X-linked lymphoproliferative disease (also known as "Duncan's disease" or "Purtilo syndrome") is a lymphoproliferative disorder.

Some of the symptoms and signs of IPEX syndrome are the following:

Strangely, in boys with X-linked lymphoproliferative disorder, there is an inability to mount an immune response to the Epstein-Barr virus (EBV), which often leads to death from bone marrow failure, irreversible hepatitis, and malignant lymphoma. However, the connection between EBV and X-linked lymphoproliferative disorder is yet to be determined.

Patients produce insufficient numbers of CD27 memory B cells.

The differential diagnosis of HLH includes secondary HLH and macrophage-activation syndrome or other primary immunodeficiencies that present with hemophagocytic lymphohistiocytosis, such as X-linked lymphoproliferative disease.

Other conditions that may be confused with this condition include autoimmune lymphoproliferative syndrome. As a syndrome of intense inflammation it needs to be differentiated from sepsis, what may be extremely challenging.

The diagnosis of acquired, or secondary, HLH is usually made in association with infection by viruses, bacteria, fungi, or parasites or in association with lymphoma, autoimmune disease, or metabolic disease. Acquired HLH may have decreased, normal, or increased NK cell activity.

Persons afflicted with X-SCID often have infections very early in life, before three months of age. This occurs due to the decreased amount of immunoglobulin G (IgG) levels in the infant during the three-month stage. This is followed by viral infections such as pneumonitis, an inflammation of the lung which produces common symptoms such as cough, fever, chills, and shortness of breath. A telltale sign of X-SCID is candidiasis, a type of fungal infection caused by "Candida albicans". Candidiasis involves moist areas of the body such as skin, the mouth, respiratory tract, and vagina; symptoms of oral candidiasis include difficulty in swallowing, pain on swallowing and oral lesions. Recurrent eczema-like rashes are also a common symptom. Other common infections experienced by individuals with X-SCID include diarrhea, sepsis, and otitis media. Some other common symptoms that are experienced by X-SCID patients include failure to thrive, gut problems, skin problems, and muscle hypotonia.

In some patients symptoms may not appear for the first six months after birth. This is likely due to passive immunity received from the mother in order to protect the baby from infections until the newborn is able to make its own antibodies. As a result, there can be a silent period where the baby displays no symptoms of X-SCID followed by the development of frequent infections.

The onset of HLH occurs under the age of 1 year in ~70% of cases. Familial HLH should be suspected if siblings are diagnosed with HLH or if symptoms recur when therapy has been stopped. Each full sibling of a child with familial HLH has a 25% chance of developing the disease, a 50% chance of carrying the defective gene (which is very rarely associated with any risk of disease) and a 25% chance of not being affected and not carrying the gene defect.

Patients with HLH, especially when untreated, may need intensive therapy. Therefore, HLH should be included in the differential diagnosis of ICU (Intensive Care Unit) patients with cytopenia and hyperferritinemia.

HLH clinically manifests with fever, enlargement of the liver and spleen, enlarged lymph nodes, yellow discoloration of the skin and eyes, and a rash.

The precise symptoms of a primary immunodeficiency depend on the type of defect. Generally, the symptoms and signs that lead to the diagnosis of an immunodeficiency include recurrent or persistent infections or developmental delay as a result of infection. Particular organ problems (e.g. diseases involving the skin, heart, facial development and skeletal system) may be present in certain conditions. Others predispose to autoimmune disease, where the immune system attacks the body's own tissues, or tumours (sometimes specific forms of cancer, such as lymphoma). The nature of the infections, as well as the additional features, may provide clues as to the exact nature of the immune defect.

IPEX (immunodysregulation polyendocrinopathy enteropathy X-linked) syndrome is a rare disease linked to the dysfunction of the transcription factor FOXP3, widely considered to be the master regulator of the regulatory T cell lineage. It leads to the dysfunction of regulatory T-cells and the subsequent autoimmunity. The disorder manifests with autoimmune enteropathy, psoriasiform or eczematous dermatitis, nail dystrophy, autoimmune endocrinopathies, and autoimmune skin conditions such as alopecia universalis and bullous pemphigoid.

Management for immunodysregulation polyendocrinopathy enteropathy X-linked syndrome has seen limited success in treating the syndrome by bone marrow transplantation.

Lymphoproliferative disorders (LPDs) refer to several conditions in which lymphocytes are produced in excessive quantities. They typically occur in people who have a compromised immune system. They are sometimes equated with "immunoproliferative disorders", but technically lymphoproliferative disorders are a subset of immunoproliferative disorders, along with hypergammaglobulinemia and paraproteinemias.

