Protein kinase C δ (PKCδ) deficiency is a rare genetic disorder identified as a monogenic cause of systemic lupus erythematosus in 2013. Since the first cases were described, the phenotype has expanded to include children presenting with autoimmune lymphoproliferative syndrome-related syndromes and infection susceptibility similar to chronic granulomatous disease or combined immunodeficiency. We review the current published data regarding the pathophysiology, clinical presentation, investigation and management of PKCδ deficiency.
Literature review was performed using MEDLINE.
Twenty cases have been described in the literature with significant heterogeneity.
The variation in clinical presentation delineates the broad and critical role of PKCδ in immune tolerance and effector functions against pathogens.

Autoimmune lymphoproliferative syndrome (ALPS) is a rare genetic disease caused germline mutation of FAS gene, gene encoding Fas ligand or Caspase 10 gene. However, in 20% of all ALPS patients, genetic defect is unknown. We presented a case of a 20-year-old male with a history of autoimmune lymphoproliferative syndrome (ALPS; confirmed by genetic study) who came to our medical center with a concern for malignancy. Although no malignancy was detected, his lack of IgA, very low level of IgG (requiring therapy with intravenous IgG) and highly elevated polyclonal IgM (hyperimmunoglobulin M syndrome) were unusual findings because ALPS patients with hypergammaglobulinemia usually demonstrate elevated IgA or IgG.

LPS-responsive beige-like anchor protein (LRBA) deficiency is a primary immunodeficiency caused by a mutation in the LRBA gene. Affected individuals present with a variety of clinical symptoms including hypogammaglobulinemia, recurrent infections, splenomegaly, hepatomegaly, and autoimmune cytopenias. Except for hypogammaglobulinemia, the remaining features resemble autoimmune lymphoproliferative syndrome (ALPS). Here, we report the case of a 14-year-old boy with the ALPS phenotype, eventually diagnosed with LRBA deficiency. He presented with lymphadenopathy and hepatosplenomegaly, along with autoimmune cytopenia. Due to recurrent infections and worsening gastrointestinal symptoms, whole-exome sequencing was conducted and revealed a novel homozygous pathogenic variant in the LRBA gene (c.534del; p.9Asp179IIef*16). The patient recently suffered from clinical deterioration due to SARS-COV-2 which appears to have triggered an acute worsening of his existing Cytomegalovirus colitis leading to an eventual demise. A literature search for reported LRBA deficient patients with ALPS-like phenotype revealed 11 patients. The most common clinical presentations in LRBA patients with ALPS-like phenotype included autoimmunity (100%), splenomegaly (91%), lymphadenopathy (36.4%), and respiratory tract infections (63.6%). LRBA deficiency is unique in the fact that it encompasses immune deficiency, autoimmunity, and lymphoproliferation. In children with multiple symptoms related to these domains, a genetic diagnosis is necessary to ensure tailored and precise medical therapy.

Autoimmune lymphoproliferative syndrome is a primary immunodeficiency caused by variants in FAS-mediated apoptosis related genes and is characterized by lymphadenopathy, splenomegaly and autoimmunity. A total of six different variants in CASP10 have been described as potential causative of disease, although two of them have recently been considered polymorphisms. The high allele frequency of these variants in healthy population in addition to the broad clinical spectrum of the disease difficult the interpretation of their pathogenicity. Here, we describe the clinical and analytical findings of three new patients carrying variants in CASP10 and summarize 12 more cases from the literature. Autoimmune cytopenias, adenopathies and increment of TCRαβ+CD4-CD8- cells have been the most common findings, being possibly the FAS-mediated apoptosis pathway the pathogenic mechanism of this disease. The clinical impact and the consequences of CASP10 variants are not fully elucidated, therefore the description of new cases will contribute to solve this issue.

