Decreased spermatogonial numbers in boys with severe haematological diseases.

This study examines spermatogonial numbers in testicular samples from 43 prepubertal patients undergoing haematopoietic stem cell transplantation (HSCT). High-dose chemotherapy and/or radiation during HSCT can impact spermatogenesis requiring fertility preservation. Results show that 49% of patients have decreased and 19% severely depleted spermatogonial pool prior to HSCT. Patients with Fanconi anaemia exhibit significantly reduced spermatogonial numbers. Patients with immunodeficiency or aplastic anaemia generally present within the normal range, while results in patients with myelodysplastic syndrome or myeloproliferative neoplasm vary. The study emphasizes the importance of assessing spermatogonial numbers in patients with severe haematological diseases for informed fertility preservation decisions.

Reference standards for follicular density in ovarian cortex from birth to sexual maturity.

RESEARCH QUESTION: Are age-normalized reference values for human ovarian cortical follicular density adequate for tissue quality control in fertility preservation? DESIGN: Published quantitative data on the number of follicles in samples without known ovarian pathology were converted into cortical densities to create reference values. Next, a sample cohort of 126 girls (age 1-24 years, mean ± SD 11 ± 6) with cancer, severe haematological disease or Turner syndrome were used to calculate Z-scores for cortical follicular density based on the reference values. RESULTS: No difference was observed between Z-scores in samples from untreated patients (0.3 ± 3.5, n = 30) and patients treated with (0.5 ± 2.9, n = 48) and without (0.1 ± 1.3, n = 6) alkylating chemotherapy. Z-scores were not correlated with increasing cumulative exposure to cytostatics. Nevertheless, Z-scores in young treated patients (0-2 years -2.1 ± 3.1, n = 10, P = 0.04) were significantly lower than Z-scores in older treated patients (11-19 years, 2 ± 1.9, n = 15). Samples from patients with Turner syndrome differed significantly from samples from untreated patients (-5.2 ± 5.1, n = 24, P = 0.003), and a Z-score of -1.7 was identified as a cut-off showing good diagnostic value for identification of patients with Turner syndrome with reduced ovarian reserve. When this cut-off was applied to other patients, analysis showed that those with indications for reduced ovarian reserve (n = 15) were significantly younger (5.9 ± 4.2 versus 10.7 ± 5.9 years, P = 0.004) and, when untreated, more often had non-malignant haematologic diseases compared with those with normal ovarian reserve (n = 24, 100% versus 19%, P = 0.009). CONCLUSION: Z-scores allow the estimation of genetic- and treatment-related effects on follicular density in cortical tissue from young patients stored for fertility preservation. Understanding the quality of cryopreserved tissue facilitates its use during patient counselling. More research is needed regarding the cytostatic effects found in this study.

Asparaginase encapsulated in erythrocytes as second-line treatment in hypersensitive patients with acute lymphoblastic leukaemia.

Asparaginase is essential in treating acute lymphoblastic leukaemia (ALL). Asparaginase-related hypersensitivity causes treatment discontinuation, which is associated with decreased event-free survival. To continue asparaginase treatment after hypersensitivity, a formulation of asparaginase encapsulated in erythrocytes (eryaspase) was developed. In NOR-GRASPALL 2016 (NCT03267030) the safety and efficacy of eryaspase was evaluated in 55 patients (aged 1-45 years; median: 6.1 years) with non-high-risk ALL and hypersensitivity to asparaginase conjugated with polyethylene glycol (PEG-asparaginase). Eryaspase (150 u/kg) was scheduled to complete the intended course of asparaginase (1-7 doses) in two Nordic/Baltic treatment protocols. Forty-nine (96.1%) patients had asparaginase enzyme activity (AEA) ≥100 iu/l 14 ± 2 days after the first eryaspase infusion [median AEA 511 iu/l; interquartile range (IQR), 291-780], whereas six of nine (66.7%) patients had AEA ≥100 iu/l 14 ± 2 days after the fourth infusion (median AEA 932 iu/l; IQR, 496-163). The mean terminal half-life of eryaspase following the first infusion was 15.3 ± 15.5 days. Few asparaginase-related adverse events were reported; five patients (9.1%) developed clinical allergy associated with enzyme inactivation. Replacement therapy was successfully completed in 50 patients (90.9%). Eryaspase was well tolerated, and most patients had AEA levels above the therapeutic target after the first infusion. The half-life of eryaspase confirmed that a 2-week schedule is appropriate.

Low numbers of COVID-19 in Swedish pediatric oncology patients during the first pandemic year despite an open society.

BACKGROUND: Sweden adopted a different strategy than many other countries to combat the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) pandemic and kept most schools open. Initial reports from China suggested that coronavirus disease 2019 (COVID-19) was milder in children compared to adults, but there was a lack of data from immunocompromised children. Therefore, we investigated the rate of verified SARS-CoV-2 infections in our Swedish pediatric oncology patients. PROCEDURE: This was a multicenter retrospective study. A questionnaire including patient data as well as SARS-CoV-2 data was sent to the six Swedish childhood cancer centers in May 2021. RESULTS: During the first pandemic year, 49 patients were identified as SARS-CoV-2 positive, and 22 (45%) children were hospitalized with COVID-19. Two children needed intensive care, but no COVID-19-related deaths were reported. Most patients (n = 36, 73%) were on active chemotherapy treatment and 23 children (49%) attended school or daycare at least part-time. Half of the SARS-CoV-2-positive patients experienced a delay in cancer treatment. CONCLUSIONS: Despite the rapid spread of SARS-CoV-2 in Sweden, without a strict lockdown of the society, the number of nationally reported pediatric oncology patients with polymerase chain reaction (PCR)-verified infection was low, and the majority of children had mild disease. Our data show that treatment interruptions occurred frequently and this should clearly be avoided for the coming years.

