Clinical Outcomes of Administration of Rituximab for Desensitization in Liver Transplant Patients with Preformed Donor-Specific Antibodies: A Single-Center Experience

BACKGROUND The management and fate of liver transplant (LT) recipients with preformed donor-specific antibodies (pDSA) remain controversial. The aim of this study was to evaluate the clinical impact of rituximab desensitization on pDSA in LT recipients. MATERIAL AND METHODS This retrospective observational study enrolled 120 LT patients aged ≥18 years. Patients with pDSA were administered 500 mg/body rituximab 1-21 days before LT, except for those who had an active infection or had insufficient time to receive rituximab. We allocated patients to groups with or without pDSA, and then divided patients with pDSA into rituximab (+) and rituximab (-) groups for further analysis. RESULTS Twenty-three patients (19.2%) with pDSA were identified. Of these, 18 received rituximab and 5 did not receive rituximab. No patients developed adverse events related to rituximab. In both groups, the levels of pDSA class I in all patients were decreased immediately after LT, whereas those of pDSA class II decreased slowly. There were no significant differences in pathology findings and overall survival between patients with pDSA who were rituximab (+) or rituximab (-), and between patients with or without pDSA. CONCLUSIONS Rituximab desensitization for LT patients with pDSA was managed successfully without significant complications. Due to the small sample size, we could not demonstrate the benefit of rituximab desensitization for LT patients compared with the rituximab (-) group. Additionally, clinical outcomes in patients with pDSA, with or without rituximab, were similar to those without pDSA. Rituximab desensitization might be not essential for LT.

Living Donor Liver Transplantation in Patients with Preformed Donor-Specific Anti-Human Leukocyte Antigen Antibodies Using Preoperative Desensitization Therapy According to Intensity of Donor-Specific Antibodies: A Single-Center Study

BACKGROUND In liver transplantation (LT), preoperative desensitization therapy is considered necessary in patients positive for donor-specific anti-human leukocyte antigen antibodies (DSAs). However, the relationship between DSA intensity and the necessary desensitization therapy is unclear. MATERIAL AND METHODS A total of 37 adult living donor (LD) LTs performed between January 2016 and March 2022 were examined. Mycophenolate mofetil (MMF) was administered preoperatively in DSA-positive cases with positive lymphocyte cross-matching who underwent LDLT. In those with strongly positive DSA (mean fluorescence intensity 10 000), rituximab was administered 2 weeks before LDLT in addition to MMF. Cross-reactive epitope group antigen (CREG)-alone-positive cases were also treated with preoperative MMF when lymphocyte cross-matching was positive. RESULTS Of the 37 patients, 9 were DSA-positive, 7 were CREG-alone-positive, and the others were double-negative. Of 9 DSA-positive cases, desensitization therapy was performed in 7, among which rituximab administration was performed in 3 strongly DSA-positive cases. Of 7 CREG-alone-positive cases, 2 were lymphocyte cross-match-positive and underwent desensitization therapy. The 1-year survival rate was 100% in both DSA- and CREG-alone-positive cases. The frequency of T-cell mediated rejection in DSA-positive, CREG-alone-positive, and double-negative cases was 22%, 43%, and 29%, respectively, with no significant difference. Antibody-mediated rejection occurred in only 1 patient, who was strongly DSA-positive and blood-group incompatible. There was also no significant difference among the 3 groups in terms of the frequency of biliary complications or 90-day mortality. CONCLUSIONS Satisfactory LDLT results were achieved in DSA- and CREG-alone-positive cases following desensitization therapy.

Adherence to Subcutaneous Allergen Immunotherapy in Southeast Turkey: A Real-Life Study

BACKGROUND Subcutaneous immunotherapy (SCIT) in allergic rhinitis (AR) and asthma is a very effective treatment, but adherence is still a serious problem. Studies addressing real-life adherence to SCIT are rare in the literature. The aim of this study was to evaluate the adherence to SCIT in AR and asthma. MATERIAL AND METHODS The medical records of patients prescribed SCIT for treatment of AR and/or asthma were evaluated. Patients who continued the SCIT treatment as prescribed were defined as adherent, patients who stopped the treatment before the recommended period were defined as nonpersistent, and those who never started the treatment were defined as primary poor adherence. Age, gender, residence, type of SCIT, comorbidities, occupation, income, and adverse reactions were evaluated between these groups. RESULTS Ninety-five patients prescribed SCIT for the treatment of AR and/or asthma formed our cohort (female/male: 51/44). The mean (SD) age and duration of SCIT were 32.2±10.0 (range, 17-63) years, 14.4±12.7 (1.0-58.5) months, respectively. Sixty-two (65.3%) patients were adherent, (28.4%) patients were nonpersistent, and 6 (6.3%) patients were primary poor adherent. Nineteen (21.4%) patients had local adverse reactions and one (1.1%) had anaphylaxis. There were no differences between groups for age, gender, residence, type of SCIT, comorbidities, income, or occupation. The most frequent reason of nonpersistence was the cost of treatment. CONCLUSIONS Our study found that adherence to SCIT is low in a real-life setting in southeast Turkey, similar to most previous adherence studies.

