[Management of genetic renal disorders: local experience and importance of the network]. / Prise en charge des maladies rénales génétiques : expérience locale et importance du réseau.

In nephrology, rare disorders are frequently encountered. In children, about 60% of the renal disorders are rare, with congenital abnormalities of the kidney and urinary tract disorders (CAKUT), being highly prevalent. In adults, about 22% of the disorders leading to renal replacement therapies are rare and include glomerulonephritis and genetic disorders. Rarity may preclude the rapid and extensive access to care for patients suffering of renal disorders, especially in Switzerland, which is small and fragmented. Only collaborative network and access to databases, shared resources and to specific competence may help patient management. Lausanne and Geneva University Hospitals have started specialized outpatient clinics for rare renal disorders several years ago and are part of national and international networks.

Dans le domaine des maladies rénales, la rareté est fréquente. Chez l'enfant, 60 % des maladies touchant les reins sont rares et les malformations de l'axe urinaire sont prépondérantes. Chez l'adulte, près de 22 % des pathologies qui mènent à la maladie rénale terminale sont rares et incluent les glomérulonéphrites et les maladies génétiques. La rareté de ces pathologies fait que les compétences médicales peuvent être difficiles à trouver et l'expérience locale insuffisante. Ainsi, seule la mise en réseau des données, des ressources et des compétences peut permettre d'améliorer la prise en charge de ces patients. Le CHUV et les HUG ont mis en place des consultations spécialisées pour les maladies rénales rares. Elles s'inscrivent dans un réseau national et international.

Predictive Factors of Surgical Complications in the First Year Following Kidney Transplantation.

BACKGROUND: In the recent years, an increased use of marginal donors and grafts and a growing prevalence of peripheral arterial disease in the recipients have been observed. Meanwhile, the open surgical technique for kidney transplantation has not changed. The aim of this study is to analyze all surgical complications occurring in the first year after kidney transplant and to determine potential predictive risk factors. METHODS: Data of the 399 patients who underwent kidney transplant in our University Hospital between January 2006 and December 2015 were retrospectively reviewed. The primary endpoint was the overall rate of vascular, parietal and urological complications at 1 year following kidney transplantation. The secondary outcomes were graft and patient' survival rates, and the identification of predictive factors of the surgical complications. RESULTS: 24% of patients developed 134 complications. Vascular complication represented 39% of all complications and resulted in 9 graft losses. Parietal and urological complications represented 46-15% of all complications, respectively, No parietal or urological complications were associated with graft loss. 5 patients died during the 1st year, none of these cases was associated with graft loss. The graft survival rate reached 96% at 1 year, including patients still alive. The occurrence of surgical complication was associated with reduced graft survival at 1 year. Using a multivariate analysis, 4 predictive factors were identified: age, deceased donor, operative time and dyslipidemia. CONCLUSION: Surgical complications after kidney transplantation remained frequent and age, deceased kidney donors, and operative time were identified as risk factors. As vascular complications were a major cause of early graft loss, efforts should aim to reduce their occurrence to increase graft survival.

Impact of kidney transplantation on sleep apnea severity: A prospective polysomnographic study.

Fluid overload has been associated with a high prevalence of sleep apnea (SA) in patients with end-stage kidney disease (ESKD). In this prospective study, we hypothesized that improvement in kidney function and hydration status after kidney transplantation (Tx) may result in an improvement in SA severity. A total of 196 patients on the kidney Tx waiting list were screened for SA using home nocturnal polysomnography (PSG) to measure the apnea-hypopnea index (AHI) and underwent bioimpedance to assess body composition. Of 88 participants (44.9%) with SA (AHI ≥ 15/h), 42 were reassessed 6 months post-Tx and were compared with 27 control patients. There was a significant, but small, post-Tx improvement in AHI (from 44.2 ± 24.3 to 34.7 ± 20.9/h, P = .02) that significantly correlated with a reduction in fluid overload (from 1.8 ± 2.0 to 1.2 ± 1.2 L, P = .02) and body water (from 54.9% to 51.6%, P = .003). A post-Tx increase in body fat mass (from 26% to 30%, P = .003) possibly blunted the beneficial impact of kidney Tx on SA. All parameters remained unchanged in the control group. In conclusion, SA is a frequent condition in ESKD patients and partially improved by kidney Tx. We suggest that SA should be systematically assessed before and after kidney Tx. ClinicalTrials.gov Identifier: NCT02020642.

