Confirming high prevalence of human herpesvirus 8 infection in chronic kidney disease patients in São Paulo, Brazil.

Sir,

Human herpesvirus 8 (HHV-8) is frequently associated with Kaposi's sarcoma. It can be transmitted through organ transplantation or reactivated by immunosuppressive therapy. Chronic kidney disease (CKD) patients are at risk of this infection [1]. The present study aimed to determine the seroprevalence of HHV-8 in CKD patients in São Paulo, Brazil. The study was approved by the research ethics committees at participating institutions.

Blood samples collected from 805 CKD patients attended Hospital do Rim e Hipertensão and/or Santa Casa de Misericórdia de São Paulo (São Paulo, Brazil) were tested for latent and lytic HHV-8-specific antibodies using indirect immunofluorescence assays at Instituto Adolfo Lutz in São Paulo, Brazil, as previously described [2]. The chi-square test and/or Fisher's exact test were performed for comparing categorical variables and HHV-8 serum status, using SPSS for Windows. Of the 805 CKD patients, 61.4% were males, 61.5% white, 35.5% black/pardum and 3.0% yellow. The mean age was 58 years (18–91). Two hundred ninety-five patients were on haemodialysis (HD), 54 on peritoneal dialysis (PD) and 456 not yet on renal replacement therapy (RRT).

One hundred forty-five (18.0%) CKD patients were found HHV-8-seropositive, of whom 56 (18.9%) were on HD, 8 (14.8%) on PD and the remaining 81 (17.7%) were not on any RRT. Examination of these different groups revealed no statistical significant differences (P = 0.963). Further statistical analyses were conducted without this sub-grouping by RRT received. Table 1 discloses the comparison between HHV-8-seronegative and HHV-8-seropositive groups. Patients HHV-8-seropositive had a higher prevalence of previous transplant as well as higher prior exposure to sexually transmitted diseases. Of note, 57.0% of CKD patients who had syphilis also had HHV-8-seropositivity (P = 0.021). Other variables showed lack of association with HHV-8 serological results.

Table 1

Comparison between HHV-8-seronegative and HHV-8-seropositive groups

	HHV-8 seronegative	HHV-8 seropositive	P-value
Age (n = 805)	56.6 ± 16.5	59.3 ± 17.8	0.075
Gender (n = 805)			0.574
Male	408 (61.8%)	86 (59.3%)
Colour/race (n = 805)			0.798
White	407 (61.7%)	88 (60.7%)
Pardum	129 (19.1%)	30 (20.7%)
Black	106 (16.1%)	21 (14.5%)
Yellow	18 (2.7%)	6 (4.1%)
Type of dialysis (n = 349)			0.748
Haemodialysis	239 (36.2%)	56 (38.6%)
Peritoneal dialysis	46 (7.0%)	8 (5.5%)
Immunosuppressive therapy (n = 803)			0.952
Yes	31 (4.7%)	7 (4.8%)
Blood transfusion (n = 793)			0.385
None	374 (57.5%)	80 (55.9%)
One	126 (19.4%)	23 (16.1%)
Many	150 (23.1%)	40 (28.0%)
Transplantation (n = 805)			>0.0001
None	629 (95.3%)	124 (85.5%)
Kidney	27 (4.1%)	20 (13.8%)
Others	4 (0.6%)	1 (0.7%)
Sexuality (n = 717)			0.086
Heterosexual	588 (99.5%)	123 (97.6%)
Homosexual	3 (0.5%)	2 (1.6%)
Bisexual	0 (0.0%)	1 (0.8%)
Personal antecedents (n = 723)			0.484
Yes	565 (95.0%)	124 (96.9%)
HIV (n = 723)			0.096
Yes	6 (1.0%)	4 (3.1%)
STDs (n = 710)			0.003
Yes	10 (1.7%)	8 (6.4%)

Personal antecedents: use of intravenous drugs, use of condom, cytomegalovirus and hepatitis; STDs: sexually transmitted diseases; n: number.

High HHV-8 seroprevalence was observed in CKD patients in São Paulo, Brazil [3]. Interestingly, in the present study, similar proportions of HHV-8-seropositivity were observed in pre-dialysis and dialysis patients suggesting that dialysis proceedings were not related to HHV-8 transmission/acquisition. Another result was the strong association between HHV-8-seropositivity and previous transplant presenting another route of viral transmission as previously reported [4]. The association between HHV-8-seropositivity and syphilis could suggest that the syphilis lesions facilitate the entrance of the virus during sexual intercourse.

Finally, several studies conducted worldwide have attempted to find the best immunosuppressive therapy for use with HHV-8-seropositive transplant recipients [5]. It is not yet defined, but it is certain that these patients need an appropriated attendance to avoid iatrogenic KS and organ rejection, giving them perhaps a better quality of life after transplant. Therefore, due to the high HHV-8 seroprevalence found in the present study and the seriousness of the HHV-8-associated diseases, the authors suggest that screening for HHV-8 must be performed in CKD patients, even those in pre-dialysis.