Full functional-length urethral sphincter preservation during radical prostatectomy

BACKGROUND

A key prerequisite for urinary continence after radical prostatectomy (RP) is the functional length of the urethral sphincter and the stabilisation of its anatomic position within the pelvic floor.

OBJECTIVE

We describe our modified surgical technique for full functional-length urethra (FFLU) preservation during RP.

DESIGN, SETTING, AND PARTICIPANTS

We analysed 691 consecutive patients who underwent RP over a 12-mo period (285 without and 406 with the FFLU technique).

SURGICAL PROCEDURE

The full functional urethra length was preserved by performing an individualised apical preparation strictly along anatomic landmarks, respecting the individual length of the intraprostatically located proportion of the urethral sphincter. Anatomic fixation of the sphincter was reached by a thorough preservation of the pelvic floor and anatomic restoration of the Mueller's ligaments.

MEASUREMENTS

Continence rates were assessed at 7 d and 12 mo after removal of the catheter. Continence was defined as the use of no pads and no urinary leakage.

RESULTS AND LIMITATIONS

The continence rates were 50.1% and 30.9% 1 wk after catheter removal (p < 0.0001) and 96.9% and 94.7% (p=0.59) at 12 mo after surgery in patients operated on with the FFLU technique versus the non-FFLU technique. In multivariate regression analysis, only the surgical technique correlated significantly with the continence status 1 wk after catheter removal. Neither the overall positive surgical margin rates nor the number of positive margins at the urethral resection border differed significantly between the FFLU and non-FFLU groups (13.6% and 0.5% vs 14.9% and 1.3%, respectively). Although the patients' baseline characteristics were similar in the two surgical groups, the patients were not preoperatively randomised, and the number of patients in the groups was asymmetric.

CONCLUSIONS

The combination of an FFLU preparation and improved preservation of the anatomic fixation of the urethral sphincter complex resulted in significantly increased early urinary continence results.

Biopsies performed at tertiary care centers are superior to referral biopsies in predicting pathologic Gleason sum

OBJECTIVE

Biopsy grading at tertiary care centers may or may not be superior to biopsies performed at referral institutions.

METHODS

Referral biopsy and tertiary care center biopsy Gleason sums were studied in 758 men treated with radical prostatectomy (RP) at a tertiary care center between 1992 and 2004. Grade agreement was calculated using the Cohen kappa (ê). Logistic regression models predicting high-grade prostate cancer at RP were fitted using either referral or tertiary care center biopsies. Comparison of bootstrap-corrected predictive accuracy estimates were performed using the Mantel-Haenszel test.

RESULTS

Grade agreement between biopsy and RP Gleason sum was higher (P = 0.003) for tertiary care center biopsies v referral biopsies (55.5% v 47.9%; P = 0.003). Upgrading occurred in 39.8% of referral biopsies v 32.6% of tertiary care center biopsies (P = 0.03). Tertiary care center biopsies were more accurate in determining RP Gleason sum than referral biopsies (71.5% v 65.6%, P = 0.04).

CONCLUSION

More accurate prediction of RP Gleason grade may be achieved if biopsy is performed and graded at tertiary care centers.

Nerve Distribution along the Prostatic Capsule

OBJECTIVES

Recent literature describes indications for a more-complex course of fibres of the neurovascular bundle (NVB), despite the widely held assumption that it is gathered at the rectolateral side of the prostate. The objective of this study therefore was to determine the typical pattern of nerve distribution along the prostatic capsule.

MATERIALS AND METHODS

Permanent sections of 31 patients, who underwent non-nerve-sparing radical prostectomy (RP) at our institution, were investigated. A total of 186 slides taken from the apex, mid-part, and base of the prostate was analyzed by microscopy. Before microscopy, slides were divided into 12 sectors and numbered clockwise starting from "1" for left ventral sides to "6" for the rectal sides (accordingly, "12"-"7" for right half). Every single nerve and ganglion in the prostatic capsule and the periprostatic tissue was counted in each sector.

RESULTS

The majority of nerves found in the sectors corresponded to the typical location of the NVB at the rectolateral sides of the prostate (4/5 or 8/9 o'clock sectors). In these two sectors, a median of 45.9-65.6% of counted nerves per half was found. However, a significant amount of nerves (21.5%-28.5%) was detected above the horizontal line.