Upfront use of eculizumab to treat early acute antibody-mediated rejection after kidney allotransplantation and relevance for xenotransplantation.

Acute antibody-mediated rejection (AMR) early after transplant remains a challenge, both in allotransplantation and in xenotransplantation. We report the case of an early and severe acute AMR episode in a kidney transplant recipient that was successfully treated with upfront eculizumab. A 58-year-old woman had been on dialysis since 2014. She underwent a first kidney transplant in 2018 with primary non-function and received several blood transfusions. Postoperatively, she developed anti-HLA antibodies. One year later, she received a second allograft from a deceased donor. At day 0, there was only one preformed low-level donor-specific antibody (DSA) anti-DQ7. After initial excellent allograft function, serum creatinine increased on days 7-9, and this was associated with oligo-anuria. On day 7, there was an increase in her DSA anti-DQ7 and 4 de novo DSA had developed at high MFI values. Allograft biopsy showed severe active AMR with diffuse C4d deposits in peritubular capillaries. The early acute AMR episode was treated with upfront eculizumab administration (2 doses) with efficient CH50 blockade (< 10% CH50). Rituximab was also administered on day 12, and intravenous immunoglobulin (IVIG) was given over the following days. There was an excellent clinical response to eculizumab administration. Eculizumab administration rapidly reversed the acute AMR episode without the need for plasmapheresis. Rituximab and IVIG were also used as B-cell immunomodulators to decrease DSA. Blocking efficiently the terminal complement pathway may become a useful strategy to treat acute AMR in sensitized recipients of allografts, and possibly in recipients of discordant xenografts.

[SARS-CoV-2 infection and solid organ transplantation]. / Infection à SARS-CoV-2 et transplantation d'organes solides.

Transplantation has become a valid therapeutic option for an increasing number of patients with end-stage organ disease. The emergence of SARS-CoV-2 coronavirus infection and associated disease (COVID-19) has alarmed the transplant community, since recommendations for adequate follow-up of organ transplant recipients during the acute phase of a pandemic are limited. Furthermore, treatment options against COVID-19 disease and adequate adjustment of immunosuppression in at risk patients remain a concern. This review summarizes current knowledge on the incidence and clinical course of SARS-CoV-2 infection in patients with solid organ transplantation. It also discusses therapeutic strategies and provides general recommendations on how to proceed with transplantation programs in a time when health care resources may become scarce.

La transplantation d'organes permet de prolonger et d'améliorer la qualité de vie d'un nombre croissant de patients. Dans le contexte de la pandémie actuelle de l'infection au coronavirus SARS-CoV-2 et de la maladie qui en découle (COVID-19), la communauté de transplantation s'interroge sur le risque encouru par les patients greffés, sur la manière d'assurer un suivi adéquat d'une population à risque, et sur le schéma thérapeutique à adopter en cas de maladie avérée. Dans cet article nous décrivons les connaissances actuelles quant à l'incidence et à l'évolution de l'infection SARS-CoV-2 chez des patients greffés. En accord avec les sociétés de discipline, nous proposons des recommandations de prise en charge thérapeutique, et amenons quelques éléments de réflexion en tenant compte d'une possible limitation des ressources et d'une situation pandémique évolutive.

Genetic immune and inflammatory markers associated with diabetes in solid organ transplant recipients.

New-onset diabetes mellitus after transplantation (NODAT) is a complication following solid organ transplantation (SOT) and may be related to immune or inflammatory responses. We investigated whether single nucleotide polymorphisms (SNPs) within 158 immune- or inflammation-related genes contribute to NODAT in SOT recipients. The association between 263 SNPs and NODAT was investigated in a discovery sample of SOT recipients from the Swiss Transplant Cohort Study (STCS, n1  = 696). Positive results were tested in a first STCS replication sample (n2  = 489) and SNPs remaining significant after multiple test corrections were tested in a second SOT replication sample (n3  = 156). Associations with diabetic traits were further tested in several large general population-based samples (n > 480 000). Only SP110 rs2114592C>T remained associated with NODAT in the STCS replication sample. Carriers of rs2114592-TT had 9.9 times (95% confidence interval [CI]: 3.22-30.5, P = .00006) higher risk for NODAT in the combined STCS samples (n = 1184). rs2114592C>T was further associated with NODAT in the second SOT sample (odds ratio: 4.8, 95% CI: 1.55-14.6, P = .006). On the other hand, SP110 rs2114592C>T was not associated with diabetic traits in population-based samples, suggesting a specific gene-environment interaction, possibly due to the use of specific medications (ie, immunosuppressants) in transplant patients and/or to the illness that may unmask the gene effect.

