[BK virus [BKV] quantification in urine samples of bone marrow transplanted patients is helpful for diagnosis of hemorrhagiccystitis]

Hemorrhagic cystitis [HC] in allogeneic bone marrow transplanted [BMT] patients is associated with BK virus [BKV] reactivation manifested as BK viruria. However, since 77-90% of all adult BMT patients excrete BKV, viral reactivation alone cannot be responsible for HC. Recently, a significant overrepresentation of C[right arrow]G mutations in the Sp1 binding site in the non-coding control region [NCCR] of BKV was shown to be present in HC patients and absent in non-HC patients. We aimed to investigate if this mutation resulted in excessive BKV excretion in HC patients. Study design: A Real-Time PCR was developed and used to quantify BKV in urine samples from 21 patients with HC, with and without the mutations, as well as from patients without HC. A Real-Time PCR was developed and used to quantify BKV in urine samples from 21 patients with HC, with and without the mutations, as well as from patients without HC. Quantification of BKV was successful in 18 of 21 urine patients [six with and six without C[right arrow]G mutations] and six patients without HC. A mean of 3.0x10[6] BKV copies/micro was detected in urine samples of HC patients with C[right arrow]G mutations, compared to a mean of 1.5*10[6] BKV copies/micro L in HC patients without C[right arrow]G mutations and a mean of 10x10[6] BKV copies/ micro L in patients without HC. The obtained differences were however not statistically significant, due to one individual non-HC patient with an extremely high BKV copy number. Nevertheless, while 50% of the samples in the HC groups expressed 1*10[6] copies/micro L or more, only one of the samples in the non-HC group contained a virus quantity higher than 5* 10[5] copies. Although we could not confirm that the C[right arrow]G mutations in the Sp1 site of BKV were responsible for an increased viral load in patients with HC, our data suggest that levels of BKV above 10[4] copies/ micro L may indicate a risk for HC

Correlation of high viral BK load in the urine samples of patients with graft- versus-host with haemorrhagic infectious diseases of bladder after hematopoietic stem cell transplantation

A possible temporal correlation between high BK virus [BKV] load in urine alone or in combination with acute graft versus host disease [GVHD] and the development of hemorrhagic cystitis [HC] was examined in this study. 31 allogeneic hematopoietic stem cell transplanted [SCT] patients were included in this study. BKV DNA was detected by nested and quantitative Real-Time PCR in the urine of 16 out of 31 patients. HC occurred in 6/16 patients with BKV DNA in their urine samples. BKV load was evaluated in the urine samples from 5 of 6 HC patients. Presence of BKV or BKV load >10[6] copies alone in urine samples showed some predictive ability for HC, while acute GVHD alone or conditioning regiments did not. However, during the period after SCT to HC onset a combination of BKV load >10[6] copies and acute GVHD, discriminated the best between HC [4/5] and non-HC [2/25] patients [p=0.003]. This study indicates that BKV DNA and particularly >10[6] BKV copies/microl of urine from SCT patients may have some predictive ability for HC. However, the best association to HC was achieved when a viral load of > 10[6] BKV copies/microl of urine was present in combination with acute GVHD