CONCLUSIONS

We conclude that 1/5-1/4 of nerves can be found along the ventral circumference of the prostatic capsule. To preserve a maximum number of nerves, we therefore recommend a modification of the surgical technique by focusing on a high incision for nerve sparing on the ventral parts of the prostate.

Significant upgrading affects a third of men diagnosed with prostate cancer: predictive nomogram and internal validation

OBJECTIVE

To explore the rate of significant upgrading from biopsy to radical prostatectomy (RP) specimens in a contemporary cohort, and to develop a prognostic model capable of predicting the probability of significant upgrading, as previous reports indicate that up to 43% of men with low-grade prostate cancer at biopsy will be diagnosed with high-grade cancer at RP.

PATIENTS AND METHODS

The study cohort comprised 4789 men (median age 63 years, range 39-82) treated with RP, with available clinical stage, prostate-specific antigen levels, biopsy and RP Gleason sum values. These variables were used as predictors in multivariate logistic regression models (LRMs) addressing the rate of significant Gleason sum upgrading, defined as a Gleason sum increase either from < or = 6 to > or = 7 or from 7 to > or = 8 between the biopsy and RP specimens. Regression coefficients were used to develop and validate (200 bootstrap re-samples) a nomogram predicting significant biopsy Gleason sum upgrading.

RESULTS

Significant biopsy Gleason sum upgrading was recorded in 1349 (28.2%) patients. In multivariate LRMs, all predictors were highly significant (all P < 0.001). The bootstrap-corrected accuracy of the nomogram predicting the probability of significant Gleason sum upgrading between biopsy and RP specimens was 75.7%.

CONCLUSION

Our nomogram might prove highly useful when the possibility of a more aggressive Gleason variant could change the treatment options.

[Success rates of two-layer, microsurgical vasovasostomy. Results from a patient questionnaire and comparison with one-layer technique]

Vasovasostomy is the most commonly performed procedures in the therapy for occlusive azoospermia after vasectomy. In our clinic the two-layer microsurgical technique (DL VVST) is considered to be the gold standard. We have examined the results of DL VVST by means of a questionnaire and compared them with those of the monolayer technique (ML VVST).

MATERIALS AND METHOD

In the period from 1996 to 2001, a microsurgical DL VVST with 10 x 0 Prolene sutures under the operation microscope was performed in 141 patient. Aspects of the operation, social aspects and postoperative results (results of spermiogram, birth rates) were assessed by means of a questionnaire. The results were compared with those of a historical patient collective who had undergone a modified monolayer VVST with 7 x 0 Prolene (n = 64).

RESULTS

The questionnaire could be sent to 90/141 patients, the response rate was 63/90 (70 %). The time interval between vasectomy and VVST was on average 9.5 years. The patency rate was 86 %, the birth rate 24 %. Severe or moderately sever complications did not occur. In the historical patient collective, the average occlusion interval was 6.9 years. The patency rate in these patients in whom the VVST was performed merely under the loupe and in a monolayer technique was 87 %, the pregnancy rate 48 %.

CONCLUSION

The highly positive results of VVST with pregnancy rates > 80 % from earlier publications could not be reproduced. According to our results, the two-layer VVST does not afford better results than the monolayer technique.

Immunocyt and the HA-HAase Urine Tests for the Detection of Bladder Cancer: A Side-by-Side Comparison

OBJECTIVES

The reliable detection of bladder cancer from urine specimen remains an unsolved problem. Especially superficial bladder cancer can be missed with urine tests. We assessed the sensitivity and specificity of the commercial Immunocyt test in a side-by-side comparison with the HA-HAase urine test and cytology. The Immunocyt test measures the immunocytological expression of sulfated mucin-glycoproteins and glycosylated forms of the carcinoembryonic antigen in urine. With the HA-HAase urine test the level of hyaluronic acid (HA) and its degrading enzyme hyaluronidase (HAase) are measured in an ELISA-like test.

METHODS

A total of 94 consecutive patients were studied and among these 30 patients had bladder cancer and 64 were controls. Among bladder cancer patients, there were 14 pTa, 9 pT1, 5 pT2 and 2 carcinoma in situ (CIS) transitional cell carcinoma of the bladder, respectively. The controls consisted of 55 patients with a history of bladder cancer but no evidence of tumor at the follow-up cystoscopy and 9 benign prostatic hyperplasia (BPH) patients. The 30 transitional cell cancer specimens had 4 (13%) grade 1 tumors, 15 (50%) grade 2 tumors and 11 (37%) grade 3 tumors. Sensitivity and specificity as well as the positive and negative predictive values of each test were evaluated.