[Alagille Syndrome]. / Syndrome d'Alagille.

Alagille syndrome is a rare disorder with low physician awareness. It affects multiple organs and thus patient management involves several medical specialties. It is an autosomal dominant disorder with significant intrafamilial variability. The most frequent clinical manifestations are neonatal jaundice, chronic cholestasis as well as cardiac, ocular and skeletal malformations associated with characteristic facial features. Inherited mutations affect the Notch pathway. Although the molecular basis of Alagille syndrome is well defined, no specific targeted therapy exists.

Le syndrome d'Alagille est une pathologie rare et peu connue dans la pratique médicale. Il s'agit d'une affection multisystémique dont la prise en charge implique plusieurs spécialités médicales. Sa transmission se fait sur un mode autosomique dominant avec néanmoins une expression clinique très variable, au sein d'une même famille chez des sujets présentant une même mutation. Ses manifestations cliniques principales sont un ictère néonatal, une cholestase chronique, une atteinte cardiaque, oculaire, squelettique ainsi qu'un faciès caractéristique. Les diverses mutations identifiées et héritées affectent la voie de signalisation Notch. Bien que la physiopathologie soit actuellement relativement bien définie, aucune thérapie ciblée n'est à l'heure actuelle disponible.

Outcomes of Kidney Donors over 60 Years Old: A Single-Center Cohort Study.

AIM: To evaluate outcomes and post-donation kidney function of older living kidney donors (LKD). METHODS: Retrospective analysis of prospective database including all consecutive LKD undergoing laparoscopic nephrectomy in a single center (09/1998-12/2013). LKD aged ≥60 years were compared to younger LKD. Renal function assessed by creatinine levels and estimated glomerular filtration rates (eGFR). Surgical complications classified according to the Clavien-Dindo classification. Bivariate and multivariate analyses using linear mixed effect models were performed to determine factors (age, gender, hypertension status, BMI, choice of better functioning kidney for donation) that might impinge on renal function after donation. RESULTS: 213 LKD were identified: 49 older (median age: 66 years, range: 60-79) and 164 younger (median age: 46, range: 25-59). Mean operative time (149 vs. 152 min, p = 0.69), conversion to laparotomy (n = 1 vs. 3, p = 0.92), grade III-IV complications (n = 4 vs. 2, p = 0.36) were similar. Older had more grade I-II complications (n = 18 vs. 4, p < 0.001). Despite similar pre-donation eGFR (80 vs. 84 ml/min/1.73 m2), older donors presented significantly lower eGFR during inpatient period (46 vs. 51 ml/min/1.73 m2, p = 0.0003), at 1 month (51 vs. 58 ml/min/1.73 m2, p = 0.002) and at 1 year (54 vs. 62 ml/min/1.73 m2, p = 0.001). Multivariate analysis adjusted to gender, hypertension status, BMI and choice of better functioning kidney for donation showed that at 1 year, age ≥60 affected renal function by a coefficient of 0.91 (p < 0.001). CONCLUSION: Despite renal function improvement after discharge, LKD ≥ 60 years presented lower eGFR than younger at one year and had more grade I-II surgical complications.

Multimodal imaging of retinal pigment epithelial detachments in patients with C3 glomerulopathy: case report and review of the literature.

BACKGROUND: To describe the optical coherence tomography angiograhy (OCTA) of drusenoid pigment epithelial detachments (PEDs) in a woman affected by Complement 3 (C3) glomerulopathy, which represents a spectrum of glomerular diseases characterized on fluorescent microscopy by C3 accumulation with absent, or scanty, immunoglobulin deposits. It is due to acquired or genetically defective alternative pathway control and is generally associated with drusen-like deposits in Bruch's membrane, as well as choriocapillaris. These retinal lesions can be associated with choroidal neovascularization and central serous chorioretinopathy (CSCR). OCTA is useful to detect neovascularization without injecting a contrast product, particularly in these patients who may have renal insufficiency. CASE PRESENTATION: A 28-year-old woman affected by C3 glomerulpathy was diagnosed with asymptomatic multiple bilateral PEDs during a routine ophthalmologic consultation. To better characterize the lesions, multimodal imaging was performed and included: optic coherence tomography (OCT), en-face OCT, OCTA, fluorescence and indocyanine angiography. The OCTA clearly identified vascular network rarefaction with decreased choriocapillary vascularization. It confirmed that PEDs associated with C3 glomerulonephritis are not vascularized, but rather of serous type. CONCLUSIONS: Patients affected by C3 glomerulopathy can develop neovascular membranes as retinal complications of pigment epithelial detachments. Optical coherence angiography may be indicated to identify this complication, without injecting any contrast product that could produce further kidney damage.

