dominant polycystic kidney disease ( adpkd ) , urinary protein excretion is usually < 1  g every 24 hour , and renal function declines at a slow rate , i.e. , a 2.8 ml/(minute1.73  m / y ) decrease in glomerular filtration rate . in cases of nephrotic - ranged proteinuria and rapid aggravation of renal function , performing a renal biopsy is critical because the other glomerular diseases might be superimposed on adpkd .
we report on a patient with adpkd who presented with acutely aggravated renal dysfunction and nephrotic - ranged proteinuria .
the patient underwent laparoscopic renal biopsy and was properly treated according to the histologic diagnosis .
a woman 48 year of age visited our hospital for generalized edema and arthralgia in september 2002 .
she developed swelling in multiple hand joints , arthralgia , and generalized edema in july 2002 .
hematologic tests at a local clinic showed the following results : blood urea nitrogen levels , 44  mg / dl ; serum creatinine , 1.7  mg / dl ; and 24-hour urine protein , 5,960  mg / day .
physical examination showed that her blood pressure was 120/80  mmhg and pulse rate was 80  beats / minute .
g / l ; total leukocyte count , 4,780/l ; platelet count , 12510/l ; erythrocyte sedimentation rate 130  mm / hour , c - reactive protein , 0.3  mg / dl ; blood urea nitrogen , 59  mg / dl ; creatinine , 2.3  mg / dl ; albumin , 2.4  g / dl ; total cholesterol , 176  mg / dl ; and normal liver enzymes levels .
urinalysis showed 2 + albumin via the dipstick test , > 100 red blood cells , and 2029 leukocytes per high - power field via microscopy .
further investigations showed positive results for antinuclear antibody ( ana ; 1:320 , homogenous pattern ) , an anti - dsdna antibody titre of 857 iu / ml ( normal range , < 25  iu / ml ) , and complement c3 of 22  mg / dl ( 83177  mg / dl ) and < 5  mg / dl ( 1647  mg / dl ) , respectively .
the right and left kidneys were 18  cm and 19  cm in length , respectively , and the largest cyst was 6.2  cm in the left . computed tomography ( ct ) confirmed the ultrasound result and diagnosis of adpkd ( fig .
the patient 's history of arthritis , overt proteinuria , high anti - dsdna antibody titer , and positive ana results satisfied the systemic lupus erythematosus criteria .
her creatinine level , which was 1.7  mg / dl at 3 weeks before visiting our hospital , rapidly increased to 2.4  mg / dl ; therefore , we decided to perform a renal biopsy .
2 ) 20 glomeruli in the biopsy sample , of which five ( 25% ) exhibited global sclerosis ; one exhibited ( 5% )
segmental sclerosis ; and 13 exhibited ( 65% ) crescent formation . during immunofluorescence analysis ,
the glomeruli showed diffuse granular peripheral staining of immunoglobulin ( ig ) g , iga , c3 , and c1q .
the glomerular basement membrane was irregularly thick , and the epithelial foot processes showed marked effacement . collectively , these observations were consistent with those for diffuse proliferative lupus nephritis [ ln ; world health organization ( who ) class iv ] .
after the patient underwent empirical methylprednisolone pulse therapy , 1 g per day for 3 days , she was put on intravenous cyclophosphamide pulse therapy , 500 mg monthly , and oral corticosteroid therapy .
the cyclophosphamide pulse therapy continued for 8 months , i.e. , up to may 2003 , and the serum creatinine levels decreased to 1.5  mg / dl .
subsequently , an additional four cycles of cyclophosphamide pulse therapy were administered every 2 or 3 months ; because the proteinuria levels increased again , seven additional cycles were administered until may 2006 .
although , no elevation in autoantibody titers and extra - renal lupus manifestation was observed , the patient 's renal function gradually declined over the years ( fig .
, she developed uremic symptoms and orthopnea because of volume overload ; therefore , hemodialysis was started .
this is a rare case of ln proved in a patient with adpkd who presented with nephrotic - ranged proteinuria . to our knowledge
, this patient represents the first case wherein a biopsy was performed for an adpkd patient by using a laparoscopic procedure .
proteinuria is frequently detected in adpkd patients , but nephrotic - ranged proteinuria is unusual .
the presence of nephrotic - ranged proteinuria in adpkd has been reported in 21 cases among the english literatures so far .
various histologic subtypes that have been described in the literature are summarized in table 1 .
the two main diseases with regard to superimposition of adpkd are focal segmental glomerulosclerosis ( 5/21 , 23.8% ) and membranous nephropathy ( 4/21 , 19.0% ) .
ln is very rare in patients with adpkd , and this index case is the third reported case . as other secondary glomerular diseases might superimpose on adpkd , a biopsy should be considered when unusual manifestations such as nephrotic - ranged proteinuria are detected .
although renal biopsy is important , multiple bilateral cysts in adpkd are assumed to be a relative contraindication for percutaneous renal biopsy because of the presumed risk of complications and difficulties involved in obtaining tissue suitable for diagnosis .
d'cruz and colleagues   previously described a patient with adpkd biopsied by open surgical procedure and mentioned that nephrologists are reluctant to perform renal biopsy in patients with adpkd because this usually entails an open renal biopsy . in the literatures , among the 21 biopsied adpkd cases , only five cases were performed by percutaneous procedure ( table 1 ) .
a renal biopsy under direct vision may be preferred , and an open renal biopsy is performed in most cases of polycystic kidney disease that need a biopsy , , , , .
however , with advances in endoscopic instrumentation , the development in laparoscopic renal biopsy now provides a minimally invasive alternative to open renal biopsy , .
the laparoscopic approach to kidney biopsy offers many advantages , including sufficient diagnostic sample , minimal injury risk , hemostasis under direct vision , a smaller incision , and a short hospital stay , .
we performed the laparoscopic renal biopsy without complication and obtained tissue suitable for analysis . in summary ,
our case emphasizes the need to perform renal biopsy in patients with adpkd and nephrotic - ranged proteinuria for precise diagnosis and proper management .
the laparoscopic approach for kidney biopsy was found to be safe and reliable ; therefore , we suggest this method for diagnosis in similar cases .
a 48-year - old woman with autosomal dominant polycystic kidney disease ( adpkd ) presented with generalized edema and arthralgia . 
 she showed evidences of acute glomerulonephritis including nephrotic - ranged proteinuria . because her serologic test results were consistent with those for systemic lupus erythematosus ( sle ) , we performed laparoscopic renal biopsy that confirmed world health organization ( who ) class iv lupus nephritis . 
 she was treated with steroids and intravenous cyclophosphamide pulse therapy and eventually started hemodialysis 8 years after the lupus nephritis was diagnosed . to our knowledge , this is the first case wherein a patient with adpkd underwent a laparoscopic biopsy for diagnosing lupus nephritis .