Autoimmune lymphoproliferative syndrome (ALPS) is a group of genetic disorders characterized by early-onset lymphoproliferation, autoimmune cytopenias, and susceptibility to lymphoma. The majority of ALPS patients carry heterozygous germline mutations in the TNFRSF6 gene. In this study, we conducted a systematic review of patients with ALPS and ALPS-like syndrome.
The literature search was performed in Web of Science, Scopus, and PubMed databases to find eligible studies. Additionally, the reference list of all included papers was hand-searched for additional studies. Demographic, clinical, immunological, and molecular data were extracted and compared between the ALPS and ALPS-like syndrome.
Totally, 720 patients with ALPS (532 genetically determined and 189 genetically undetermined ALPS) and 59 cases with ALPS-like phenotype due to mutations in genes other than ALPS genes were assessed. In both ALPS and ALPS-like patients, splenomegaly was the most common clinical presentation followed by autoimmune cytopenias and lymphadenopathy. Among other clinical manifestations, respiratory tract infections were significantly higher in ALPS-like patients than ALPS. The immunological analysis showed a lower serum level of IgA, IgG, and lymphocyte count in ALPS-like patients compared to ALPS. Most (85%) of the ALPS and ALPS-like cases with determined genetic defects carry mutations in the FAS gene. About one-third of patients received immunosuppressive therapy with conventional or targeted immunotherapy agents. A small fraction of patients (3.3%) received hematopoietic stem cell transplantation with successful engraftment, and all except two patients survived after transplantation.
Our results showed that the FAS gene with 85% frequency is the main etiological cause of genetically diagnosed patients with ALPS phenotype; therefore, the genetic defect of the majority of suspected ALPS patients could be confirmed by mutation analysis of FAS gene.

UNASSIGNED: Protein kinase C is a family of serine/threonine kinases that play a key role in the adaptive immune cell signaling, as well as regulation of growth, apoptosis, and differentiation of a variety of cell types. Patients homozygous for a null mutation of the Protein Kinase C Delta (PRKCD) gene, present clinical feature of immune dysregulation with susceptibility to Epstein-Barr virus infection. However, a minority of patients present the autoimmune lymphoproliferative syndrome (ALPS).
UNASSIGNED: The data were collected by direct interview and examining the patient\'s clinical record. Whole-exome sequencing was performed to detect the underlying genetic mutation in the patient. We also conducted electronic searches for ALPS-like reported patients in PubMed, Web of Science, and Scopus databases.
UNASSIGNED: In this study, we reported a 13-year-old boy who presented with autoimmunity, lymphoproliferation, recurrent pneumonia, cardiomyopathy, and dermatological manifestations. An elevation of double-negative T cells, CD8+ T cells, serum IgG level, as well as a reduction in NK cells, was observed in the patient. A homozygous frameshift mutation (c.1293_1294insA) in exon 13 of the PRKCD gene was confirmed. The literature search showed 39 ALPS-like patients with monogenic defects which only six (15.3%) of them were due to PRKCD genes.
UNASSIGNED: PRKCD should be considered in the context of ALPS clinical manifestations with prominent dermatological involvements.

The authors are reporting a case of autoimmune lymphoproliferative syndrome in a newborn who presented with massive hepatosplenomegaly, thrombocytopenia, and anemia at birth. Antenatal ultrasound revealed a fetus with hepatosplenomegaly. The infant was treated with steroids and sirolimus and is doing well at 4 years of age. This is the first case report of autoimmune lymphoproliferative syndrome presenting as hepatosplenomegaly during fetal life.

