Isolated microscopic haematuria in the genitourinary clinic: the value of renal biopsy

Urine erythrocyte morphology in patients with microscopic haematuria caused by a glomerulopathy

The evaluation of urinary erythrocyte morphology (UEM) has been proposed for patients with isolated microscopic haematuria (IMH) to early orientate the diagnosis towards a glomerular or a nonglomerular disease. However, to date, the role of this test in patients with IMH has very rarely been investigated. Sixteen patients (ten children, six adults) with persistent IMH classified as glomerular on the basis of repeated UEM evaluations (55 urine samples, two to eight per patient) were submitted to renal biopsy. This showed a glomerular disease in 14/16 patients (87.5%) (nine thin basement membrane disease; three Alport syndrome; two other), whereas in two patients, no abnormalities were found. Of four microscopic criteria investigated to define a IMH as glomerular, >80% dysmorphic erythrocytes were not found in any sample, >or=40% dysmorphic erythrocytes alone were seen in seven samples (12.7%), >or=5% acanthocytes alone in 15 samples (27.3%) and erythrocytic casts in six samples (10.9%). There was >or=40% dysmorphic erythrocytes associated with >or=5% acanthocytes in 25 samples (45.5%). Sensitivity and positive predictive values in diagnosing a glomerular haematuria were 59.2% and 90.6%, respectively, for >or=40% dysmorphic erythrocytes, 69.4% and 85% for >or=5% acanthocytes/G1 cells and 12.2% and 100% for erythrocytic casts. Our findings demonstrate that the evaluation of UEM is useful to identify patients with an IMH of glomerular origin.

Is sexual intercourse a significant cause of haematuria?

OBJECTIVES

To determine whether recent sexual intercourse might be a cause of microscopic haematuria in patients referred to a urological unit following dipstick detection of urinary haemoglobin.

SUBJECTS AND METHODS

Forty-eight volunteers (24 men and 24 women) consented to have heterosexual intercourse with their regular partner, and to provide samples of urine for testing before and from the first void on the morning after intercourse. After appropriate instruction, volunteers tested their own urine for the presence of blood using standard dipsticks. Any volunteer with haematuria either before or after intercourse was offered a standard haematuria assessment. The results were analysed using the chi-squared test.

RESULTS

None of the volunteers tested positively for haematuria immediately before sexual intercourse; six of the 24 women (25%), but no men, became positive after intercourse (P < 0.01). Only one of the six women accepted the offer of a haematuria evaluation and no pathology was identified.

CONCLUSION

These results suggest that up to a quarter of women develop microscopic haematuria as a direct result of sexual intercourse. A history of recent sexual intercourse should therefore be considered when assessing the clinical significance of microscopic haematuria in women.