RESULTS

The sensitivity of the HA-HAase urine test (83.3%; 25/30) was significantly higher than the Immunocyt at 63.3% (19/30) (p = 0.038, McNemar test) and cytology (73%; p < 0.05). The specificity of the HA-HAase test (78.1%; 50/64), Immunocyt (75%; 48/64) and cytology (79.7%; 51/64) were comparable. The prevalence of bladder cancer in our study was 31%. The positive predictive value (PPV) of the HA-HAase test (64.1%) was significantly higher than the Immunocyt test (54.3%). The negative predictive value (NPV) of the HA-HAase test (90.9%) was also higher than the Immunocyt test (81.3%). The PPV and NPV values for cytology were 62.9% and 86.4%, respectively. False negative patients in the HA-HAase urine test were 5 pTa tumors (2 G1, 2 G2 and 1 G3). False negative patients in the Immunocyt test were 7 pTa tumors (1 G1 and 6 G2), 3 pT1 (2 G2, 1 G3) and 1 pT2 G3, respectively.

CONCLUSIONS

The sensitivity of the HA-HAase urine test is significantly higher than that of the Immunocyt test to detect bladder cancer. Specificity, as well as the PPV and NPV of the HA-HAase test were higher than that of the Immunocyt test. With a prevalence of 31% bladder cancer patients in all hematuria patients studied, a typical distribution of patients in a urological clinic is presented. Longer follow up of the study patients will give more information on the value of these tests in the detection of bladder cancer.

[Functional results of various surgical techniques for radical prostatectomy]

Radical prostatectomy for the treatment of prostate cancer can be performed by various techniques using a retropubic, perineal, or laparoscopic approach. Besides tumor control, the postoperative urinary continence rates and potency rates impact patients' quality of life after radical prostatectomy. This paper shows the results of our own center and compares the data in the literature regarding functional results of radical prostatectomy with respect to various operative techniques.

Patient-reported sexual function after nerve-sparing radical retropubic prostatectomy

OBJECTIVE

Improved selection criteria have lead to an increasing number of nerve-sparing radical retropubic prostatectomies (RRP) in patients with clinically localised prostate cancer (PCA). Patient questionnaire based outcome analysis on post-operative erectile function after uni- or bilateral nerve-sparing RRP is described.

METHODS

Between January 1992 and March 1999, 366 patients (mean age 62.5 years) underwent uni- or bilateral nerve-sparing RRP at our institution. Indication for nerve-sparing procedure was based on the results of a multivariate classification and regression tree analysis (CART). For evaluation of post-operative patient-reported rates of sexual and erectile function non-validated and validated questionnaires (IIEF 5) were administered after a follow-up of 12 months. Data of five operation periods were analysed.

RESULTS

The unilateral procedure resulted in rates of 13-29% of erections sufficient for unassisted intercourse. Some degree of tumescence was reported by 37-73% of the remaining patients. Bilateral nerve-sparing procedures were almost exclusively performed in periods 3-5, only four patients of period 2 received the bilateral procedure. Here, rates of erections sufficient for intercourse were 25% (period 2), 61% (period 3), 50% (period 4), and 52% (period 5), respectively. Patients with grades 4 and 5 erections had IIEF scores of 19.2 and 20.2 and patients without rigidity or tumescence had scores of 5.7 and 7.0 after uni- and bilateral nerve-sparing procedure, respectively. Patients <60 years of age had better erections than those > or =60 (unilateral: 19% versus 13%, bilateral 45% versus 38%).

CONCLUSION

Compared to a unilateral nerve-sparing procedure, the bilateral nerve-sparing technique revealed much better results inasmuch as about 50% of the patients reported recovery of erections sufficient for sexual intercourse without use of sexual aids.

Testicular germ cell cancer despite previous local radiotherapy to the testis

BACKGROUND

Testicular intraepithelial neoplasia (TIN, also carcinoma in situ of the testis) is the uniform precursor of testicular germ cell cancer. Local radiotherapy to the testis with dosages of 18-20 Gy has been found to safely eradicate TIN and germ cells, too. Thus, the general assumption is that the development of invasive germ cell tumours can be prevented by this radiotherapy.