Lymphoproliferative disorders are a set of disorders characterized by the abnormal proliferation of lymphocytes into a monoclonal lymphocytosis. The two major types of lymphocytes are B cells and T cells, which are derived from pluripotent hematopoetic stem cells in the bone marrow. Individuals who have some sort of dysfunction with their immune system are susceptible to develop a lymphoproliferative disorder because when any of the numerous control points of the immune system become dysfunctional, immunodeficiency or deregulation of lymphocytes is more likely to occur. There are several inherited gene mutations that have been identified to cause lymphoproliferative disorders; however, there are also acquired and iatrogenic causes.

X-linked severe combined immunodeficiency (X-SCID) is an immunodeficiency disorder in which the body produces very few T cells and NK cells. In the absence of T cell help, B cells become defective. It is an x-linked recessive trait, stemming from a mutated (abnormal) version of the IL2-RG gene located at xq13.1 on the X-chromosome, which is shared between receptors for IL-2, IL-4, IL-7, IL-9, IL-15 and IL-21.

Primary immunodeficiencies are disorders in which part of the body's immune system is missing or does not function normally. To be considered a "primary" immunodeficiency, the cause of the immune deficiency must not be secondary in nature (i.e., caused by other disease, drug treatment, or environmental exposure to toxins). Most primary immunodeficiencies are genetic disorders; the majority are diagnosed in children under the age of one, although milder forms may not be recognized until adulthood. While there are over 100 recognized PIDs, most are very rare. About 1 in 500 people in the United States are born with a primary immunodeficiency. Immune deficiencies can result in persistent or recurring infections, autoinflammatory disorders, tumors, and disorders of various organs. There are currently no cures for these conditions; treatment is palliative and consists of managing infections and boosting the immune system.

This disease is known for an indolent clinical course and incidental discovery. The most common physical finding is moderate splenomegaly. B symptoms are seen in a third of cases, and recurrent infections due to the associated neutropenia are seen in almost half of cases.

Rheumatoid arthritis is commonly observed in people with T-LGLL, leading to a clinical presentation similar to Felty's syndrome. Signs and symptoms of anemia are commonly found, due to the association between T-LGLL and erythroid hypoplasia.

The leukemic cells of T-LGLL can be found in peripheral blood, bone marrow, spleen, and liver. Nodal involvement is rare.

Immunoproliferative disorders, also known as immunoproliferative diseases or immunoproliferative neoplasms, are disorders of the immune system that are characterized by the abnormal proliferation of the primary cells of the immune system, which includes B cells, T cells and natural killer (NK) cells, or by the excessive production of immunoglobulins (also known as antibodies).

Post-transplant lymphoproliferative disorder (PTLD) is the name given to a B-cell proliferation due to therapeutic immunosuppression after organ transplantation. These patients may develop infectious mononucleosis-like lesions or polyclonal polymorphic B-cell hyperplasia. Some of these B-cells may undergo mutations which will render them malignant, giving rise to a lymphoma.

In some patients, the malignant cell clone can become the dominant proliferating cell type, leading to frank lymphoma, a group of B cell lymphomas occurring in immunosuppressed patients following organ transplant.

The disease is believed to be induced by a combination of Epstein Barr virus infection and immunosuppression through; immunosuppressive drugs (with case reports of methotrexate and azathioprine), infections such as HIV or chronic viral hepatitis or endogenous T-cell defects.

Franklin's disease (gamma heavy chain disease)

It is a very rare B-cell lymphoplasma cell proliferative disorder which may be associated with autoimmune diseases and infection is a common characteristic of the disease. It is characterized by lymphadenopathy, fever, anemia, malaise, hepatosplenomegaly, and weakness. The most distinctive symptom is palatal edema, caused by nodal involvement of Waldeyer's ring.

Diagnosis is made by the demonstration of an anomalous serum M component that reacts with anti-IgG but not anti-light chain reagents. Bone marrow examination is usually nondiagnostic.

Patients usually have a rapid downhill course and die of infection if left untreated or misdiagnosed.

Patients with Franklin disease usually have a history of progressive weakness, fatigue, intermittent fever, night sweats and weight loss and may present with lymphadenopathy (62%), splenomegaly (52%) or hepatomegaly (37%). The fever is considered secondary to impaired cellular and humoral immunity, and thus recurrent infections are the common clinical presentation in Franklin disease. Weng et al. described the first case of Penicillium sp. infection in a patient with Franklin disease and emphasized the importance of proper preparation for biopsy, complete hematologic investigation, culture preparation and early antifungal coverage to improve the outcome.

The γHCD can be divided into three categories based on the various clinical and pathological features. These categories are disseminated lymphoproliferative disease, localized proliferative disease and no apparent proliferative disease.

- Disseminated lymphoproliferative disease is found in 57-66% of patients diagnosed with γHCD. Lymphadenopathy and constitutional symptoms are the usual features.