Influenza vaccination and humoral alloimmunity in solid organ transplant recipients.

Annual influenza vaccination is recommended in solid organ transplant (SOT) recipients. However, concerns have been raised about the impact of vaccination on antigraft alloimmunity. We evaluated the humoral alloimmune responses to influenza vaccination in a cohort of SOT recipients between October 2008 and December 2011. Anti-HLA antibodies were measured before and 4-8 weeks after influenza vaccination using a solid-phase assay. Overall, 169 SOT recipients were included (kidney = 136, lung = 26, liver = 3, and combined = 4). Five (2.9%) of 169 patients developed de novo anti-HLA antibodies after vaccination, including one patient who developed donor-specific antibodies (DSA) 8 months after vaccination. In patients with pre-existing anti-HLA antibodies, median MFI was not significantly different before and after vaccination (P = 0.73 for class I and P = 0.20 for class II anti-HLA antibodies) and no development of de novo DSA was observed. Five episodes of rejection (2.9%) were observed within 12 months after vaccination, and only one patient had de novo anti-HLA antibodies. The incidence of development of anti-HLA antibodies after influenza vaccination in our cohort of SOT recipients was very low. Our findings indicate that influenza vaccination is safe and does not trigger humoral alloimmune responses in SOT recipients.

Expansion and tissue infiltration of an allospecific CD4+CD25+CD45RO+IL-7Ralphahigh cell population in solid organ transplant recipients.

It has been recently shown (Seddiki, N., B. Santner-Nanan, J. Martinson, J. Zaunders, S. Sasson, A. Landay, M. Solomon, W. Selby, S.I. Alexander, R. Nanan, et al. 2006. J. Exp. Med. 203:1693-1700.) that the expression of interleukin (IL) 7 receptor (R) alpha discriminates between two distinct CD4 T cell populations, both characterized by the expression of CD25, i.e. CD4 regulatory T (T reg) cells and activated CD4 T cells. T reg cells express low levels of IL-7Ralpha, whereas activated CD4 T cells are characterized by the expression of IL-7Ralpha(high). We have investigated the distribution of these two CD4 T cell populations in 36 subjects after liver and kidney transplantation and in 45 healthy subjects. According to a previous study (Demirkiran, A., A. Kok, J. Kwekkeboom, H.J. Metselaar, H.W. Tilanus, and L.J. van der Laan. 2005. Transplant. Proc. 37:1194-1196.), we observed that the T reg CD25(+)CD45RO(+)IL-7Ralpha(low) cell population was reduced in transplant recipients (P < 0.00001). Interestingly, the CD4(+)CD25(+)CD45RO(+)IL-7Ralpha(high) cell population was significantly increased in stable transplant recipients compared with healthy subjects (P < 0.00001), and the expansion of this cell population was even greater in patients with documented humoral chronic rejection compared with stable transplant recipients (P < 0.0001). The expanded CD4(+)CD25(+)CD45RO(+)IL-7Ralpha(high) cell population contained allospecific CD4 T cells and secreted effector cytokines such as tumor necrosis factor alpha and interferon gamma, thus potentially contributing to the mechanisms of chronic rejection. More importantly, CD4(+)IL-7Ralpha(+)and CD25(+)IL-7Ralpha(+) cells were part of the T cell population infiltrating the allograft of patients with a documented diagnosis of chronic humoral rejection. These results indicate that the CD4(+)CD25(+)IL-7Ralpha(+) cell population may represent a valuable, sensitive, and specific marker to monitor allospecific CD4 T cell responses both in blood and in tissues after organ transplantation.

Pregnancy after kidney transplantation: an observational study on maternal, graft and offspring outcomes in view of current literature.