PATIENTS AND METHODS

Herein, we report two patients with one-sided testicular tumour and biopsy-proven contralateral TIN. Both of them developed germ cell neoplasms in the remaining testis although local radiotherapy with 20 Gy had been applied to the testis.

RESULTS

One patient developed pure seminoma 7 years after completion of radiotherapy, the other developed a combined tumour consisting of embryonal carcinoma and seminoma after 5 years. Treatment consisted of orchiectomy in each of the cases. Histologically, both had TIN in the testicular tissue surrounding the new growths.

CONCLUSIONS

Pathogenetically, a small fraction of radioresistent TIN cells overcoming irradiation and progressing to full-blown germ cell cancer in the later course may be the histogenetic clue to explain these unexpected events. Other explanations, though less probable, could be technical radiotherapeutic failure due to targeting problems and a pre-existing radioresistent germ cell tumour in the irradiated testicle.

[Nerve-sparing radical retropubic prostatectomy. Results of a patient survey]

Improved selection criteria have led to an increasing number of nerve-sparing radical retropubic prostatectomies (RRP) in patients with clinically localized prostate cancer. The results based on patient questionnaires regarding postoperative erectile function are described. Between January 1992 and March 1999, 366 patients (mean age: 62.5 years) underwent uni- or bilateral nerve-sparing RRP at our institution. For evaluation of postoperative patient-reported rates of sexual and erectile function, a questionnaire was used after a follow-up of at least 12 months. Data of five operation periods were analyzed. The results of the unilateral procedure for the five operation periods revealed consistent rates of 13-29% for erections sufficient for intercourse. Bilateral nerve-sparing procedures were almost exclusively performed in periods 3 to 5; only four patients from period 2 underwent the bilateral procedure. The rates of intercourse-sufficient erections were 25% (period 2), 61% (period 3), 50% (period 4), and 52% (period 5), respectively. The results of the unilateral procedure were disappointing. However, the bilateral nerve-sparing method achieved much better results inasmuch as about 50% of the patients reported recovery of erections sufficient for sexual intercourse.

A validated strategy for side specific prediction of organ confined prostate cancer: a tool to select for nerve sparing radical prostatectomy

PURPOSE

Nerve sparing radical prostatectomy for prostate cancer should be restricted to patients who harbor tumors without capsular penetration. To our knowledge the selection criteria for nerve sparing radical prostatectomy are not clearly defined. We investigated a panel of preoperative tumor characteristics with respect to their ability to predict organ confined tumor growth for each lobe of the prostate to indicate unilateral or bilateral nerve sparing radical prostatectomy.

MATERIALS AND METHODS

Nine preoperative tumor characteristics in 278 patients with clinically localized prostate cancer were included in retrospective univariate and multivariate tree structured regression analysis. The association of clinical stage, serum prostate specific antigen (PSA), PSA density, and results of transrectal ultrasound and systematic sextant biopsy, including a quantitative assessment of cancer in the biopsies with organ confined tumor growth, was statistically evaluated. Except for serum PSA and PSA density preoperative characteristics were considered separately for each prostate lobe. Multivariate analysis results were validated prospectively in 353 patients.

RESULTS

On univariate analysis the number of positive biopsies was the most useful single parameter with a positive predictive value of 83% in 274 lobes and a negative predictive value of 55%, followed by mm. of tumor in the biopsy. Of all characteristics included in multivariate analysis only the number of biopsies with high grade cancer, the number of positive biopsies and serum PSA were independent for predicting organ confined cancer. When PSA was less than 10 ng./ml. and not more than 1 biopsy with high grade cancer was identified in a lobe, organ confined tumor growth was present in 86.1% of cases. On prospective validation the same criteria led to an 88.5% incidence of organ confined prostate cancer. Pooling the 2 most favorable groups led to 391 prostate lobes (70.8% of those investigated) with a positive predictive value of 82.1% (95% confidence interval 77.9% to 85.8%). Using the multivariate approach more prostate lobes were assigned to a favorable risk group than on univariate analysis. Clinical stage and simple Gleason grade did not contribute independent information for predicting organ confined disease.

CONCLUSIONS

Quantifying cancer and high grade cancer by systematic biopsy and serum PSA concentration are useful preoperative characteristics for predicting organ confined prostate cancer. Side specific analysis of these parameters is a flexible and reliable tool for selecting patients for nerve sparing radical prostatectomy.