The autoimmune lymphoproliferative syndrome (ALPS) is an inborn immunity error, which is the result of a heterogeneous group of mutations in the genes that regulate the apoptosis phenomenon. It typically appears in the first years of life. The most common clinical signs are lymphoid expansion with lymphadenopathy, splenomegaly, and hepatomegaly; immune disease with different types of cytopenia, including thrombocytopenia, hemolytic anemia, and lymphoma. The lab abnormalities that facilitate the diagnosis of ALPS include the presence of double negative alpha/beta T cells, high interleukin levels, vitamin B12 in the blood, and FAS-mediated defective apoptosis in the in vitro assay. The treatment of ALPS is focused on three aspects: The treatment of the manifestations of the disease, the prevention/treatment of complications, and the curative treatment (hematopoietic progenitor cell transplantation [HPCT]). The use of immunosuppressive therapy is suggested only for severe complications of lymphoproliferation or concomitant autoimmune manifestations. Splenectomy is not recommended for autoimmune manifestations in patients with ALPS. HPCT is reserved for selected patients. The survival rate to 50 years is estimated at 85% for patients with FAS deficiency.
El síndrome linfoproliferativo autoinmune (ALPS, autoimmune lymphoproliferative syndrome) es un error innato de la inmunidad, resultado de un grupo heterogéneo de alteraciones en los genes que regulan el fenómeno de apoptosis. Se manifiesta típicamente en los primeros años de vida. Las manifestaciones clínicas más comunes son la expansión linfoide con linfadenopatía, esplenomegalia y hepatomegalia, enfermedad autoinmune con citopenias, incluyendo trombocitopenia y anemia hemolítica, así como linfoma. Las anomalías de laboratorio que facilitan el diagnóstico de ALPS incluyen presencia de células alfa-beta T doble negativas, niveles elevados de interleucina 10, vitamina B12 en sangre y apoptosis defectuosa mediada por FAS en ensayo in vitro. El tratamiento de ALPS se centra en tres aspectos: el tratamiento de las manifestaciones de la enfermedad, la prevención y tratamiento de las complicaciones y el tratamiento curativo (trasplante de células progenitoras hematopoyéticas [TCPH]). Se sugiere el uso de tratamiento inmunosupresor solo para las complicaciones graves de la linfoproliferación o manifestaciones autoinmunes concomitantes. La esplenectomía no se recomienda para las manifestaciones autoinmunes en pacientes con ALPS. El TCPH se reserva para pacientes seleccionados. La tasa de supervivencia a 50 años se estima en 85 % para los pacientes con deficiencia de FAS.

An array of monogenic immune defects marked by autoimmunity, lymphoproliferation, and hyperinflammation rather than infections have been described. Primary immune regulatory disorders pose a challenge to pediatric hematologists and oncologists. This paper focuses on primary immune regulatory disorders including autoimmune lymphoproliferative syndrome (ALPS) and ALPS-like syndromes, immunodysregulation, polyendocrinopathy, enteropathy, X-linked (IPEX) and IPEX-like disorders, common variable immunodeficiency (CVID), CVID-like, and late-onset combined immunodeficiency (CID) disorders. Hyperinflammatory disorders and those associated with increased susceptibility to lymphoid malignancies are also discussed. Using a case-based approach, a review of clinical pearls germane to the clinical and laboratory evaluation as well as the treatment of these disorders is provided.

We described 1 case of autoimmune lymphoproliferative syndrome (ALPS), first diagnosed in our hospital, and reviewed the recent literature. The 11-month old male patient presented with a history of splenomegaly and hepatomegaly since 1 month after birth. He suffered recurrent infectious diseases including cytomegalovirus infection, parvovirus B19 infection and chronic diarrhea disease. Besides, his symptoms included hemolytic anemia and thrombocytopenia. The laboratory abnormality indicated an expanded population of alpha/beta double-negative T cells (DNTs) (27.18% of lymphocytes, 35.16% of CD3+ T lymphocytes) in peripheral blood, and autoantibodies including antinuclear antibody, double-stranded DNA and rheumatic factor were positive. Hyper gamma globulinemia and positive direct Coombs tests were seen in the patient. His parents were both healthy and denied autoimmune diseases. We identified a heterozygous point mutation in exon 3 of the FAS gene carrying c.309 A>C, resulting in a single base pair substitution in exon 3 of FAS gene which changed the codon of Arg103 to Ser103. Unfortunately, we were unable to obtain the gene results of the child\'s parents. The patient was treated with glucocorticoids in our hospital and with mycophenolatemofetil in other hospital. And we were informed that his anemia condition relieved through the telephone follow-up, but he still suffered recurrent infections, hepatomegaly and splenomegaly still existed. As we all know ALPS is characterized by defective lymphocyte apoptosis, and thus cause lymphoproliferative disease and autoimmune disease, and increase the risk of lymphoma. It is more likely to be misdiagnosed as other diseases. ALPS should be suspected in the case of chronic lymphadenopathy, splenomegaly and autoimmune features. Flow cytometry approach is helpful for the diagnosis. Immunosuppressive drugs are the necessary treatment.