Comparison of primary human cytotoxic T-cell and natural killer cell responses reveal similar molecular requirements for lytic granule exocytosis but differences in cytokine production.

Cytotoxic lymphocytes, encompassing cytotoxic T lymphocytes (CTLs) and natural killer (NK) cells, kill pathogen-infected, neoplastic, or certain hematopoietic cells through the release of perforin-containing lytic granules. In the present study, we first performed probability-state modeling of differentiation and lytic granule markers on CD8(+) T cells to enable the comparison of bona fide CTLs with NK cells. Analysis identified CD57(bright) expression as a reliable phenotype of granule marker-containing CTLs. We then compared CD3(+)CD8(+)CD57(bright) CTLs with NK cells. Healthy adult peripheral blood CD3(+)CD8(+)CD57(bright) CTLs expressed more granzyme B but less perforin than CD3(-)CD56(dim) NK cells. On stimulation, such CTLs degranulated more readily than other T-cell subsets, but had a propensity to degranulate that was similar to NK cells. Remarkably, the CTLs produced cytokines more rapidly and with greater frequency than NK cells. In patients with biallelic mutations in UNC13D, STX11, or STXBP2 associated with familial hemophagocytic lymphohistiocytosis, CTL and NK cell degranulation were similarly impaired. Therefore, cytotoxic lymphocyte subsets have similar requirements for Munc13-4, syntaxin-11, and Munc18-2 in lytic granule exocytosis. The present results provide a detailed comparison of human CD3(+)CD8(+)CD57(bright) CTLs and NK cells and suggest that analysis of CD57(bright) CTL function may prove useful in the diagnosis of primary immunodeficiencies including familial hemophagocytic lymphohistiocytosis.

Spectrum of Atypical Clinical Presentations in Patients with Biallelic PRF1 Missense Mutations.

BACKGROUND: Perforin, encoded by PRF1, is a pore-forming protein crucial for lymphocyte cytotoxicity. Biallelic PRF1 nonsense mutations invariably result in early-onset hemophagocytic lymphohistiocytosis (HLH), termed familial HLH type 2 (FHL2). In contrast, biallelic PRF1 missense mutations may give rise to later-onset disease and more variable manifestations. PROCEDURE: We retrospectively searched our database for patients from families with siblings carrying biallelic PRF1 missense mutations where at least one sibling did not develop HLH, and for patients with biallelic PRF1 missense mutations and an atypical presentation of disease. We reviewed their clinical, genetic, and immunological characteristics. RESULTS: In all, we identified 10 such patients, including three sibling pairs with discordant manifestations. Interestingly, in two families, siblings of late-onset HLH patients developed Hodgkin lymphoma but no HLH. In a third family, one sibling presented with recurrent HLH episodes, whereas the other remains healthy. Of note, the affected sibling also suffered from systemic lupus erythematosus. Additional unrelated patients with biallelic PRF1 missense mutations were affected by neurological disease without classical signs of HLH, gastrointestinal inflammation as initial presentation of disease, as well as a hematological malignancy. Compared to early-onset FHL2 patients, the patients with an atypical presentation displayed a partial recovery of NK cell cytotoxicity upon IL-2 stimulation in vitro. CONCLUSIONS: Our findings substantiate and expand the spectrum of clinical presentations of perforin deficiency, linking PRF1 missense mutations to lymphoma susceptibility and highlighting clinical variability within families. PRF1 mutations should, therefore, be considered as a cause of several diseases disparate to HLH.

Spermatogonia Loss Correlates with LAMA 1 Expression in Human Prepubertal Testes Stored for Fertility Preservation.

Fertility preservation for male childhood cancer survivors not yet capable of producing mature spermatozoa, relies on experimental approaches such as testicular explant culture. Although the first steps in somatic maturation can be observed in human testicular explant cultures, germ cell depletion is a common obstacle. Hence, understanding the spermatogonial stem cell (SSC) niche environment and in particular, specific components such as the seminiferous basement membrane (BM) will allow progression of testicular explant cultures. Here, we revealed that the seminiferous BM is established from 6 weeks post conception with the expression of laminin alpha 1 (LAMA 1) and type IV collagen, which persist as key components throughout development. With prepubertal testicular explant culture we found that seminiferous LAMA 1 expression is disrupted and depleted with culture time correlating with germ cell loss. These findings highlight the importance of LAMA 1 for the human SSC niche and its sensitivity to culture conditions.

Determination of blood cell subtype concentrations from frozen whole blood samples using TruCount beads.

BACKGROUND: In many studies it would be advantageous if blood samples could be collected and analyzed using flow cytometry at a later stage. Ideally, sample collection should involve little hands-on time, allow for long-term storage, and minimally influence the samples. METHODS: Here we establish a flow cytometry antibody panel that can be used to determine granulocytes, monocytes, and lymphocyte subset concentrations in fresh and frozen whole blood using TruCount technology. RESULTS: The panel can be used on fresh whole-blood samples as well as whole-blood samples that have been frozen after mixing with 10% DMSO. Concentrations in frozen and fresh sample is highly correlated both when frozen within 4 h and the day after collection (r ≥ 0.98), and the estimated concentration in frozen samples was between 91 and 94% of that in fresh samples for all cell types. CONCLUSION: Using this method whole-blood samples can be frozen using a simple preparation method, and stored long-term before accurate determination of cell concentration. This allows for standardized analysis of the samples at a reference laboratory in multi-center studies. © 2016 International Clinical Cytometry Society.