Evaluation of the new automated enzymun-test anti-HBc plus for the detection of hepatitis B virus core antibody

The new automated Enzymun-Test anti-HBc Plus for the detection of antibodies to hepatitis B virus (HBV) core antigen (anti-HBc) after pretreatment with reducing agents dithiothreitol (25 degrees C; + DTT) or potassium bisulfite (37 degrees C; + MBS) was evaluated by testing 571 serum and plasma samples. The panel included dilution series of reference standards and samples from chronic carriers, one seroconversion panel, samples from patients in acute or chronic stage of the disease or resolved hepatitis B, preselected sera from blood donors that were initially reactive in an anti-HBc assay without pretreatment, potentially cross-reactive serum samples obtained from patients suffering from other diseases or with passed infections other than HBV, pregnant women and individuals with HBV vaccination. The IMx CORE(TM) (Abbott Diagnostics) served as reference assay. Discrepant samples were further investigated with two different commercial anti-HBc enzyme immunoassays, other HBV-specific serological markers and HBV DNA hybridization. The sensitivity of the Enzymun-Test Anti-HBc Plus (25 degrees + DTT, and 37 degrees C; + MBS) in comparison to the reference assay was 100%. The IMx CORE showed a twofold higher sensitivity than Enzymun-Test Anti-HBc Plus for anti-HBc detection in dilution series of serum samples from HBV carriers. The agreement in terms of specificity of the Enzymun-Test Anti-HBc Plus (25 degrees C; + DTT, and 37 degrees C; + MBS) and in comparison to IMx CORE was 97.4 and 96.4%, respectively. After resolution of discrepant results (3 samples were tested false negative with IMx CORE), the agreement in terms of specificity of the Enzymun-Test Anti-HBc Plus (25 degrees C; + DTT, and 37 degrees C; + MBS) in comparison to the combination of the comparative assays was 98.3 and 97.4%, respectively. In conclusion, the new automated Enzymun-Test Anti-HBc Plus with sample pretreatment with DTT (25 degrees C; + DTT) or MBS (37 degrees C; + MBS) permits a highly sensitive and specific detection of anti-HBc in diagnostic virology and blood donation testing.

[Treatment of paraphilia and sexually aggressive impulsive behavior with the LHRH-agonist leuprolide acetate]

Up to now there are no published results of therapy of paraphilia (Pedophilia, Sadism) and sexual aggressive impulsiveness with LHRH-(luteinizing hormone-releasing hormone) Agonists in the Germanspeaking countries. In this report we describe 11 patients which were treated with the LHRH-Agonist Leuprolide Acetate in a period of 12 months. The patients showed no tendency of sexual aggressive behaviour and reported an evident reduction of penile erection, ejaculation, masturbation, sexual deviant impulsiveness and fantasies. One patient died from suicide. In combination with other treatments LHRH-Agonists seem to be a very promising alternative to cyproterone acetate and its possible carcinogene effects.

Is intraoperative electrostimulation of erectile nerves possible?

PURPOSE

We improved intraoperative conditions to achieve better corpora cavernosal response to stimulation of the erectile nerves.

MATERIALS AND METHODS

A total of 18 men undergoing nerve sparing retropubic prostatectomy were evaluated with intraoperative stimulation for identification of the erectile nerves. Intracavernosal pressure was measured directly or via electromyography of the corpora cavernosa. Different kinds of anesthesia were used with or without urapidil.

RESULTS

Intracavernosal pressure was recorded in all patients. Use of isoflurane based anesthesia blocked change, and total intravenous anesthesia with propofol resulted in a measurable change in intracavernosal pressure during electrostimulation. However, local urapidil, a potent alpha-blocking agent, doubled or tripled intracavernosal pressure. Electromyography of the corpora cavernosa demonstrated no measurable change.

CONCLUSIONS

Intraoperative electrostimulation of erectile nerves requires special anesthesia as well as local blocking of alpha-receptors. The functional anatomy of the erectile nerves is variable.

