Many clinicians feel compelled to perform renal biopsy, even in patients considered to be high risk. In reality, if a diagnosis is obviously LN and mandates aggressive immunosuppression, kidney biopsy is not necessary because it will not change the initial treatment approach. Similarly, if a patient presents with extrarenal manifestations that mandate aggressive immunotherapy, renal biopsy provides little value and creates undue risk because the patient should receive aggressive therapy in any case. Therefore, it is necessary to evaluate each patient individually to determine the need for and value of renal biopsy.
Although initial renal biopsy may be useful in some patients, the value of repeat biopsy is questionable. Some recommend repeat biopsy after treatment induction or during maintenance immunosuppressive therapy to assess treatment effectiveness. Others, however, favor repeat biopsy only when clinically indicated, such as in cases of persistent or worsening proteinuria or hematuria, increasing creatinine levels during treatment, suspicion of disease class change, or renal flare.9
The study by Daleboudt and colleagues found, however, that proliferative lesions in the original biopsy rarely switch to pure nonproliferative nephritis during a flare and concluded that repeat biopsy during LN flare is usually not necessary if proliferative lesions were present on the reference biopsy.10
Similarly, in patients with known class III or IV LN, newly active sediment usually indicates a flare of proliferative LN, and a repeat biopsy may not be needed.8 Furthermore, Arends and colleagues reported that repeat renal biopsy in patients with proliferative LN does not offer additional information regarding long-term kidney outcome after immunosuppressive therapy.11 Currently there is no consensus on the indication for repeat biopsy, and its value and clinical relevance continue to be disputed. The ACR guidelines recommend repeat biopsy in those with SLE; however, there are scarce data to support this recommendation.1
Although routine repeat biopsy is not necessary, the decision whether to perform repeat biopsy must be individualized because it is necessary for clinical decision making in some circumstances. For example, repeat renal biopsy is particularly helpful in the decision to begin more aggressive treatment, especially in those with repeated disease flares, because of the potential for cumulative damage that may lead to deterioration of renal function despite successful treatment.12
In fact, studies in both adults and children have found that repeat biopsy during a flare or at the end of the maintenance phase of therapy could guide physicians to safer practices with improved outcomes because histologic evaluation of biopsy can provide additional information that is not captured by routine laboratory evaluation.13-15