- Localized proliferative disease is found in approximately 25% of γHCD patients. This is characterized by a localization of the mutated heavy chains in extramedullary tissue, or solely in the bone marrow.

- No apparent proliferative disease is seen in 9-17% of patients with γHCD, and there is almost always an underlying autoimmune disorder.

The IgM type of heavy chain disease, μHCD, is often misdiagnosed as chronic lymphoid leukemia (CLL) because the two diseases are often associated with each other and show similar symptoms.

Lymphomatoid granulomatosis (LYG or LG) is a very rare lymphoproliferative disorder first characterized in 1972 with lymphomatoid meaning lymphoma-like and granulomatosis denoting one of its microscopic characteristics, polymorphic lymphoid infiltrates and focal necrosis within it. While most commonly found in middle age patients, it has been observed in young people with a study identifying 47 cases of patients aged 0–18 years in the literature. Males are found to be affected twice as often as females.

Chronic granulomatous disease (CGD) (also known as Bridges–Good syndrome, chronic granulomatous disorder, and Quie syndrome) is a diverse group of hereditary diseases in which certain cells of the immune system have difficulty forming the reactive oxygen compounds (most importantly the superoxide radical due to defective phagocyte NADPH oxidase) used to kill certain ingested pathogens. This leads to the formation of granulomata in many organs. CGD affects about 1 in 200,000 people in the United States, with about 20 new cases diagnosed each year.

This condition was first discovered in 1950 in a series of 4 boys from Minnesota, and in 1957 it was named "a fatal granulomatosus of childhood" in a publication describing their disease. The underlying cellular mechanism that causes chronic granulomatous disease was discovered in 1967, and research since that time has further elucidated the molecular mechanisms underlying the disease. Bernard Babior made key contributions in linking the defect of superoxide production of white blood cells, to the cause of the disease. In 1986, the X-linked form of CGD was the first disease for which positional cloning was used to identify the underlying genetic mutation.

These disorders are subdivided into three main classes, which are lymphoproliferative disorders, hypergammaglobulinemia, and paraproteinemia. The first is cellular, and the other two are humoral (however, humoral excess can be secondary to cellular excess.)

- "Lymphoproliferative disorders" (LPDs) refer to several conditions in which lymphocytes are produced in excessive quantities. They typically occur in patients who have compromised immune systems. This subset is sometimes incorrectly equated with "immunoproliferative disorders".

- Humoral

- "Hypergammaglobulinemia" is characterized by increased levels of immunoglobulins in the blood serum. Five different hypergammaglobulinemias are caused by an excess of immunoglobulin M (IgM), and some types are caused by a deficiency in the other major types of immunoglobulins.

- "Paraproteinemia" or "monoclonal gammopathy" is the presence of excessive amounts of a single monoclonal gammaglobulin (called a "paraprotein") in the blood.

Classically, patients with chronic granulomatous disease will suffer from recurrent bouts of infection due to the decreased capacity of their immune system to fight off disease-causing organisms. The recurrent infections they acquire are specific and are, in decreasing order of frequency:

- pneumonia

- abscesses of the skin, tissues, and organs

- suppurative arthritis

- osteomyelitis

- bacteremia/fungemia

- superficial skin infections such as cellulitis or impetigo

Most people with CGD are diagnosed in childhood, usually before age 5. Early diagnosis is important since these people can be placed on antibiotics to ward off infections before they occur. Small groups of CGD patients may also be affected by McLeod syndrome because of the proximity of the two genes on the same X-chromosome.

The disease occurs much more in males than females (due to the X-linked recessive pattern of inheritance) and is estimated to occur in between 1 and 10 males per million. The first signs of WAS are usually petechiae and bruising, resulting from a low platelet count. Spontaneous nose bleeds and bloody diarrhea are common. Eczema develops within the first month of life. Recurrent bacterial infections develop by three months. Enlargement of the spleen is not an uncommon finding. The majority of WAS children develop at least one autoimmune disorder, and cancers (mainly lymphoma and leukemia) develop in up to a third of patients. Immunoglobulin M (IgM) levels are reduced, IgA and IgE are elevated, and IgG levels can be normal, reduced, or elevated. In addition to low blood platelet counts (i.e. thrombocytopenia), ~30% of afflicted individuals exhibit eosinophilia, i.e. high blood eosinophil counts.

Wiskott–Aldrich syndrome (WAS) is a rare X-linked recessive disease characterized by eczema, thrombocytopenia (low platelet count), immune deficiency, and bloody diarrhea (secondary to the thrombocytopenia). It is also sometimes called the eczema-thrombocytopenia-immunodeficiency syndrome in keeping with Aldrich's original description in 1954. The WAS-related disorders of X-linked thrombocytopenia (XLT) and X-linked congenital neutropenia (XLN) may present similar but less severe symptoms and are caused by mutations of the same gene.