The cause of urinary symptoms among Human T Lymphotropic Virus Type I (HLTV-I) infected patients: a cross sectional study

Abstract

Background: HTLV-I infected patients often complain of urinary symptomatology. Epidemiological studies have suggested that these individuals have a higher prevalence and incidence of urinary tract infection (UTI) than seronegative controls. However, the diagnosis of UTI in these studies relied only on patient information and did not require confirmation by urine culture. The purpose of this study was to investigate the role of urinary tract infection (UTI) as the cause of urinary symptoms in HTLV-I infected patients.

Methods: In this cross sectional study we interviewed, and cultured urine from, 157 HTLV-I seropositive individuals followed regularly at a specialized clinic. All patients were evaluated by a neurologist and classified according to the Expanded Disability Status Scale (EDSS). Urodynamic studies were performed at the discretion of the treating physician.

Results: Sixty-four patients complained of at least one active urinary symptom but UTI was confirmed by a positive urine culture in only 12 of these patients (19%); the majority of symptomatic patients (81%) had negative urine cultures. To investigate the mechanism behind the urinary complaints in symptomatic individuals with negative urine cultures, we reviewed the results of urodynamic studies performed in 21 of these patients. Most of them (90.5%) had abnormal findings. The predominant abnormalities were detrusor sphincter hyperreflexia and dyssynergia, findings consistent with HTLV-I-induced neurogenic bladder. On a multivariate logistic regression, an abnormal EDSS score was the strongest predictor of urinary symptomatology (OR 9.87, 95% CI 3.465 to 28.116, P < 0.0001).

Conclusion: Urinary symptomatology suggestive of UTI is highly prevalent among HTLV-I seropositive individuals but true UTI is responsible for the minority of cases. We posit that the main cause of urinary symptoms in this population is neurogenic bladder. Our data imply that HLTV-I infected patients with urinary symptomatology should not be empirically treated for UTI but rather undergo urine culture; if a UTI is excluded, further investigation with urodynamic studies should be considered.

Figures

Figure 1

Prevalence of urinary symptoms and positive urine culture stratified by the degree of neurologic impairment. The gray bars represent the prevalence of urinary symptoms; the white bars, the prevalence of positive urine cultures; and the black bars, the percentage of urinary symptoms that may have been explained by a positive urine culture. Of the 80 patients without neurologic impairment (EDSS = 0.0), 22 (27.5%) had urinary symptoms and 05 (6.3%) had positive urine culture. Of the 42 patients with incipient myelopathy (EDSS 1.0–3.0), 16 (38.1%) had urinary symptoms and 04 (9.5%) had positive urine culture. Of the 33 patients with HAM/TSP (EDSS = 3.0), 24 (72.7%) had urinary symptoms and 07 (21.2%) had positive urine culture. A positive urine culture may explain the urinary symptomatology in 23% (5/22), 25% (4/16), and 29% (7/24) of patients without neurologic involvement, incipient myelopathy, and HAM/TSP, respectively.