Introduction: Pregnancy after kidney transplantation (KTx) is considered to have a high risk of non-negligible complications for the mother, the allograft, and the offspring. With an increased incidence of these pregnancies over the past decades, transplant nephrologists and specialized obstetricians face increasing challenges, with scarce literature regarding long-term outcomes. Methods: We retrospectively collected data from all women with at least one live birth pregnancy after KTx who were followed at our tertiary hospital between 2000 and 2021 to study maternal, graft and fetal outcomes. Results: Ten patients underwent 14 live birth pregnancies after KTx. Preponderant maternal complications were stage 1 acute kidney injury (43%), urinary tract infections (UTI, 43%), progression of proteinuria without diagnostic criteria for preeclampsia (29%), and preeclampsia (14%). Median baseline serum creatinine at conception was 126.5 µmol/L [median estimated glomerular filtration rate (eGFR) 49 mL/min/1.73m2], and eGFR tended to be lower than baseline at follow-ups. Overall, there was no increase in preexisting or occurrence of de novo donor-specific antibodies. No graft loss was documented within the 2-year follow-up. There were nine premature births (64%), with a median gestational age of 35.7 weeks. The median birth weight, height, and head circumference were 2,560 g, 45.5 cm, and 32.1 cm, respectively. These measurements tended to improve over time, reaching a higher percentile than at birth, especially in terms of height, but on average remained under the 50th percentile curve. Discussion: Overall, pregnancies after KTx came with a range of risks for the mother, with a high prevalence of cesarean sections, emergency deliveries, UTI, and preeclampsia, and for the child, with a high proportion of prematurity, lower measurements at birth, and a tendency to stay under the 50th percentile in growth charts. The short- and long-term impact on the allograft seemed reassuring; however, there was a trend toward lower eGFR after pregnancy. With these data, we emphasize the need for a careful examination of individual risks via specialized pre-conception consultations and regular monitoring by a transplant nephrologist and a specialist in maternal-fetal medicine during pregnancy. More data about the long-term development of children are required to fully apprehend the impact of KTx on offspring.

Incidence, Risk Factors, and Management of Incisional Hernias After Kidney Transplant: A 20-Year Single Center Experience.

BACKGROUND: Incisional hernias (IH) constitute a complication after kidney transplant (KT). Patients may be particularly at risk because of comorbidities and immunosuppression. The study aim was to assess the incidence, risk factors, and treatment of IH in patients undergoing KT. METHODS: This retrospective cohort study included consecutive patients who underwent KT between January 1998 and December 2018. Patient demographics, comorbidities, perioperative parameters, and IH repair characteristics were assessed. Postoperative outcomes included morbidity, mortality, need for reoperation, and length of stay (LOS). Patients who developed IH were compared with those who did not develop one. RESULTS: Forty-seven patients (6.4%) developed an IH after a median delay of 14 months (IQR, 6-52 months) in 737 KTs. On uni- and multivariate analyses, body mass index (odds ratio [OR], 1.080; P = .020), pulmonary diseases (OR, 2.415; P = .012), postoperative lymphoceles (OR, 2.362; P = .018), and LOS (OR, 1.013; P = .044) were independent risk factors. Thirty-eight patients (81%) underwent operative IH repair, and 37 (97%) were treated with a mesh. The median LOS was 8 days (IQR, 6-11 days). Three patients (8%) developed surgical site infections, and 2 patients (5%) presented hematomas requiring surgical revision. After IH repair, 3 patients (8%) had a recurrence. CONCLUSIONS: The incidence of IH after KT seems rather low. Overweight, pulmonary comorbidities, lymphoceles, and LOS were identified as independent risk factors. Strategies focusing on the modifiable patient-related risk factors and early detection and treatment of lymphoceles may help to decrease the risk of IH formation after KT.

Differences Between Centers in Psychosocial Evaluations for Living Kidney Donors Do Not Influence Outcome: Results From an Observational Multicenter Study.