Multicenter evaluation of a new rapid automated human immunodeficiency virus antigen detection assay

Although human immunodeficiency virus (HIV) antigen assays are of limited value for monitoring antiretroviral therapy, they play an important role for confirmatory testing of fourth generation HIV screening enzyme immunoassay (EIA) reactive samples. In a multicenter study, a new automated rapid p24 antigen assay, Elecsys HIV Ag (Roche Diagnostics Boehringer Mannheim GmbH, Penzberg, Germany), was compared to FDA licensed tests (Abbott HIV-1 Ag monoclonal and Coulter HIV-1 p24 antigen assay). In the evaluation 27 seroconversion panels were included, sera from the acute phase of infection, single and follow-up samples from HIV antibody positive patients, dilution series of HIV antigen positive standards, sera and cell culture supernatants infected with different HIV-1 subtypes (A-H, and O) HIV-2 and recombinant HIV-1 (gag/env) isolates. To challenge the specificity of the new assay, 2565 unselected blood donors, sera from pregnant women, dialysis and hospitalized patients and 407 potentially cross-reactive samples were investigated. Acute HIV infection was detected in three to eight seroconversion panels earlier with Elecsys HIV Ag than with the alternative assays. Higher numbers of serum samples from HIV infected patients tested positive by Elecsys HIV Ag than with the comparative assays. All HIV-1 subtypes and HIV-2 isolates were recognized with Elecsys HIV Ag. Abbott HIV-1 Ag monoclonal and Coulter HIV-1 p24 antigen assay showed a variable sensitivity for the different HIV-1 subtypes. The specificity of Elecsys HIV Ag and Coulter HIV-1 p24 antigen assay were 99.8 and 99.93%, respectively. All the eight sera that were false reactive by Elecsys HIV Ag were tested negative with the Elecsys HIV Ag Neutralization Test. In conclusion, Elecsys HIV Ag was more sensitive than the alternative assays and showed a high specificity in combination with the neutralization assay. The very short incubation time of 18 min and the fully automated procedure of Elecsys HIV Ag which permits direct testing from the primary patient blood collection tube, represent a major improvement for routine laboratory diagnosis in comparison to the alternative assays.

Reduction of the diagnostic window with a new combined p24 antigen and human immunodeficiency virus antibody screening assay

In order to reduce the window phase between time of human immunodeficiency virus (HIV) infection and laboratory diagnosis, new fourth generation screening assays which permit a simultaneous detection of HIV antigen and antibody have been developed. In a multicenter study, a new automated fourth generation assay, Enzymun-Test HIV Combi (Boehringer Mannheim GmbH) was compared to third generation assay, p24 antigen tests and Western blot. A total of 37 seroconversion panels, samples of the early infection (n = 42), HIV-1 antibody positive sera, including subtypes A E, and O (n = 1118), HIV-2 positive samples (n = 252) and cell culture supernatants infected with different HIV-1 subtypes and HIV-2 (n = 50), blood donors (n = 6649), hospitalized patients (n = 475), HIV neg. sera with indeterminate Western blot (n = 32), potentially cross reactive serum samples (n = 435) and HIV negative specimens from Cameroon (n = 68) were tested. A total of 16 of 29 seroconversions were detected on average 8.5 days earlier with Enzymun-Test HIV Combi than HIV-1/HIV-2 3rd generation EIA (Abbott Laboratories). Overall, in the 29 panels investigated comparatively with the two assays, the mean time delay between Enzymun-Test HIV Combi and HIV-1/HIV-2 3rd generation EIA was 4.7 days. HIV antigen was detected in three out of 35 seroconversions one bleed earlier with HIV-1 Ag Monoclonal than with Enzymun-Test HIV Combi. Enzymun-Test HIV Combi showed a sensitivity of 100% for HIV antibody detection for HIV-1 group M and O and HIV-2 positive specimens. While p24 antigen of different HIV-1 subtypes was detected with Enzymun-Test HIV Combi in all the 49 cell culture supernatants, HIV Ag was not detected in an HIV-2 virus lysate. A total of 66 false positive results out of 7659 HIV negative samples were obtained with the Enzymun-Test HIV Combi. The specificity for unselected blood donors was 99.6%. The Enzymun-Test HIV Combi permits an earlier diagnosis of HIV infection than third generation assays through the detection of p24 antigen, which may be present in serum samples from individuals with recent HIV infection prior to seroconversion and it shows an excellent sensitivity for antibodies to all known HIV-1 subtypes and HIV-2. The specificity in blood donors and hospitalized patients is comparable to that of other assays.