Induction of Bronchial Tolerance After 1 Cycle of Monophosphoryl-A-Adjuvanted Specific Immunotherapy in Children With Grass Pollen Allergies

PURPOSE

Subcutaneous allergen-specific immunotherapy (SCIT) is a well-established and clinically effective method to treat allergic diseases, such as rhinitis and asthma. It remains unclear how soon after initiation of an ultra-short course of grass pollen immunotherapy adjuvanted with monophosphoryl lipid A (MPL)-specific bronchial tolerance can be induced.

METHODS

In a prospective study of 69 children double-sensitized to birch and grass pollens (51 males, average age 11.1 years), development of bronchial tolerance after 1 cycle of SCIT for grass was evaluated. In all the patients, the bronchial allergen provocation test (BAP) was performed before and after treatment. According to the results of the first BAP, the patients were divided into 2 groups: those showing a negative BAP with a decrease in FEV1 of <20% (seasonal allergic rhinitis [SAR] group, n=47); and those showing a positive BAP with a decrease in FEV1 of ≥20% (SAR with allergic asthma [SAR and Asthma] group, n=22). All the patients received MPL-adjuvanted, ultra-short course immunotherapy for birch, but only those with a positive BAP to grass received MPL-SCIT for grass.

RESULTS

After the pollen season, the BAP in the SAR group remained unchanged, while it was improved in the SAR and Asthma group (decrease in FEV1 of 28.8% vs 12.5%, P<0.01). The IgG4 levels increased after SCIT (median before SCIT 0.34 to 11.4 after SCIT), whereas the total and specific IgE levels remained unchanged.

CONCLUSIONS

After 1 cycle of MPL-SCIT, specific bronchial tolerance may be significantly induced, whereas in patients without SCIT, bronchial hyperactivity may remain unchanged.

Specific immunotherapy (SIT) in the treatment of allergic rhinitis

Scientific background

Allergic rhinitis (AR) exhibits a prevalence of approx. 20% in Germany and causes enormous costs in the health care system. Specific immunotherapy (SIT) is considered to be the only potentially causal therapy for AR and mainly administered by two routes, subcutaneous (SCIT) and sublinguale (SLIT). SIT promises a reduction of symptoms and the need for medication in patients with AR.

Research questions

The question arises, to what extent is SIT effective and cost effective in the treatment of AR and which ethical-social and legal aspects have to be considered regarding its application.

Methods

The literature search was accomplished in the electronic data bases MEDLINE, EMBASE etc. in February 2008. The medical evaluation was based on systematic reviews of blinded, randomised controlled studies (RCT). The economic evaluation included health-economic studies on the basis of RCT. Additionally, it was also searched for publications explicitly addressing ethical-social and legal aspects of the use of SIT.

Results

Discussion

The topic of the report is very broad, so that the evidence is summarised using systematic reviews. In particular the statistic heterogeneity of the studies found in the reviews considerably limits the strength of the findings. The included health economic studies show different methodical flaws, the largest potential bias is the projection of the magnitude of the medium-term clinical effects on the time period of nine years.

Conclusions

The effectiveness of SIT in patients with AR is not equally proven for all SIT administration forms and allergens. For SCIT and SLIT with grass pollen allergens short and medium-term effectiveness can be regarded as proven. These therapy forms should be used if the indication is appropriate and if no contraindications are present. Also SCIT and SLIT with other seasonal allergens such as tree pollen allergens can be an effective treatment option, but used with a certain restraint due to insufficient data especially in the case of SLIT. For SIT with house dust mite allergens and further perennial allergens no consistent proof of effectiveness are to be determined from the available information. Further research addressing non-grass pollen-associated SIT, allergen and manufacturer specific evaluations as well as asthma prevention is needed. Due to the lack of evidence the use of SIT can not be seen proven as cost effective. To provide such evidence further health economic studies with a long term follow-up are needed. The informed consent of the patients is an important ethical requirement within the use of SIT.

Changes of serum cytokines after the long term immunotherapy with Japanese hop pollen extracts

Japanese hop (Hop J) pollen has been considered as one of the major causative pollen allergens in the autumn season. We developed a new Hop J immunotherapy extract in collaboration with Allergopharma (Reinbeck, Germany) and investigated immunologic mechanisms during 3 yr immunotherapy. Twenty patients (13 asthma with rhinitis and 7 hay fever) were enrolled from Ajou University Hospital. Sera were collected before, 1 yr, and 3 yr after the immunotherapy. Changes of serum specific IgE, IgG1, and IgG4 levels to Hop J pollen extracts and serum IL-10, IL-12, TGF-beta1 and soluble CD23 levels were monitored by ELISA. Skin reactivity and airway hyper-responsiveness to methacholine were improved during the study period. Specific IgG1 increased at 1 yr then decreased again at 3 yr, and specific IgG4 levels increased progressively (p<0.05, respectively), whereas total and specific IgE levels showed variable responses with no statistical significance. IL-10, TGF-beta1 and soluble CD23 level began to decrease during first year and then further decreased during next two years with statistical significances. (p<0.05, respectively). In conclusion, these findings suggested the favorable effect of long term immunotherapy with Hop J pollen extracts can be explained by lowered IgE affinity and generation of specific IgG4, which may be mediated by IL-10 and TGF-beta1.