Rather little is known about how psychosocial evaluations for living kidney donation (LKD) are performed. We aimed to explore whether Swiss transplant centers (STCs) vary regarding the rate of living kidney donors refused for psychosocial reasons, the psychosocial evaluation process, and the characteristics of the donors. Methods: We investigated 310 consecutive candidates for LKD in 4 of 6 existing STC during mandatory psychosocial evaluations. We registered (i) sociodemographic data, (ii) the type of the decision-making process regarding LKD (ie, snap decision, postponed, deliberate, other), (iii) the evaluator's perception of the donor's emotional bonding and his/her conflicts with the recipient, (iv) the donor's prognosis from a psychosocial perspective, (v) time taken for the psychosocial evaluation, and (vi) its result (eligible, eligible with additional requirements, not eligible). Results: Centers had comparable proportions of noneligible donors (2.9%-6.0%) but differed significantly in the percentage of donors accepted with additional requirements (3.4%-66%, P < 0.001). Significant differences emerged between centers regarding the time needed for evaluation (75-160 min [interquartile range (IQR) 75-180 min] per single exploration, P < 0.001), the perception of the donor's emotional bonding (visual analogue scale [VAS] 8-9 [IQR 6-10], P < 0.001), his/her conflicts with the recipient (VAS 1.5-2 [IQR 0-3], P = 0.006), the donor's psychosocial prognosis (VAS 8-9 [IQR 7-10], P < 0.001), and the type of decision concerning LKD (59%-82% with snap decision "yes," P = 0.008). However, despite differences in the psychosocial evaluation process, the rates of patients accepted for transplantation (eligible and eligible with additional requirements versus noneligible) were comparable across STC (P = 0.72). Conclusions: Our results emphasize that it is more important to establish clear guidelines to identify potential psychosocial risks than to stringently standardize the procedure for psychosocial evaluation of living kidney donors.

Role of post-transplant graft scintigraphy in kidney donation after circulatory death.

Background: There is no consensus on how to predict post-transplant function of donation after circulatory death (DCD) kidneys. Thus, we aimed to identify renal scintigraphy parameters that could predict 1-year kidney function. Methods: In this single center study, we included all consecutive DCD kidney recipients between 2013 and 2021 (n = 29). Patients who did not have a scintigraphy within 10 days of transplantation (n = 3), recipients of multiple organs and less than 18 years old were excluded (n = 1). Primary endpoint was the estimated glomerular filtration rate (eGFR). Results: Median eGFR and serum creatinine at 1 year were 67 µmol/L (56-81) and 111 ml/min (99-132), respectively. Among parameters tested, the 3rd/2nd-minute activity ratio had the best diagnostic performance (AUC: 0.74 and 0.71, for eGFR and creatinine) 1 year post transplantation. Using 1.21 as the best cut off, the 3rd/2nd-minute activity ratio specificity and sensitivity to predict eGFR >60 ml/min was 0.82 and 0.83. Renal function was significantly better at 1 week, 3, 6, and 12 months after transplantation in patients with 3rd/2nd-minute activity ratios above 1.21. Conclusion: This study suggests that the 3rd/2nd-minute activity ratio can predict graft function at 1 year. The benefit of post-transplant scintigraphy should be further validated in a prospective cohort.

Humoral response to the influenza A H1N1/09 monovalent AS03-adjuvanted vaccine in immunocompromised patients.

BACKGROUND: Few data are available regarding the immunogenicity and safety of the pandemic influenza vaccine in immunocompromised patients. We evaluated the humoral response to the influenza A H1N1/09 vaccine in solid-organ transplant (SOT) recipients, in patients with human immunodeficiency virus (HIV) infection, and in healthy individuals. METHODS: Patients scheduled to receive the pandemic influenza vaccine were invited to participate. All participants received the influenza A H1N1/09 AS03-adjuvanted vaccine containing 3.75 µg of hemagglutinin. SOT recipients and HIV-infected patients received 2 doses at 3-week intervals, whereas control subjects received 1 dose. Blood samples were taken at day 0, day 21, and day 49 after vaccination. Antibody responses were measured with the hemagglutination inhibition assay (HIA) and a microneutralization assay. RESULTS: Twenty-nine SOT recipients, 30 HIV-infected patients, and 30 healthy individuals were included in the study. Seroconversion measured by HIA was observed in 15 (52%) of 29 SOT recipients both at day 21 and day 49; in 23 (77%) of 30 at day 21 and 26 (87%) of 30 at day 49 in HIV-infected patients, and in 20 (67%) of 30 at day 21 and in 23 (77%) of 30 at day 49 in control subjects (P = .12 at day 21 and P = .009 at day 49, between groups). Geometric means of antibody titers were not significantly different between groups at day 21 or at day 49. CONCLUSIONS: Influenza A H1N1/09 vaccine elicited a similar antibody response in HIV-infected individuals and in control subjects, whereas SOT recipients had an overall lower response. A second dose of the vaccine only moderately improved vaccine immunogenicity in HIV-infected patients.